240sx lack of power

[Ka24de240sxS13]

alright so Ive had my s13 running with a rebuilt motor for about a year now and i have always had a lack of power. the car doesn't pull very hard compared to my friends 240sx which are both stock KA's. -my first fix was NGK iridium spark plugs, checked the resistance of the wires, and gap of the plugs. - I adjusted the timing to 20 degrees ahead. (after this i noticed that the car seemed to misfire randomly.) but it did pick up a little bit. -new air filter

so im confused as to what my next step should be. i want my car to run like its supposed to.

[kingtal0n]

it lacks power because it lacks a turbo.

even if its tuned to peak performance potential, your power is limited to displacement and rpm alone with a peak VE% of 100~... basically a pointless process unless you spin some insane rpm with something larger than 3liters

your basic lack of OOMF is most likely due to timing. if it was fuel related it would be more obvious, you sound to me like it runs, but s***ty/slow, and unless you have a compression leak or a sock in your intake manifold... its probably incomplete combustion due to inadequate ignition timing...

and even if you fix the timing.. yeah you might pick up 40ft/lbs of torque and 25 horsepower or w/e... swapping in an OEM sr20 will double what you COULD have with it running right naturally aspirated.

[Ka24de240sxS13]

it lacks power because it lacks a turbo.

lol come on! i realize its not a 300hp car, I just want it to run at its fullest potential and im not sure where to turn and what to check.

[kingtal0n]

check:compression on all 4timing, actual knock as seen by the ECUair fuel ratio downstreamleakdown on all 4

and you will find the answer somewhere in that mess 99%

[liquid_cool]

turbo turbo..everyone loves em, or the easy sr swapp...

if ya wana burn the fuel compleatly...try a MSD ignition coil and system...this will increase your spark to 4 megajewels..put it this way...dont touch the friggin wires..you will regret it..lol...if you get a MSD6A or better..you get the multispark feature..that sparks for 20 degree's at idle..and has massive spark at mid and wide open throttles...this will improve your throttle responce..

now the wierd miss...you may have a slight headgasket leak that is just letting in a slight amount of coolant creating a vapor lock situation...its fine for now..till the locks become big..and really noticable..at that point..you need to dump the fluids and change the gasket out..thats IF..your vapor locking..if you let it get bad..you could bend a rod or worse...put one throu the block..

hope this gave ya some 411..good luck.

[kingtal0n]

turbo turbo..everyone loves em, or the easy sr swapp...

if ya wana burn the fuel compleatly...try a MSD ignition coil and system...this will increase your spark to 4 megajewels..put it this way...dont touch the friggin wires..you will regret it..lol...if you get a MSD6A or better..you get the multispark feature..that sparks for 20 degree's at idle..and has massive spark at mid and wide open throttles...this will improve your throttle responce..

now the wierd miss...you may have a slight headgasket leak that is just letting in a slight amount of coolant creating a vapor lock situation...its fine for now..till the locks become big..and really noticable..at that point..you need to dump the fluids and change the gasket out..thats IF..your vapor locking..if you let it get bad..you could bend a rod or worse...put one throu the block..

hope this gave ya some 411..good luck.

#1 please dont put an MSD anything on a stock KA#2 all that stuff he just said about leaks and vapor lock and bulls*** is just basically do a leakdown test like I already mentioned

[liquid_cool]

#1 please dont put an MSD anything on a stock KA#2 all that stuff he just said about leaks and vapor lock and bulls*** is just basically do a leakdown test like I already mentioned

i know from experience man...dont flame unless you reaserch some one..follow the links and look at my myspace pics...i recomend thisngs couse they work!...and i have pics to back it up..i allso have been rebuilding motors for a good 20 years..yourself?..dont be a dushbag keyboard cowboy..reaserch and you will find ..my info is correct.

link: http://www.myspace.com/liquid_cool_ka24de in the pics man.

[kingtal0n]

i know from experience man...dont flame unless you reaserch some one..follow the links and look at my myspace pics...i recomend thisngs couse they work!...and i have pics to back it up..i allso have been rebuilding motors for a good 20 years..yourself?..dont be a dushbag keyboard cowboy..reaserch and you will find ..my info is correct.

link: http://www.myspace.com/liquid_cool_ka24de in the pics man.

not trying to flame just dont see any reason why he should spend that much $$ on a f***ing MSD for his STOCK KA when he should be saving every penny to change out that hunk of garbage asap

whats he gonna get, 2MPG and an easier starting? give me a break he isnt building an engine

oh and more to my point if its vapor locking and the HG is leaking and s*** even MORE reason why he doesnt need to buy an MSD ignition and waste $$$ on a dead hunk of trash

telling him buy an MSD and oh yeah your HG might be blown... priceless

[1KleenS13]

MSD's in any car are a waste of money and unreliable. (Unless its a balls out drag car and they carry spares because the things flake out all the time) Do a leak down test. I dont like the idea of you advancing your timing, you could have done damage to hard parts in the engine. I would also put regular plugs in the car, all that fancy crap is basically useless.

[liquid_cool]

not trying to flame just dont see any reason why he should spend that much $$ on a f***ing MSD for his STOCK KA when he should be saving every penny to change out that hunk of garbage asap

whats he gonna get, 2MPG and an easier starting? give me a break he isnt building an engine

oh and more to my point if its vapor locking and the HG is leaking and s*** even MORE reason why he doesnt need to buy an MSD ignition and waste $$$ on a dead hunk of trash

telling him buy an MSD and oh yeah your HG might be blown... priceless

i dont know what forum you came from man..but we dont treat other nicco members like you are trying to do here..we help others with the info given..its information to get them going in the rite direction..you however are one who looks to seperate them selves from the pack by jumpin on another in a negative light, while at the same time not giving any constructive information your self!..if your not looking for help..or are offering help..then dont post..take your negativity back to prostreet or that dushbag forum for honda's and good riddens...at nicco..we are different bud...good luck to ya.,

[liquid_cool]

MSD's in any car are a waste of money and unreliable. (Unless its a balls out drag car and they carry spares because the things flake out all the time) Do a leak down test. I dont like the idea of you advancing your timing, you could have done damage to hard parts in the engine. I would also put regular plugs in the car, all that fancy crap is basically useless.

where do they all come from?..msd a wase of money and un reliable?..now your slingin missinformation...MSD ingnition systems are race proven!..fact is a fact...if you look at 99% of race cars..they run a msd system or a similar system for a reason...you really shouldent post sumpin like this becouse you may have a bias against them..its obvious you dont use one or you have used one where you installed it wrong to get that bias....with that said..

they are provin to give a better idle..proven to work..proven power gains..since his issue was at idle..and not at mid and wot..i recomended the 6A system..you should look into it your self and educate your self on how they work so you can provide acurate information on the forums about them.good luck

[Ka24de240sxS13]

hmm well all this arguing and my car still doesn't run right lol. the spark plugs are fine, they are NGK which are designed for imports and most the people i know run NGk. the leakdown test and compression tests are both good ideas and i am planning to do it as soon as i can get a hold of the equipment. and my KA isn't a hunk of trash, if you would have read my first statement, it was rebuilt only a year ago. its not an old stock motor. and as far as the msd ignition system goes, im sure it would benefit my performance, but it wouldn't be substantial enough for me to fork out the money to buy it. I do agree that a turbo would be exactly what i need as far as performance, but how can i be comfortable installing that if my car doesn't run correctly as it is now.

[1KleenS13]

where do they all come from?..msd a wase of money and un reliable?..now your slingin missinformation...MSD ingnition systems are race proven!..fact is a fact...if you look at 99% of race cars..they run a msd system or a similar system for a reason...you really shouldent post sumpin like this becouse you may have a bias against them..its obvious you dont use one or you have used one where you installed it wrong to get that bias....with that said..

they are provin to give a better idle..proven to work..proven power gains..since his issue was at idle..and not at mid and wot..i recomended the 6A system..you should look into it your self and educate your self on how they work so you can provide acurate information on the forums about them.good luck

Are you a spokesman for MSD, or do you just read magazines? Riddle me this Batman, why do NASCARS have two of them in the car? Maybe because they flake out and have to go to a backup ign box. My dads car had a MSD box on it and the thing ran like junk, UNTIL he went back to a STOCK system. I know of a guy in florida Cal Hartline that has a ton of broken MSD boxes laying in his shop. I had one for my Buick but I got rid of it. So yeah I am talking from experience. They only produce multiple sparks under 3K, and if you have any clue about Spark KV and burn time the MSD's are junk. It you have a high Spark KV you wont have a long burn time. You can change that with your spark plug gap for crying out loud. (but I guess you already knew that). Bottom line is MSD is not needed on the OP's car. You cant just start throwing money at things and hope it will fix the problem. Oh BTW Its called Hydrolocking when coolant gets into the cylinders NOT Vapor Lock.

OP I appoligize for the arguing, but some people think that buying the biggest ignition system, fuel pump, injectors will solve all your problems. Again I really am sorry for turning your problem into a pissing contest.

Now lets try to solve the problem. First you need to set your timing to factory specs. Also you really need do the LEAKDOWN TEST, this test will tell you if anything is blowing by the rings, headgasket or valves. Also did the engine run slow from the begining? I would verify that the cams setup correctly. Also is #3 the only one that misfires? That would indicate there is a problem with #3 cyl only. You need fuel, air, spark, compression to make an engine run. You could have a crappy fuel injector thats partially clogged? Do you have a K&N air cleaner or and filter that has a coating of oil on it? If yes try cleaning the MAF with MAF cleaner, over time that oil coats the element and will make the car run crappy. Make sure your vac lines are in good condition too. And also notice I didnt mention once that you should buy anything for the car (except MAF cleaner). Also FWIW alot of factors affect a cars performance, if you have any dead weight in the car its obviously gonna slow it down.

[liquid_cool]

Are you a spokesman for MSD, or do you just read magazines? Riddle me this Batman, why do NASCARS have two of them in the car? Maybe because they flake out and have to go to a backup ign box. My dads car had a MSD box on it and the thing ran like junk, UNTIL he went back to a STOCK system. I know of a guy in florida Cal Hartline that has a ton of broken MSD boxes laying in his shop. I had one for my Buick but I got rid of it. So yeah I am talking from experience. They only produce multiple sparks under 3K, and if you have any clue about Spark KV and burn time the MSD's are junk. It you have a high Spark KV you wont have a long burn time. You can change that with your spark plug gap for crying out loud. (but I guess you already knew that). Bottom line is MSD is not needed on the OP's car. You cant just start throwing money at things and hope it will fix the problem. Oh BTW Its called Hydrolocking when coolant gets into the cylinders NOT Vapor Lock.

OP I appoligize for the arguing, but some people think that buying the biggest ignition system, fuel pump, injectors will solve all your problems. Again I really am sorry for turning your problem into a pissing contest.

Now lets try to solve the problem. First you need to set your timing to factory specs. Also you really need do the LEAKDOWN TEST, this test will tell you if anything is blowing by the rings, headgasket or valves. Also did the engine run slow from the begining? I would verify that the cams setup correctly. Also is #3 the only one that misfires? That would indicate there is a problem with #3 cyl only. You need fuel, air, spark, compression to make an engine run. You could have a crappy fuel injector thats partially clogged? Do you have a K&N air cleaner or and filter that has a coating of oil on it? If yes try cleaning the MAF with MAF cleaner, over time that oil coats the element and will make the car run crappy. Make sure your vac lines are in good condition too. And also notice I didnt mention once that you should buy anything for the car (except MAF cleaner). Also FWIW alot of factors affect a cars performance, if you have any dead weight in the car its obviously gonna slow it down.

wow man your incredible..your lookin for a fight..what ever..your dads car had one..nasca runs 2 ..what car you drive?ohh your dads..you are rite on the hydrolock thing..but we keep it as simple as posible...if ya wana forum battle thats cool..im down..so here is my first hit

#1. show us your car..like a pic with you workin on it..from your exstencive experience..not your dad's..with a pic of the title showing its actually yours..#2. show us these MSD boxes lying in ruin..you say your friend keeps a pile of them lying around that are junk..take a pic..lets see!..back up your bash.

now for mine... http://www.myspace.com/liquid_cool_ka24deim rite there..pics and all..feel free to look around..ohh..msd in there allso..im allso going to start a thread for MSD horror stories..lets see how many takers we get..

[1KleenS13]

Ok your 37 years old and you want to battle on the internet. Are you serious? I dont have to prove anything to you or anyone. Why do you want me to take pictures of me working on a car, next time just ask and i'll show you how to work on one. Seeing as I'm ASE certified and work on cars for a living I've learned a thing or two. I've learned that guessing and throwing parts at cars normally dont fix them. You also didnt answer any of my question, what gives?

And no I dont drive my dads car. So heres a quick recap...... You dont know what your talking about.......Your a Might Suddenly Die nutswinger......Your 37 and an internet warrior......And your 37 and cant spell worth a $hit. That pretty much sums it up. Oh I forgot your dash looks like garbage too .

Battle over.............you win my friend. You can tell all your friends how you "battled" this guy on the internet and "served" him. You win Liquid_Stool

OP if you want any advise from me just email me so we can cut out the arguing and get your car fixed. , I'm not going to post in this thread anymore. Good luck

[liquid_cool]

thats what i thought..when called out..your only responce is a personal attack..thats cool..wish ya luck man.....next time just give information..we all bring a piece of the puzzle to the table...there is never a need to be a dushbag and flame someone..you might just get called out..your lesson has been learned...keep posting constructivly and we will get along fine...but dont dare try to flame another member becouse they dint think of everything on a post..its hard enough to help others on limited information, thats why we all participate..to bring it all together...peace

[liquid_cool]

hmm well all this arguing and my car still doesn't run right lol. the spark plugs are fine, they are NGK which are designed for imports and most the people i know run NGk. the leakdown test and compression tests are both good ideas and i am planning to do it as soon as i can get a hold of the equipment. and my KA isn't a hunk of trash, if you would have read my first statement, it was rebuilt only a year ago. its not an old stock motor. and as far as the msd ignition system goes, im sure it would benefit my performance, but it wouldn't be substantial enough for me to fork out the money to buy it. I do agree that a turbo would be exactly what i need as far as performance, but how can i be comfortable installing that if my car doesn't run correctly as it is now.

sorry for the fight on your thread man..sometimes ya have to wade throu the crap to get to the meat of things...if your leakdown and comp test's are good..then its not a headgasket or valve issue..or rings...this has to be a timing issue then...are you shure your buddys are bone stock? and what grade of fuel are you running compared to them?..do they have other mods like lightend flywheel or aluminum drivelines?...are they using larger injectors?..just seems odd to me that they would be quicker than you if ya all are running stock..they must have mods to help there responce times over yours..ask them and get back to us.

[liquid_cool]

bump for update's

[Chingon]

alright so Ive had my s13 running with a rebuilt motor for about a year now and i have always had a lack of power. the car doesn't pull very hard compared to my friends 240sx which are both stock KA's. -my first fix was NGK iridium spark plugs, checked the resistance of the wires, and gap of the plugs. - I adjusted the timing to 20 degrees ahead. (after this i noticed that the car seemed to misfire randomly.) but it did pick up a little bit. -new air filter

so im confused as to what my next step should be. i want my car to run like its supposed to.

check compression, bad rebuilds usually start there. If 1 is low, or 2 are low but not together, rings are bad. If 2 or more are low and next to each other, and you see water vapor in your exhaust, it's a head gasket.

check codes.check injectors, clean injectorsgo get the fsm and go down the troubleshooting section in the Fuel and Emissions. There's just too much BS to trust much of what's been said on here, and I'm lacking the will to correct it.

[liquid_cool]

hmm well all this arguing and my car still doesn't run right lol. the spark plugs are fine, they are NGK which are designed for imports and most the people i know run NGk. the leakdown test and compression tests are both good ideas and i am planning to do it as soon as i can get a hold of the equipment. and my KA isn't a hunk of trash, if you would have read my first statement, it was rebuilt only a year ago. its not an old stock motor. and as far as the msd ignition system goes, im sure it would benefit my performance, but it wouldn't be substantial enough for me to fork out the money to buy it. I do agree that a turbo would be exactly what i need as far as performance, but how can i be comfortable installing that if my car doesn't run correctly as it is now.

if the leakdown and comp test prove good..the only thing i can think of is timing..are your cams alighned correctly?..if the intake and or exaust is off by 1 tooth it would couse simmilar symptoms ..its another avenue for you to look into.

[Ka24de240sxS13]

ran a compression test yesterday, here are my results1 cylinder - 1352 -1403 - 1404- 145

also i fiddled with the distributor timing a little bit with a timing light and experimented with different settings to see what would happen. at 0 degrees the car was so retarded that it died on the first run and had no power whatsoever. at 10 degrees the car stopped dieing but still had no power, the misfire was still there. i finally left it at 15 degrees because the misfire went away, and the power seemed to return.

[Chingon]

ran a compression test yesterday, here are my results1 cylinder - 1352 -1403 - 1404- 145

also i fiddled with the distributor timing a little bit with a timing light and experimented with different settings to see what would happen. at 0 degrees the car was so retarded that it died on the first run and had no power whatsoever. at 10 degrees the car stopped dieing but still had no power, the misfire was still there. i finally left it at 15 degrees because the misfire went away, and the power seemed to return.

Stock timing is 20 deg. btdc +- 1 or 2 degrees, so that makes sense.

Compression howto:http://www.240sx.org/faq/artic...t.htm

your number seem low, rings are gone. Follow directions on top and retest.

valve timing could be off too

[Ka24de240sxS13]

where do they all come from?..msd a wase of money and un reliable?..now your slingin missinformation...MSD ingnition systems are race proven!..fact is a fact...if you look at 99% of race cars..they run a msd system or a similar system for a reason...you really shouldent post sumpin like this becouse you may have a bias against them..its obvious you dont use one or you have used one where you installed it wrong to get that bias....with that said..

they are provin to give a better idle..proven to work..proven power gains..since his issue was at idle..and not at mid and wot..i recomended the 6A system..you should look into it your self and educate your self on how they work so you can provide acurate information on the forums about them.good luck

Ha and see that's the funny thing is that I actually DO have a lightweight flywheel, and a sixpuck clutch, and they ARE running bone stock. and yet my car pulls crap compared to theirs.

But i was considering valve timing... a while back i tried swapping in an exhaust cam on the intake side for the high end gains, but i fail miserably. so i swapped my intake cam back in, but it took me a couple of tries. So i think im gonna try to reset the valve timing again.

You say you have 20 years of experience rebuilding motors? do you or anyone else have some instructions on how to set the timing from the middle gear where the chains meet, up to the cams? i know about the markings on the chain and on the gears, but how do you go about doing it without making the chain too tight on one side, and too loose on the other, or just failing in general. lol could someone just give me instructions on how they would go about doing this?

[liquid_cool]

this part is easy..follow these instructions to the letter...

#1. remove the spark plugs..all of em..makes turning the motor by hand easyer..remove the valve cover and front timing cover with dizzy.#2. wadd up a piece of plastic or a napkin...put it slightly down the #1 spark plug hole...#3. bump the starter over..not turn over..but slightly bump till the plastic or paper goes flying out...that will signal your on the compretion stroke and close to Top Dead Center..or tdc....now look at your marks and line up the tdc mark with the pin by the crank...#4. Once you have the crank at TDC..now you will be able to judge cam alighnment...the #1 cylinder cam lobes should be facing away from eachother at a SLIGHT upward angle.... (here is a tip to know if your off by 1 tooth ither way)A.) if your intake cam is to far advanced by one or more teeth: you will notice a bogging sound and possible back fires throu the intake.

B.)if your intake cam is fine..but your exauhst cam is to far advanced by one or more teeth: your engine will run..but have little or no power or excelleration..

those are the most common errors when setting the ka24de's cam alighnment....if you have any of those symptoms..make marks on the chain and cam with permanant marker and rotate just the sproket needed to get it in the rite place..you may need a friend to help you rotate the cam back allso while you hold the chain in place...

Once you have the cams where you want em then you are ready to set up the dizzy....

the #1. cylinder firing position is excatly on the left side of the plastic area for the harness plug, rite where it meats the metal..keep that in mind...once your front cover is replaced (make shure you put the chain tentioners back on..lol before this step)....rotate the motor to the last timing mark to the rite side of the marks..thats 20 degree's befor Top Dead Center..its important..that your presice on that..the rest is easy....

Now you will need to rotate the dizzy from the #1. fireing position counter clockwise 1/4 turn..slowly insert the dizzy into the hole...the rotor should start to turn..at this pint you should be able to tell if your close to the #1. position..if so..compleate the install by using the cap and a place to push it in or palm it in if its dificult....replace all the plugs and wires and valve cover..give her a test start..ajust idle to your liking ..ither by the idle air controll valve..or by the set screw under the throttle..

thats the simple way in a nutshell...you may have to reajust the cam position a few times to get it correct...the chains do have some slack that is taken in by the tentioners under load from the oil pump...and thats probly what was throwin ya off..good luck bro..let me know if ya need more help on this.

[Ka24de240sxS13]

this part is easy..follow these instructions to the letter...

#1. remove the spark plugs..all of em..makes turning the motor by hand easyer..remove the valve cover and front timing cover with dizzy.#2. wadd up a piece of plastic or a napkin...put it slightly down the #1 spark plug hole...#3. bump the starter over..not turn over..but slightly bump till the plastic or paper goes flying out...that will signal your on the compretion stroke and close to Top Dead Center..or tdc....now look at your marks and line up the tdc mark with the pin by the crank...#4. Once you have the crank at TDC..now you will be able to judge cam alighnment...the #1 cylinder cam lobes should be facing away from eachother at a SLIGHT upward angle.... (here is a tip to know if your off by 1 tooth ither way)A.) if your intake cam is to far advanced by one or more teeth: you will notice a bogging sound and possible back fires throu the intake.

B.)if your intake cam is fine..but your exauhst cam is to far advanced by one or more teeth: your engine will run..but have little or no power or excelleration..

those are the most common errors when setting the ka24de's cam alighnment....if you have any of those symptoms..make marks on the chain and cam with permanant marker and rotate just the sproket needed to get it in the rite place..you may need a friend to help you rotate the cam back allso while you hold the chain in place...

Once you have the cams where you want em then you are ready to set up the dizzy....

the #1. cylinder firing position is excatly on the left side of the plastic area for the harness plug, rite where it meats the metal..keep that in mind...once your front cover is replaced (make shure you put the chain tentioners back on..lol before this step)....rotate the motor to the last timing mark to the rite side of the marks..thats 20 degree's befor Top Dead Center..its important..that your presice on that..the rest is easy....

Now you will need to rotate the dizzy from the #1. fireing position counter clockwise 1/4 turn..slowly insert the dizzy into the hole...the rotor should start to turn..at this pint you should be able to tell if your close to the #1. position..if so..compleate the install by using the cap and a place to push it in or palm it in if its dificult....replace all the plugs and wires and valve cover..give her a test start..ajust idle to your liking ..ither by the idle air controll valve..or by the set screw under the throttle..

thats the simple way in a nutshell...you may have to reajust the cam position a few times to get it correct...the chains do have some slack that is taken in by the tentioners under load from the oil pump...and thats probly what was throwin ya off..good luck bro..let me know if ya need more help on this.

Thanks a lot man for taking the time to explain that, i really appreciate it. your a really cool guy

I will try it out and let you know if i have any issues.

[Vegascorbin]

Stock timing is 20 deg. btdc +- 1 or 2 degrees, so that makes sense.

BE CARFULL WITH THAT STATMENT!

SOHC Stock Timing is 15º

DOHC Stock Timing is 20º

Note: "Stock"

[liquid_cool]

vegascorbin is correct..STOCK timing for a ka24de is 20 btdc...some tuners change this for the mods they have with custom hardware...dont get confused ..just keep it the stock timing.

[Ka24de240sxS13]

Alright so here is my update so far:

I checked the valve timing last night, and everything seemed perfect. 6 links between the top marks, and the lobes were facing outwards at TDC.

Btw, the lack of power was due to me setting the distributor timing to TDC (second line from the left on the crank pully) instead of BTDC (last on the right). The power i was lacking is definitely there now

But today, i hooked the car to a sun machine and some funny stuff showed up. There was no spark pattern, and the spark line didn't read 3K or higher like its supposed to. instead it showed NEGATIVE, my plugs are firing on negative polarity?? But at least now we know that the missfire is directly related to the ignition system somehow.

very confused... any input guys?

[liquid_cool]

i have no clue what a sun machine is..but im assuming its a form of engine diagnostic machine...with that said....some systems are triggerd by grounds..and not power..like your injectors for instance..they have a constant hot..but get triggerd by the negative side of the system...i read up a bit in the FSM i have..and it dosent mention anything about the WHOLE car running on the negative side.....i think..the best people to ask on this one would be a factory service guy at a dealer..they can shed some light on things...good luck

[Ka24de240sxS13]

i have no clue what a sun machine is..but im assuming its a form of engine diagnostic machine...with that said....some systems are triggerd by grounds..and not power..like your injectors for instance..they have a constant hot..but get triggerd by the negative side of the system...i read up a bit in the FSM i have..and it dosent mention anything about the WHOLE car running on the negative side.....i think..the best people to ask on this one would be a factory service guy at a dealer..they can shed some light on things...good luck

Sun Machine = engine diagnostics/emissions etc...The WHOLE car is not running negative, its not a VDub lol. its just what the spark pattern is showing. think of it as a heart beat on a monitor.

Here is an example: (the FIRST line shows up as negative 2K on MY results. and the rest doesn't show up correctly like its supposed to on this pic)

So what goes wrong commonly on 240's ignition system's that would cause it to fire out of whack? with no positive firepower, even going into the negatives to fire?