no start

[satilla308]

ok ka24e engine was running now cranks but wont start. 40psi fuel pressure, yellowish spark. new plugs, wires, rotor cap and rotor. decent compression. tries to start but only kicks over a little while cranking. obd2 picked up map sensor intake air temp and fuel temp sensor. nothing else. maybe faulty distributor/coil/crank angle sensor? thanks

[sx moneypit]

Welcome to NICO! If it is getting spark but it is weak you could possibly have a bad coil. You also need to check to see if the injectors are firing. What type of vehicle do you have?

[satilla308]

its a 97 pickup xe. the injectors are firing and the timing chain doesnt have alot of slack in it either. just wanted a second opinion b4 i dumped cash into a dizzy. that theonly thing i could think of after doing alot of hunting and testing

[PapaSmurf2k3]

Yeah yellowish spark sounds a bit iffy to me...
That being said, it could also be timing (be it ignition or valve).

[satilla308]

put new dizzy let mechanic do it. still no start. there isnt any voltage going to obd2 i had to hot wire it to fuse block to get it to read. it turns over and sputters slightly until it seems like it puts enough gas into pistons to flood it b/c gas begins to come back thru the intake slightly. i checked engine timing with engine at tdc on comp stroke of #1 cyl. it checked out fine. the new dizzy is sparking strongly and it has good gasin tank... can a faulty ecm do this? or will there be no spark? (im abt to push this truck off into the ocean)

[PapaSmurf2k3]

Did you adjust your ignition timing after putting the new dizzy in?

[satilla308]

i tried advancing it and retarding it but nothing. if i take the fuel pump fuse out (so it doesnt flood it from trying to start it) it will spit and sputter but doesnt ever kick over more than 4 times by itself. when i put the fuse back in it will spit and sputter a little then just cranks over and over like its flooded. the engine control fuse blew several times and i continued replacing it till i found the wiring harness was shorted on the valve cover. i taped it up and it didnt blow anymore. while searching for clues i found a green black striped wire going to ecm connector that had blistered and bubbled insulation as if it had gotten really hot from a short. could that b from me replacing that fuse so many times or could the ecm be fried?

[sx moneypit]

Seeing that you replaced the fuse that many times and the wiring issue leads me to believe your ECM is toast.Does the check engine light illuminate when you turn the key on?

[satilla308]

no but if i straight wire the obd2 connector i get codes and when i clear/erase them and re-run the test it pulls up the same codes. where does the power wire for the obd2 connector come from?

[satilla308]

the cel wasnt on when it was running either. the truck was idling rough before it quit and wouldnt rev past abt 3k to 4k rpms. has sucky power too. but when it quit i checked the fuel presure and it was 15 and bled down instantly. i replaced pump and i have 40 psi now. right before it quit i adjusted the ignition timing by loosening the adjustment bolt and advanced it slightly and the truck idled great and reved great w/o popping or stalling. i switched it off and it hasnt started since....

[satilla308]

i think you nailed it sx moneypit. i stripped out the inside. carpet, seat and harnes covers and stripped off electrical tape off of the harness and that black w/ green trace wire has gotten so hot its naked. this wire splits and goes to ecm/ to the rear of the truck and has one that goes to motor compartment but the one going to the front isnt melted or anything. just the one going to the ecm and the rear but they join at a splice. any ideas on what this wire does? havent found it in the haynes yet

[sx moneypit]

The black/green wire is the sensor ground.It goes to pin #50 on the ECM.




-Ben

[satilla308]

ok i traced the melted sensor ground wire to the fuel tank. that was the only one that was melted. from the tank all the way to the ecm connector pin. from the splice that goes to engine sensors to the sensors are fine nothing melted there. the sensor ground is still grounded and the sensor power wire (pink) has 4.90v so idk where to go from here.

[sx moneypit]

I would take a good look at all your grounds.The fuel pump maybe trying to ground through the sensor ground.

[satilla308]

there was an engine that was cut i this ur right it was using that small wire as a ground and it fried the ecm. it smelled burnt when i opened it. my ecm is a mecm b131 cant seem to find another one. i found a mecm b130 out of an identical truck. everythings the same. itll work right?

[satilla308]

thats suppose to say an engine ground cut into

[sx moneypit]

Nissan only shows only 2 ECMs for your truck, one is for federal emissions and the other for California emissions.

[satilla308]

ok ecm didnt fix anything. @#$! but it was only 50 bucks. found my engine control fuse is blowing when key switch is turned on. did it several times and now its not blowing. so there is a bare wire somewhere on engine cuz itll blow and then i can turn the motor over several times and it wont blow for a while. ive already taped up the spot on rubbing on the valve cover. but not results. truck does have a 3 inch body lift but i cant find any bare wires... other than the fuel pump and relay what other mechanisms make an audible sound temporarily in the engine compartment when ignition switch is turned on??

[satilla308]

well... i finally made some progress. the wire running to the rear O2 sensor (that i didnt kno was there) had completely melted on the exhaust. 4 bare wires fused together.... just got dark so i quit for today. im working on soldering new wires in place. there was about 12 inches of naked wire. i found this by tracing wires that were in the engine control fuse circuit. at least my fuse isnt blowing but still not sure if ill ever get this truck to run again. thank you guys for helping me. hope i havent been too aggrivating

[sx moneypit]

Glad you are making progress,keep us posted!

[satilla308]

ok so i tested just about every sensor on the truck. nothing found that would cause a no start. i was cranking the engine for the millionth time when i noticed it started turning over quicker. oh $#&* i thought. so i did a compression test and got 30psi on the cyl1 and my stomach sunk. but then after testing all four they all read 30psi. after thinking i finally thought of mechanical timing. since it would be unlikely for all four pistons to be that low and still close to the same psi. after rolling the engine over and over with the valve cover off i could never get either of the bright links to match up to the tic mark on the cam sprocket. and i can move the crank pulley past the timing marks and back without moving the cam shaft at all... so without sounding stupid i guess i need a new chain kit?

[satilla308]

oh, the closest either of the bright links got to the tic mark was 3 teeth off... how many times should i have to roll it over to line up the marks in the same way as putting a new chain kit on?

[PapaSmurf2k3]

You'll probably end up rolling it for a REALLY long time before all the marks line up again... The gear ratios coupled with the different chain lengths almost guarantee that.

Can you put the crank at TDC and take a picture of your cams? We should be able to tell you if they are correct or not.

[satilla308]

both keys should be straight up right?

[PapaSmurf2k3]

Huh?

[satilla308]

when u put a new chain on the tic mark on the cam is at the right and the woodruff key is at a 90 degree to that tic mark which would mean its at the top of the shaft when installing a new chain. and the crankshafts woodruff key is at the top when installing a new chain (when everything is aligned for top dead center for pist 1) so im wondering no matter where the alignment links are in relation to the sprockets IF the engine is in correct timing and IF its at TDC for piston one on the compression stroke then wouldnt both woodruff keys still be pointing up or at the top of the shafts rather? haha im 19 and still adding on to what my father has taught me (former mechanic and round track racer). so if im not making any sense then dont be afraid to correct me. im flying solo on working on this truck for the first time...

[PapaSmurf2k3]

I wouldn't go by what's on the sprockets, go by what the cam lobes look like. TDC on cylinder 1 on the compression stroke, all valves should be closed.
Furthermore, the intake lobe (on cylinder 1) should be sort of between 9 and 10 o clock and the intake lobe should be between 2 and 3 o clock.

[satilla308]

installed new chain kit after getting home from college. got it together with no trouble at all. now when the lobes of the camshaft peaks and rolls over its smooth and tight. before when the lobes peaked over the cam shaft jumped forward under the pressure of the valve springs. lotta slack i kno. im finally feelin good about this truck again. now i got great compression in all four and will finish puttin it all back together tomorrow. any advice on putting the oil pump back in? i kno to line up the punch marks on oil pump shaft with engine on tdc but is that all there is to it? thanks for all of your help

[satilla308]

its finally running. played with the idle and its idling at about 800. it surges a little, only at idle tho and while driving it it shut off a couple of times while pressing the clutch and letting off the gas at 1500 or more rpms. when it doesnt shut off it will drop to about 500 rpms and climb back up to 800. still got a fuel temp sensor, air intake temp, and map/baro circuit code on my gst scanner. it has a crappy cone air filter. not the oem air cleaner. and have several exhaust leaks. so idk if i should look for a vacuum leak, focus on finding an oem air cleaner, or fix exhaust leak first. it drives great just small problem with the idle. any ideas?

[PapaSmurf2k3]

Yup I'd check for vacuum leaks and check your ignition timing too. Good to hear that its running!

Your idle air control valve could be all gummed up too.