SR20 DRIVING ME FREEKING NUTS!!!!!!!!!!!

Post by **dj_lennon_franz** » Sat Jul 02, 2005 4:31 pm

ok...heres the deal...i swapped my SR to a new chassis back in feb...since then the motor has gotten worse and worse and worse and worse...gas millage is total crap right now (im getting about 7 miles to the gallon)...car is stuttering when it accelerates (due to misfiring somewhere...or being loaded down with gas)....it back fires when revved up to aroun 6-7k rpms

ive gone thru and replaced:MAFS02 SENSORREWIRED THE MAFS COMPLETELY (nothing changed)FUEL FILTERSPARK PLUGS (properly gapped)CYLINDER COMPRESSION 132-135 ON ALL 4 (compression tested when cold..ideal cold compression)PISTONS ARE CLEAN (checked when changing spark plugs)FUEL PUMPTIMING SET 15 DEG BTDC (according to S14 service manual)

so im stuck...ive checked all my vacuum lines (this wouldnt affect acceleration...just the way the car boosts)...ive checked the intercooler piping (everything is nice and tight)...02 sensor was working when pulled from a friends car (he upgraded to a blacktop 02 and upgraded 02 housing)...when my smog was done i was told i have a large number of hydrocarbons emiting when accelerating (which means gas is passing thru un burned)

im about fed up and totally frustrated...like i said its just gotten worse and worse over the period since feb...so anyone wanna offer some suggestions cause im at wits end

Post by **srpowered240sx** » Sat Jul 02, 2005 6:11 pm

i had the same kind of issues with my redtop. check your ground wire coming off the coil pack wire harness. and check the plugs on each of your coil packs. id also try trading coils with the friend you got the 02 sensor from. just keep troubleshooting. fuel pressure regulator and a gauge wouldnt hurt. if its something that has progressively gotten worse check all your harnesses, things that could be melting. under a load mine would miss and backfire. good luck, keep us posted.

Post by **BaliLover** » Sat Jul 02, 2005 6:46 pm

I had a similar problem in a BMW with coilpacks. After MONTHS of playing with it, I finally found it to be the extensions on the coilpacks, that connect to the plugs (boots that go into the head). They were dryrotting and cracked, and were arcing inside the head.

Post by **dj_lennon_franz** » Sat Jul 02, 2005 7:10 pm

im leaning more twords the engine coolant temp sensor...going to be replacing it in the morning...my coilpacks are fine (all sparking A-OK)...my FPR is fine (not a common part to die on SRs)...i would be able to tell from the spark plugs i pulled if a coilpack was burning out...and a bad coil pack would NOT constatute to the engine running pig rich

again ive got my money on the engine coolant temp sensor...when they malfunction...the fuel maps get all fuked up...the engine doesnt know how to correct fuel patterns at different temperatues so it constantly runs rich

well see in the morning

Post by **dj_lennon_franz** » Sat Jul 02, 2005 8:00 pm

ok...well nevermind...i tried a new coolant temp sensor...THAT DIDNT WORK...a friend is coming over in a few min and im gonna try out his coilpacks...well see if THATS the problem

Post by **dj_lennon_franz** » Sat Jul 02, 2005 10:30 pm

welp...once again...NOT THE COILPACKS...this is REALLY pissing me off

Post by **Nismo_Freak** » Sat Jul 02, 2005 11:51 pm

Try replacing injectors 0-rings.

If you are certain the TPS, ignition, and MAF are absolutely sound then it's a mechanical issue or an ECU issue.

Post by **f150intally** » Sun Jul 03, 2005 8:45 am

sounds like some injectors are stuck open to me. Have you tried checking out the injectors?

Post by **dj_lennon_franz** » Sun Jul 03, 2005 6:50 pm

no...havent tried the injectors...didnt exactly wanna get into that...but looks like im prolly gonna have to

Post by **scottsnissan** » Mon Jul 04, 2005 3:33 am

i ahd the same prob sorta/.I tried every thing u did no results.I finaly checked for boost leak on smic.Adn well that was it.Couldent see the leak but was there.We tested by pouring a gas/brake cleaner mix into it.Gas because it will evap after a while.As we poured it in it came out jus as fast.Replaced that and all good now.

So test for boost leak.Any size will hurt you.

Post by **kickertu** » Mon Jul 04, 2005 10:01 am

since tihs friend is a-ok with you switching things around, switch fuel rails.

i have money on a stuck injector, or bad o-rings.

you are running too rich.. get a wideband, and see how rich. if its in the 9:1 area all the time, the car is in safe mode.. check the ecu for codes as well.aim me for more questions

aim- kickertu

Post by **Teamsprock** » Tue Jul 05, 2005 6:06 am

Did you use a timing light? If not my guess would be timing. If you just stab it and go it can still be off. When I have just stabbed it and then checked it with the timing light its been off by as many as 10 degrees! If not that then are all the spark plugs black! What mods/management? If its a leaky injector or o-ring it usually won't be in all cylinders!

Post by **getnrowdy23** » Tue Jul 05, 2005 11:25 am

might just be a bad ecu... swap it if you can haha let us know

Post by **dj_lennon_franz** » Tue Jul 05, 2005 7:08 pm

new update:

the car is running DANGEROUSLY LEAN!!!! got a hold of a wideband kit and ran it on the car for a bit...the motor is running stupid lean...and at certain points off throttle the engine simply pisses out gas for a small amount of time then immediatly goes back to lean...thats where the bad gas millage is coming from...so since im running on a nice 14 year old fuel pump...i believe its time to ONCE AGAIN buy ANOTHER fuel pump...and this time it will be a DENSO!!!!!

no its not the ECU...ive already tried a different one from a car that runs fine...was one of the FIRST things i tried

Post by **dj_lennon_franz** » Tue Jul 05, 2005 7:09 pm

also the wide band was reading 16-19 the whole time

Post by **Nismo_Freak** » Tue Jul 05, 2005 7:43 pm

dj_lennon_franz wrote:also the wide band was reading 16-19 the whole time

Make sure you didn't have an exhaust leak before the wideband.

And off throttle you will see really lean A/F's, under partial throttle you will see lean A/F's, under WOT you should be below 12:1

Post by **dj_lennon_franz** » Tue Jul 05, 2005 8:13 pm

we tried 3 passes...all of the included above (partial...mid...and WOT) it never dipped below 16

Post by **S14-NEO** » Fri Jul 08, 2005 5:22 am

check your voltage on the MAF....i had a similar problem with mine on the dyno while tuning...it would not add any fuel...it may not be a wiring problem..might be an internal failure inthe MAF...try another MAF..maybe one of your friend will yank one off their car and let you try in on yours

Post by **dj_lennon_franz** » Fri Jul 08, 2005 10:04 am

its not a MAFS related problem

new FPR is on the way...will know more after that arrives

Post by **ergodyne5** » Sun Jul 10, 2005 2:16 pm

By any chance , are you running an open atmosphere blow off valve?

Post by **Cyberkreig** » Sun Jul 10, 2005 2:33 pm

F-P-R

Anyone?

Post by **Teamsprock** » Mon Jul 11, 2005 8:51 am

Try and pinch the fuel return hose, see if you feel pressure and if the idle changes(wrap with cloth and use plyers as per FSM), if so it could be the FPR. Do you have access to a fuel pressure gauge, that would be a very good investment if you don't, that way you know if its low pressure your chasing. If the pressure is low also check the hard lines and make sure they didn't somehow get pinched or are leaking, where is the fuel going if your getting a lean condition and bad gas mileage? I guess there is lots of things but you should find out what the Fuel pressure is so you can rule that as the problem or not! Also check the timing with a timing light.

SR20 DRIVING ME FREEKING NUTS!!!!!!!!!!!

SR20 DRIVING ME FREEKING NUTS!!!!!!!!!!!

Re: SR20 DRIVING ME FREEKING NUTS!!!!!!!!!!! (dj_lennon_franz)

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Re: (kickertu)

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