i tried everything i can think of and the 305 tpi still runs rough - Third Generation F-Body Message Boards

liteumup387 · 09-23-2009, 08:28 PM

heres everything i know about it PLEASE HELP

i have a 88 camaro with a 305 tpi with MAF it has a pretty rough idle itll occasionally die while in gear, a hesatation getting off idle and a partial throttle miss its not a dead miss more like a stumble accelerating hard it feels fine
reving it up in the driveway it straight up died twice, died like i turnd the key off (different days couldnt make it do it again)

i spent days and a couple cans of brake clean looking for vaccume leaks and i cant find any more

timing is set

i changed plugs, cap rotor, and coil... i just had the module tested at autozone and it tested fine (i donno how accurate their tester is i know they didnt heat it up) wires look healthy and are not arking

the MAF wires were cut at one point i soderd them up and heat shrunk them

the knock sensor wire was cut i soderd that up heat shrinked it (could it be a bad or wrong knock sensor)

i know the o2 wires are cut and just twisted together with some electrical tape on them i dont know if the wires are crossed or anything i havent gotten back under the car to fix it the right way yet

also the smog pump and egr was removed

fuel pressure is good regulator bumps up psi when vac is disconnected i pulld the injectors and cleand them (they wernt too bad to start with)

my buddies telln me to throw a distributor at it does anyone have any idea on what it could be i am ready to put a for sale sign in the window and be done with it

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86irocu · 09-23-2009, 11:03 PM

did you set the timing in default mode? There is a Tan/White wire with a connector on the passenger side of the motor near the firewall. Did you disconnect this wire when you set the timing?

liteumup387 · 09-24-2009, 12:34 AM

yea i set the timing after i disconected the wire... i donno it seems this car runs better with the timing a little far advanced ive been trying to set it someware around 10 to 12 deg and it runs pretty bad i was messn around and itll keep gettn better if i keep adjusting it advanced till its about a half inch off the stock timing indiactor then it starts to fall off whats the timing supposd to be set at exactly maybe ill try setting it and disconnecting the bat for a while maybe the timing is just so jackd the computer just cant compinsate right away... i donno im willing to try anything at this point lol

86irocu · 09-24-2009, 08:06 PM

what do your spark plugs look like? are you sure you dont have a fuel issue?

transam85dudeman · 09-24-2009, 10:24 PM

THIRD GEN COST THE MOOLA, CHEDDER, LETTUCE. ive spent probably over a couple of grand if not more than what i paid originally. Theyre pretty fun considering theyll whoop rustangs, bmws, mercedes lower back sides. they handle awesome and are at least 50 percent cheaper to maintain than other cars on the road. Of coarse theres the dreaded troubleshooting.. anyways, the o2 sensor should be one wire i believe. (Whats your idle at? what about the idle in drive. will it stall if you press the brake and give a little gas while in drive? tell me you used the heat sink grease for the module when replacing? what about in park- does it rev and sound like a champ, but only in drive does it poop out? when under the load in drive the rpms come down.. when timing the beast did you adjust the idle? theres a long procedure to do so. sometimes there may not be a vacuum leak at connections but a vacuum leak with components instead, i picked up a hand vacuum pump a while back, found numerous leaks and bad checkvalves. but in your situation, was it stalling when you bought it? or just stalled one day out of the blue. try testing the spark, should be blue. and let me know if it runs great in park but not in drive.

*update, ok so i read your post a little better. it sound ignition coil to me, possible the maf, but it should idle at least without the maf, im thinking it either the pickup coil, or the ignition coil, theyre both distributor related. with a bad pickup coil the computer fires randomly. test the resistance of the components..and also test the volts of the tps (.555volts with key to on positions- give or take .04 volts) . peace and btw with the egr removed the computer needs to know that. chip wise

liteumup387 · 09-25-2009, 11:35 PM

thanks for the input guys ill try and work on it tomorrow and see what i come up with.... one more thing i donno if this changes any of your advice but i took the car to work today and it ran great for about 10 min then it just started going down hill from there?!? i donno but ill deffinatly check those sensors. how do you test a maf ill try and check that while im in there
once again i appreciate the input ill keep you posted

all4u · 09-26-2009, 09:25 AM

Ok, this is kind difficult to explain so hopefully you already know what I'm talking about. Test your fuel pressure on the valve on the fuel rail. Let the car idle till it warms up. Put it in reverse, the pressure will go down but does it die? If not idle back out of your driveway, put in neutral, give it a quick rev, let off gas, put in drive and try stomping on it. If it dies, or fuel pressure goes down a ton, it could be the fuel filter. Here's why, if a bunch of junk is stuck in the filter, when you turn off the car, it settles to the bottom of the filter. When you do my procedure, it kicks up the junk and clogs the filter, killing the engine.

What is the fuel pressure like in your car? TPI's are sensitive to fuel pressure. Do you have an adjustable regulator? If so, can you bring pressure up to 50 psi? If not, you could have a pump that is dying. If you pull the vacuum line off the regulator, (doesn't need to be adjustable) does the idle go up? Does fuel squirt out of the hole on the regulator? If it does, replace the regulator.

Hope this helps. Tell me your idle fuel pressure warmed up and what the fuel pressure is when you pull the vacuum line.

liteumup387 · 09-27-2009, 09:25 AM

hey guys i got it... taken your advice i did everything you guys told me to do and everything was fine....

(transam85) the last thing i checkd was the TPS the voltage was a little high so i adjusted that started the car and it was reving to 2000 rpm and if i touched the gas pedal it would die long story short he had the tps set at too low of a voltage and the idle was set too high

thanks for your help guys i couldnt believe it was something so simple that was making the car run so bad if it wasnt for you guys this problem would have cost me alot more money

thanks
john

transam85dudeman · 10-01-2009, 08:40 AM

did you get it? any engine code? i had a code 22 pop up on me two nights ago. my voltage output was too low (.4)on my tps. itd stubled while wot. anyways i changed it back to .55 and it was cool. you ought to try testing the resistance on the ignition coil, pickup coil and injectors. To test a maf sensor..slap it. any change in idle is a bad maf

*update. i just read you post. i assume you got it working. damn tps
! That makes both of us with low voltage. its from those awesome WOT wheelie stands.(jk), peace