soxbaseball

My 87 trans am GTA 305 TPI will run a while then start to spit and sputter then eventually shuts off. It doesnt do it at a specific temp, time or miles. Its just random. I let the car sit for an hour or two and it starts right up and drives fine. I have replaced the fuel pump, distributor, ignition coil, fuel pressure regulator, fuel filter and im running out of ideas. Every time I think I finally fixed it im back to sitting on the side of the road waiting for it to cool back down.

camaronewbie

Did you replace the entire distributor, or just the cap/rotor? I ask because this sounds like an ignition control module issue - but there should have been a new one within the entire new distributor.

8T9Formula

iTrader: (1)

Also check your injector coil resistance. Factory injectors should have no less than 10 ohms but they are generally around 16 ohms when good. Heat affects them and their resistance can decrease when they heat soak while driving. The reduced resistance while hot can give stalling, rough idle, hard or no re-start conditions until they cool off.

ninetyone

iTrader: (2)

heat also will effect the ignition control module,but i am gonna guess u have a bad injector.

soxbaseball

Should I check them when the engine is hot?

soxbaseball

And yes I replaced the whole distributor

ninetyone

iTrader: (2)

doesn't matter

soxbaseball

Ok I checked them while the engine was cold and got 15 and 16. I'm going to let out get hot then check it again and see what I get

jjlabinski

I vote for control module.
If you have the remote style coil the distributor for this set up does not contain the electronics.

transam_53

did you check it when it was hot? would like to know if you found the problem I have the same thing happening...

soxbaseball

I let it get to normal operating temperature and it didn't change.

soxbaseball

What control module are you referring to? My ignition coil is separate from the distributor.

transam_53

I think hes talking about the ignition control module inside the distributor, which is below the rotor.sometimes its bad even if its new,,.that is what I am thinking is my problem,, or the injectors...

formulax4

iTrader: (1)

Must determine if its losing spark or fuel when it wont start.So the time period where it wont start is a great time to trace down the problem.First try pulling a sparkplug wire during the no/start condition. If it indeed does have spark next try a little ether or gas in a squirt bottle down the tb and see if it starts.(fuel pressure gauge is best).If its spark then go from there and diag the ignition system,If its fuel does the fuel pump relay engage the pump after 15-30 seconds key on off cycle?

transam_53

mine has spark if I spray a little fuel into the tb it starts but not enough to keep it running long... but I hear the pump also,, and sometimes when this happens the ecm shuts down and thats why it wont start even with fuel or quick start..

soxbaseball

Mine runs just really rough and has no power. How would I check the module to
know if it was bad

formulax4

iTrader: (1)

You can remove the module and take it to a local parts store,most have the equipment to test the module.I would also recommend checking the resistance of the pickup coil as well.

Does the engine light come on just as its running like crap?

ninetyone

iTrader: (2)

something wrong with distributor or a bad ecm.

soxbaseball

What should the resistance be on the pickup coil

soxbaseball

My engine light stats on do to me not having the Caracol canister hooked up

TTOP350

iTrader: (8)

Guys do yourselves a favor and get a HELM GM sevice manual.
It will save you money time and all this guessing.
Its worth every penny
Oh i'm not trying to be a smartazz either!
now get out to the garage and get em running !

formulax4

iTrader: (1)

pickup coil 500-1500 ohms

https://www.thirdgen.org/forums/tech...-gone-bad.html


You can retrieve codes from the ecm by simply inserting a jumper in the aldl connector.Youll just have to research how to do it.It will flash the code by blinking the check engine light.Count the blinks,should be two digits,when you can see that it flashes a 12 at the beginning your ready to take note of your codes.Parts stores can also pull your codes for free.

soxbaseball

How would it b e the ecm when it doesnt do it all the time.

gta_knight

im having a similar problem with my 87 GTA with a 305 TPI too, it was running totally fine, ive not long put it back on the road after fitting hooker headers and a stainless exhaust. It started to misfire a little bit when driving, now its misfiring all the time once its in gear, it idles nicely when its in park but if i drive it its sputtering and it sometimes cuts out when i stop at a junction so i have to keep popping it in neutral to keep the revs up.

ive got a new module on the way, hopefully its just that, i was told they are prone to failing under heat, and with the headers on now theres more heat in the engine bay for sure, my leads, plugs, dizzy cap and rotor are all brand new too. so if the new module doesnt cure the problem i guess i will have to look at the injectors.

ive got no starting issues though, it started jolting coming down the motorway, so i thought id put my foot down to cure the problem, but thats when it felt like it was running on 2 cylinders ! really bad, so i pulled over to the hard shoulder, turned the engine off, i left it for maybe 40 seconds, then it started up straight away and run totally fine, i got all the way home and it cut out before i had a chance to put it on park !

ninetyone

iTrader: (2)

with headers ,your spark plug wires are easily burned or damaged from heat

ninetyone

iTrader: (2)

I second that one too. Also, double check your plug wires. I had a misfire within two weeks of installing my headers. The number 8 wire had damage from heat.

gta_knight

I got some Accel 8mm superstock wires after putting the headers on as i knew that was gonna be a problem, they've got the 90 degree boots and ive got them away from the headers as much as possible, i did check them too and they look fine, no discolouration or anything.