loganbonlender

hello, I am very new to the 350 tpi motor and was wondering if I could get some help here. I have a 91 trans am gta 350 tpi that won't start. was driving down the road and it started sputtering and died on the spot, after sitting there for 30 minutes it decided to start again and I limped it home for it to never start again in my garage. I have spark, I have fuel pressure, my injectors have 0 volts while cranking tho. I checked the fuses and they are all good. and are reading 12 volts while cranking. any ideas or suggestions would be helpful. thank you. it also will start on starting fluid for a second and die out again

JoeMonte

Fuel pump?

loganbonlender

I can hear it turn on and I have fuel in the rail, I was going to start looking at the relay maybe?

JoeMonte

That was my second guess. Must be an electrical issue if you aren't getting any volts at injectors. Follow the circuit back until you find where you do have voltage and figure out the issue from there.

loganbonlender

I'll take a look at it tomorrow, I'll keep you informed, thanks!

zed-028

Partially clogged car or exhaust could cause it. had this happen on me a while back, paint in the a$$ to track down.

zed-028

ever figure this one out?

loganbonlender

I have fuel pressure, I have spark, I hooked a test light up to each injector and they all light up, it sounds like it wants to start but just won't pop over, It just backfired very loud so I'm currently inside trying to regain my hearing

mcgarnicle

iTrader: (14)

Well a backfire is a sign that you are getting everything you need to make fire, but it is out of time. Distributor loose?

Rpicard21

Pump could be weak it needs at least 50 lbs I think check what your car needs mine is an 87 and it needs 50 ish or it won't run . Could also be something as simple as a bad ground

Rpicard21

Yes a plugged Cat will cause this also look and see if your cat is dented if so odds are it's plugged almost solid

loganbonlender

it has a hooker y pipe, so no cats. and with key on engine off the pump primes 30 psi and when it's cranking it's around 45, does that sound low?

Rpicard21

No it sounds bang on for a stock TPI mine has an aftermarket fuel regulator and special fuel injectors and I think I was wrong I think I have to have at least 40 to run but cranking is lower than that I think mynpump only delivers 65 so you should be good , could your Mass be damaged or one of the wires be off or frayed

loganbonlender

if there is no visible damage is there a way I can test it?

Rpicard21

This is going to sound bad but how many miles on engine and this is a LT1 engine rite ? If so I have seen the timing system screw up badly the shaft that drives the distributor slips or snaps or the timing chain itself slips jumped some teeth .

Rpicard21

If it's a 91 it is a regular TPI I still think either chain issue or this would be better your rotor in your distributor broke loose or the pick up came loose check that first pop the top off the distributor and have a look for broken parts

loganbonlender

350 tpi, it has 160k on it. it ran strong untill this day, like I said it died once in my drive way, I let it sit for a hour or 2. and it started right but up just to leave my stranded down a back road and it hasn't started since

loganbonlender

I actually just replaced the cap and rotor because I figured that was the problem because the cap and pick up were corroded, still nothing

TylerSteez

iTrader: (3)

sounds like a timing issue but its odd that it would randomly happen after being fine.

does anyone know if timing chains actually jump teeth once they wear out and stretch?

loganbonlender

I feel like if the timing chain advanced or retarded it wouldn't start again. once it died it started again, but it hasn't ran since

Rpicard21

It can run if the chain slips often when an engine is hot it will run with a sloped chain but it will run poorly once the engine cools down it will not run anymore . But you are probably rite

zed-028

mine wasnt the cat that was blocked, it wound up being the rear muffler full of about 5kg of fine black soot. didnt block it completely but enough to cause it to die. from there the plugs fouled up and it had no chance.

this still sounds exhaustish to me. drop the pipe somewhere before the rear muffler, clean the plugs and try to start it on fluid first

wear ear protection lol

redneckjoe

have you tried replacing the fuel filter? they're cheap and easy to change. it's possible that its partially clogged. you might have some fuel pressure but no flow.

loganbonlender

fuel filter was also replaced when I did the cap and rotor last week in order to try to get it to start. I'll look into the muffler tonight. hopefully that's it. I can't think of anything else it would be

scoflaw

iTrader: (2)

Injectors work on a ground signal from the ecm. Power alone doesn't make them work. You can make a noid light with an 1156 bulb and solder on a couple of wires.

loganbonlender

what would cause the ecm to cut ground?

scoflaw

iTrader: (2)

circuit board in ecm, bad wire or connection. Just happened to me, bad board. those ecm
s are cheap enough.

loganbonlender

I'm debating looking into it any further, I just pulled it up to my shop for the winter. currently in the process of building a carbed 383 stroker to drop into it over the winter. would be nice to hear it run one last time but I don't want to put much money into a motor I'll be pulling..

scoflaw

iTrader: (2)

You might as well figure it out or the problem could very well move to the next engine.

OK just read the carbed part. Your call then

loganbonlender

that's what I'm afraid of, I'll take a look at the ecm. thank you very much

loganbonlender

ecm was shot, starts right up now, thanks everyone!