1992 Chevy Suburban starts but wont run! Was running fine.

[ndbrownknives]

Ok so here goes. I have a 92 Chevy 1/2 ton 4x4 w/ 350 TBI. A few days ago I started it and it was idling in the driveway. I threw a car seat in the back and slammed the back door and the the truck died. I couldn't get it to start again after that. The door slam could be total coincidence but, I thought it may have jarred something loose.
Here is what I have checked so far. First thing I made sure I have fuel, tanks is 3/4 full, fuel pump (6 months old) is running with key on (I can hear it and removed an access panel and can feel it vibrating like normal), replaced fuel filter, rebuilt fuel pressure regulator, checked the throttle position sensor, and replaced Idle air controll valve. After all of this I can start the truck but it dies right away. If i hold the throttle open I can get it to run for a few seconds(feathering the throtle) but it runs like crap. Plugs are new, wires are new, and I have good spark.
Prior to this issue I have no problems starting the truck with just a turn of the key and it was running great. If anyone has any ideas they would be greatly appriciated as I cant afford to just swap parts out.
Thanks for the help.

[tommie]

when i first read your post, i thought fuel pump....

(but you said you just replaced it, wish gm made it easier to check fuel pressure on the tbi's)

what brand of fuel pump did you use? was it an ac delco?

do you have any codes?

you might have to check the fuel pressure....


other than that i would check the coolant temp sensor on the intake manifold... search the user name chevy tech on here, he has posted the ohm vs temp values for that a few times....

[ndbrownknives]

Thanks Tommie,
I believe it was an Airtex. I got it from Autozone. As for codes, My check engine light is working but not on once it starts. I have not tried to pull codes though.
And as for the coolant temp sensor (just for my knowledge) how would it keep it from running? What would happen if I pulled the plug from the temp sensor while it was running?

Thanks again

[tommie]

on the coolant temp sensors that i have had experience with going bad, they were usually making the computer think the engine was too cold, and the computer was feeding the engine too much fuel.....

have you taken the air cleaner off to watch the injector spray pattern when you are trying to crank the engine? or when it is running?

i have done this before and have seen a very rich spray pattern before (coolant temp sensor)

what do the spark plugs look like? do they look like they are fuel fouled? or are they clean?

sometimes these things are hard to diagnose over the internet.... the best bet would be to check the fuel pressure and report back (search, but it is hard, and you need an adapter to make it work)

i would also search and find posts from chevy tech about checking the coolant temp sensor with an ohm meter, and report back on that also...

another thing to check would be for proper spark...... what you are describing could be cause from a weak ignition coil also....

these things are easier to diagnose in person...than over the internet....

[tommie]

also if you disconnect the coolant temp sensor (next to the thermostat housing) when the engine is running, the computer will set a code and use a failsafe value that is stored in the ecm....

[J-BABS]

i would check for vacuum leaks at hoses and intake, check distributor cap. when you replaced your fuel filter, did you run the pump and flush out the fuel line while the line was open and filter removed? when i replaced mine in my 89 gmc i flushed the open line and some particles flushed out. also (not to sound like a stupid question, but) did you install the filter in the right direction? years ago i had a 78 monte carlo that was running great and one day it just kept staling, truns out it was just a fuel filter.

[Unkle Fester]

My '98 Sierra had a similar issue, after tracking down and testing every underhood electronic component Someone told me to replace the Cap and Rotor. I couldn't believe it would be that simple, I just replaced it 3 weeks before doing a tune up. A tow truck ride and $250 later I got the truck back from the shop.

Guess what they did? They replaced the cap. Seems the caps sometimes form hairline cracks and causes cross arcs, effectively shutting the system down. Sounds to me like the door slamming may have pushed a faulty cap over the edge.

Or shook a connector loose somewhere... Yeesh.

I would recommend looking at the simple things before spending lots of time and money on other potential issues.

Just my 2 cents.