96 Bravada injection problems, NEED HELP

[yekta]

Hi there, the car is 92[not 96 sorry] with the 4.3 vortec has 172k miles on it. Since the day I bought -2k miles ago approximately- it would take a while to start. If you turn the car off and than start it again when its warm it would just fire it up!

it died on my gf, had to get it towed to my place -alot of money - She said it suddenly stopped running. Changed the spark plugs, it started went 100ft then died on me again like it did on her. Then changed the electronic starter module or something like that which is attached to distrubutor -I had to remove the intake manifold for that- and it started running again. Then I added fuel booster, some fuel injection cleaner and stuff. Today while i was driving, gas was just coming on and off like it was hesitating. and then small explosion sounds coming from the engine not the exhaust. Its like something stuck in engine, can't breathe... So i let it idle in front of the house almost about 2 hours, finally it choked and died... I donno how to restart it but I am guessing its the stuff I added to the tank caused it, and it never blew out a black smoke.

Thanks in Advance

[MT-2500]

Originally Posted by yekta

Hi there, the car is 96 with the 4.3 vortec has 172k miles on it. Since the day I bought -2k miles ago approximately- it would take a while to start. If you turn the car off and than start it again when its warm it would just fire it up!

it died on my gf, had to get it towed to my place -alot of money - She said it suddenly stopped running. Changed the spark plugs, it started went 100ft then died on me again like it did on her. Then changed the electronic starter module or something like that which is attached to distrubutor -I had to remove the intake manifold for that- and it started running again. Then I added fuel booster, some fuel injection cleaner and stuff. Today while i was driving, gas was just coming on and off like it was hesitating. and then small explosion sounds coming from the engine not the exhaust. Its like something stuck in engine, can't breathe... So i let it idle in front of the house almost about 2 hours, finally it choked and died... I donno how to restart it but I am guessing its the stuff I added to the tank caused it, and it never blew out a black smoke.

Thanks in Advance

First check for good hot spark to all plugs then.
A fuel pressure check would be in order and watch gauge for a fast leak down.
Here is fuel pressure check guide lines
do as much as you can and post back result.

Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.

[yekta]

Originally Posted by yekta

small explosion sounds coming from the engine not the exhaust. Its like something stuck in engine, can't breathe...

I meant backfiring, but in that plastic air tube which goes to throttle body. So yeah I saw that plastic tube jumping!! and also smells funny, like somethings burning

Thank you for your repost! I will go on and try to read fuel pressures, but the car wouldn't start again after it died last night. What can I do to restart again? Last time i changed the spark plugs and/or changed the controller module it started, but it would start the same way it did before: hold my hand in the ignition for about 6 sec. and then fire it up

also O2 sensors has been changed when I bought them, so thats out of possibilities also

[1996LTOwner]

Change the distributor cap. My blazer shut down on me and when trying to start it, the engine would backfire and sometimes compression lock. After replacing the timing chain and not fixing it, I figured out that the distributor cap was shorting the center post (coil wire) and #4 plug since the two run so close together. Yours sounds as though it has more of an intermittant short.

[yekta]

Originally Posted by 1996LTOwner

Change the distributor cap. My blazer shut down on me and when trying to start it, the engine would backfire and sometimes compression lock. After replacing the timing chain and not fixing it, I figured out that the distributor cap was shorting the center post (coil wire) and #4 plug since the two run so close together. Yours sounds as though it has more of an intermittant short.

Oh thank you for the heads up, thats a good guess

[yekta]

ok so i went to schucks and bought this tool for 60$ But at least its a tool that I can use all the time... Never used this again so it took me a while to figure out where to snap it in, finally did figure out and here are the numbers

these are while the car is running

0*F 52psi
110*F 53psi
150*F 54-55psi
190*F 54-55psi

------------------------------

and these are the values first i started the car then turned it off and after that when i switched the car to the ON position

190*F 61psi
120*F 61psi
0*F 60psi

like i said this was my first time, so probly this is not even the right way to read these values So i will wait till u guys hit me up with some more knowledge

BTW car started itself 2 days later when I tried, like usual it cranked for about 6 seconds then started. I am assuming the material i added causing all these extra problems but somehow connected to each other, lately I put 1 bottle STP fuel injection cleaner and another bottle of oil cleaner, a bottle of lucas injection and system cleaner (which is 3 times bigger than the other bottles), a bottle of fuel booster, and a bottle of heet and then I filled up the tank. The next day car started doing this, acting like not getting gas, its choked or something u know. [PS car was fine except for the late cold start till I added lucas]

Now when I give a little gas car starts vibrating, this really started worrying me! and before I was able to start the car this morning, there was water on the engine, its like it sweated thats why i added some heet this morning I know I am a dumbass LOL. So I might just empty the gas tank

[MT-2500]

If the gauge is right your fuel pressure is to low.
You need 65 lbs. of fuel pressure to start the engine cold.
Leave the gauge on there and see what the running pressure is.
As outlined in the fuel pressure check I posted.
Check that fuel filter and if you can check the direct fuel pressure at the line going into the fuel filter.
A good fuel pump will have 75-85 lbs or more of direct fuel pressure there.

[yekta]

Originally Posted by MT-2500

If the gauge is right your fuel pressure is to low.
You need 65 lbs. of fuel pressure to start the engine cold.
Leave the gauge on there and see what the running pressure is.
As outlined in the fuel pressure check I posted.
Check that fuel filter and if you can check the direct fuel pressure at the line going into the fuel filter.
A good fuel pump will have 75-85 lbs or more of direct fuel pressure there.

yeah I left it on and its 54-55psi while its idling at 190*F. I will find the fuel filter now [if I can ] and check it out if the filter is bad by looking at the fuel pumps pressure. Fuel pump is attached to tank right?
when the car is OFF but the pump is ON it read 61psi

Btw what do you think about the additional material i added? Should I flush it all out?

[MT-2500]

Fuel pump is inside the tank.
I never had any faith with the cleaner stuff.
More or less a band aid.
You need more fuel pressure 62-64 running and 65 -66 lbs on start or engine off.

[yekta]

ok so here are the things I did
I changed the Fuel Filter
Found out the car was 92 not 96 LMFAO

saw this gap by the IAC valve (im not sure if its what it is, which is on the side of TB)

I have been following the sticky thread on How to section: http://www.automotiveforums.com/vbul...d.php?t=620747
I cleaned some stuff with break cleaner didn't help much

I can't get car to start, now i am replacing the rotor and the cap on the distrubitor and I think I am about to buy a whole new distrubitor! if not that probably will replace the plug wires also... Still not, i think I will find a hammer

I am convinced that I added way too many injection cleaner and other shit to the tank, thats why it was hesitating like that. I gotto get it running to flush the gas out and fill it up with normal gas tho So I am where I was started, sparking issue, electrical issue, whatever u name it.

I will also try to clean up the injectors with some gas and perhaps the regulator

PS that new rotor i bought is wrong bc cap wouldn't fit in, its bigger than the original one

[yekta]

What is that piece called and what does it do, anyone know?

[MT-2500]

Originally Posted by yekta

What is that piece called and what does it do, anyone know?

Thanks for letting us know how it went.
We are glad it is doing better.
That big black plastic/fiberglass is your Air condition evaporator core housing.
After you got everything back together did you set the base time on the ign. system?
If not the base time should be checked or set.
Good Luck
MT

[yekta]

Originally Posted by MT-2500

After you got everything back together did you set the base time on the ign. system?
If not the base time should be checked or set.
Good Luck
MT

Oh no, i didn't do that and probably thats why it is acting weird, is there a link telling how to set it so I can read the steps?

Im too careless God Damn it! I didn't pay attention to anything! i don't know the original distrubitors position and I donno how to set the timing because I threw all the manual to the trash

[MT-2500]

You might look around in the how to section on dist replace or intake replace how to or just set timing.
But the basic procedure is to find the dist bypass mode wire a single brown and black wire and unplug it and set bas timing and then hook it back up after engine off.
Some times behind glove box or under heater housing on near the fuel pump relay or dist.
What engine and engine code and what year for sure is it?

[yekta]

Originally Posted by MT-2500

You might look around in the how to section on dist replace or intake replace how to or just set timing.
But the basic procedure is to find the dist bypass mode wire a single brown and black wire and unplug it and set bas timing and then hook it back up after engine off.
Some times behind glove box or under heater housing on near the fuel pump relay or dist.
What engine and engine code and what year for sure is it?

its a 92 bravada 4.3, i think its called 4.3 CPI because that looks like my engine