89 Full Size Blazer 'Ghosts'

Hello everyone. I have joined this forum in hopes that someone can help me with my problem. I have a 1989 Full Size Blazer, Fuel Injected 350.
My problem: It starts perfectly. Will run for about a minute or so, then slowly stalls out and cuts off. It will restart with no problem, then run for about 20 seconds or so and cut off. It seems as if it warms up, and then this occurs. Once it is warm, before it stalls out, if you shift it into gear, reverse or drive, it dies instantly. As if it can't handle the load. WIll run in Park and neutral, but not in gear, at least until it warms up. It is driveable, if I 'powerbrake' it at stops signs and lights. But seems as if it doesn't have as much power either. Like it is starving. Upon starting to track this problem, several mechains have gave me their suggestions. Therefore the list of replaced parts has grown, but has not fixed the problem. If anyone has any ideas, please let me know. I am :banghead: beating my head against a wall here:banghead: .

Here is my list of replaced parts:
1. Fuel Filter
2. Spark Plugs - Bosch Platinum 2
3. Distributor Cap
4. Rotor
5. Ignition Module
5. Oxygen Sensor
6. Idle Air Control Valve
7. Map Sensor
8. Fuel Pressure Regulator
9. Throttle Positioning Sensor
10. PCV Valve
11. Gasket between Manifold and carburator
12. Gasket between carb and throttle body

These parts were bought, checked, and since no difference was noted, I returned them:
1. ECM Computer
2. Fuel Pump Relay
3. Timing 'adjuster' next to throttle body
4. Coil

I removed and thoroughly cleaned the fuel injectors, as well as replaced them with another set I had, and no change.

Checked for vacuum leak as well as replaced several hoses just in case.

And lastly, approximately one year ago, I replaced gas tank and sending unit.

Problem started one day out of the blue, and can't seem to figure it out.
Please HELP
I need to remove the demons!!! Thanks...Jason

Any check engine lights?

Did you check fuel pressure? Sounds like the pump or your alternator is failing.

Well, my next step is a Diagnostics check, which includes the pressure check. It will run me $ 80.00, but if it doesn't show anything, I am out that money as well. I bought the code checker computer form Advanced Auto, and the only code it showed me was the Oxygen sensor was bad. I replaced it, and now it shows no codes at all. That is as far as that went. Now real sure how the alternator would be involved. It has power to start right up, every time I try it, and would the alternator cause it to die out after it warms up? I guess it couldn't hurt to have it checked as well. It has a brand new battery as well. I don't know, I guess the diagnostics/pressure check is going to be next. Trying all I can before I do that. Thanks for the response. Any other guesses or suggestions? I am willing to try about anything!!!:banghead:

Well, my next step is a Diagnostics check, which includes the pressure check. It will run me $ 80.00, but if it doesn't show anything, I am out that money as well. I bought the code checker computer form Advanced Auto, and the only code it showed me was the Oxygen sensor was bad. I replaced it, and now it shows no codes at all. That is as far as that went. Now real sure how the alternator would be involved. It has power to start right up, every time I try it, and would the alternator cause it to die out after it warms up? I guess it couldn't hurt to have it checked as well. It has a brand new battery as well. I don't know, I guess the diagnostics/pressure check is going to be next. Trying all I can before I do that. Thanks for the response. Any other guesses or suggestions? I am willing to try about anything!!!:banghead:

First off, stop throwing parts at the truck.

From now on diagnostics comes first and then go to part replacement.

You putting the cart before the horse has cost you a lot of unneeded expenses.

Check the fuel pressure before you do anything, chances are the pump is weak. Then move on to diagnostics.

Well, Luckily some if not all of the parts that I have been nickel and diming have been bad, or by the looks of them, were on their way out. My truck spent the last five years in the 'rust' belt. Nothern Ohio. So salt and snow has taken its toll on it. So, some of the parts looked as if they weren't going to last much longer anyway. So that is why I don't feel bad about replacing parts like this. The most expensive one was no more than 40 bucks, so not a real big wallet breaker anyway. Is there a way to do a fuel pressure check myself? I have seen a hand held kit so to speak at Advanced Auto, but not sure if it was any good or worth it. It was like 50 bucks or so. I thought, for that, I might as well get the whole diag check as well. I do not know what the numbers are either that it should be pumping. Any idea where this info can be located? A Haynes book possibly? I really appreciate the responses...

Well, Luckily some if not all of the parts that I have been nickel and diming have been bad, or by the looks of them, were on their way out. My truck spent the last five years in the 'rust' belt. Nothern Ohio. So salt and snow has taken its toll on it. So, some of the parts looked as if they weren't going to last much longer anyway. So that is why I don't feel bad about replacing parts like this. The most expensive one was no more than 40 bucks, so not a real big wallet breaker anyway. Is there a way to do a fuel pressure check myself? I have seen a hand held kit so to speak at Advanced Auto, but not sure if it was any good or worth it. It was like 50 bucks or so. I thought, for that, I might as well get the whole diag check as well. I do not know what the numbers are either that it should be pumping. Any idea where this info can be located? A Haynes book possibly? I really appreciate the responses...

See if your friends have one or have them check it at the shop when they do the diagnosis.

That 89 has a TBI so have you checked that both injectors actually squirk and then check the pressure. Only one working would really bog. Also isn't the advance mechanical in the dist (been awhile since worked on these) so is it working (springs and weights that have to spin out or the timing will stay fixed and not advance. A timing light should tell you.

That 89 has a TBI so have you checked that both injectors actually squirk and then check the pressure. Only one working would really bog. Also isn't the advance mechanical in the dist (been awhile since worked on these) so is it working (springs and weights that have to spin out or the timing will stay fixed and not advance. A timing light should tell you.

The TBI has electronic igintion. Advance is controlled by the ECM. But thats not to say that there my be a problem there.

You say when you keep your foot on the gas as you brake, does it run fine when you do that? Has the idle screw ever been touched or adjusted? When the engine is cold extra gas is used to enrich the mixture to keep the truck running as it warms up. As soon as it warms up, the computer goes into closed loop and if the idle is off it will stall.

Did you check to make sure you don't a a vaccum leak, especially between the intake and TBI unit - very common.

Also check the coolant sensor when its warm, and see what the reading is. I don't remember what the reading is suppose to be search on here, its the same reading with the 4.3L engine, so you should be able to find it on here , but if the sensor is bad, but not totally gone, it will show a higher reading and really leaning out the fuel mixture and causing the stalling. It won't necessarly set off the check engine light, as its not toally gone.

Hows the timing on the motor, disconnect the timing bypass wire and try to start it. If it doesn't start you could have a timing problem, either way good idea to check the timing on it anyway, base timing.


Hope this helps.

It might be the timing out of adjustment and once he warms it up and the computer takes over the timing it will put it out of operational advance range.

Thanks for all the help. I was out of town this weekend, so I am getting to work on her tonight. I will check the idle screw. I have never messed with it, or know where it is for that matter, but I will play with it and see what happens. The gasket between the manifold and carb was torn, so I replaced it. BUt did not make it any better. No other vacuum leaks at all. All new hoses. I have a timing light, so I will check the timing on it as well. I hear it is a brown wire by the air conditioner in the engine compatment that I am supposed to unplug. Either there, or behind the glove box. I will try and locate it as well. :screwy: It just baffles me that it starts great, and actually sounds good while running, but the dies out after about two minutes. The injectors are still spraying up until the very last sputter of the motor. I have cleaned them and used high pressure to blow them out. Have tried another nearly new set, and same result. I will keep you posted. Thanks for the suggestions. I will keep trying....