Car shuts off after a couple minutes

I have this weird problem with my 1999 Chevy Blazer 6 Cyl 4 WD. When I start the engine, the car will run for about 1 minute or a few minutes at most, and it will just randomly shut off. I can put the key back in and start it again but same thing will happen and I think second time it shuts off even faster. The car looks like it is shaking/jerking, struggling to stay on before it finally shuts off. The RPM needle moves up and down while the car is almost shutting off. If I open the hood, I can smell some burning smell, not sure what it is. maybe something overheating causing car to shut off? Sometimes after it shuts off, I put the key in again and it will just keep cranking but won’t start. I have to wait a while and come back later. I feel like maybe something is overheating so you have to wait for it to cool down. Or something is clogged and you have to wait for it to unclog itself.

I’ve replaced things like air filter, spark plugs and wires, cap and rotor, coil and ignition module, fuel filter and crankshaft position sensor, cleaned throttle body, etc over the last year. None of them should fail this fast, right? so it should be something else? This is a twenty four year old car with about 112,000 miles so there is probably something old that needs to be replaced. Maybe coolant temperature sensor, PCV valve? My buddy suggested maybe spider fuel injector clogged so fuel not getting to the pistons. But I have to remove so many things to check the fuel injector to see if maybe it is the problem or not.

I checked the fuel pressure and it looks like it is at 54 psi. engine off key on, and idle psi are both 54. Is 54 ok or just a little bit too low to keep the car running? I think it has to be at least 56- 60 psi. I just changed the fuel filter and I can hear the fuel pump priming. The fuel pump relay is good. So the only thing left is the spider fuel injectors?

I also have a problem with my car door lock. When I press the lock/unlock button on the door switch, I can lock and unlock all doors except the front driver door. I can manually pull up and down the lock on the door but it is not responding to the door switch. What’s the problem here? door switch, rod, latch, actuator, or wire? I can hear 2 locking sounds from the driver door, sounds like it is locking and unlocking by itself, or it is trying 2 times to lock/unlock the door. The front driver side door lock is not responding to the door lock button on the door switch.

The fuel pressure is too low.

It needs to be 56-63 PSI in order to blow open the poppet valve injectors on the spider assembly.


So the fuel pressure being at least 2 psi too low makes a huge difference? It is 54, pretty close to 56. Can’t the car just get by with the fuel pressure just a little outside of the range, you know what I mean?

How can the car even start if the fuel pressure is too low? When I start the engine, the car runs fine for about 1 minute. You don’t notice anything wrong with it, no sound, no shaking. After 2 minutes, it starts to jerk/sputter/shake and looks like struggling to stay on before it eventually shuts off.

Do I have to replace the spider injectors or can I clean them because maybe they are just clogged? So fuel isn’t getting through causing the low fuel pressure?

I’ll type it again.



54 does not equal 56-63.


Ok, lets look at this another way maybe… When it starts trying to stall out can you keep it running using brake cleaner or starting fluid of some kind??? If so you are back to the fuel problem as already stated…
If that doesn’t help then use an inline spark tester to see if you are loosing spark…
If you have spark and plenty of fuel pressure as already noted, then check for compression…
If compression is within spec (unlike your fuel pressure) then is your exhaust stopped up…

You have a air pump that requires air to be able to enter and exit the engine, add a little fuel and spark and it should run… computer controls aside…
You just have to figure out which one is failing, and from the sound of it, sounds like you have already been advised what is not working correctly…

BTW: it’s not like GM is know for having the best fuel pumps on the market…
Also don’t go cheap on the pump, Airtex are not reliable, I have warrantied way to many to use them…

I would only use a Delphi fuel pump module assembly for a GM…

Trying to identify a stalling issue, I would drive around with the fuel pressure gauge taped to the windshield. You don’t know what the pressure is when it stalls. At any rate probably all those parts were needed anyway. Next $100 should be to a mechanic for a diagnosis. Should be easy to find.

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Or at least ask a pro-mechanic to measure the fuel pressure. It’s a pretty difficult job for a diy’er to get an accurate enough measurement using commonly available diy’er test equipment. Or are you reading the fuel pressure using your OBD II scan tool? If you simply want to replace something rather than measure something, suggest to replace the spider assembly.

He did measure something, and it’s below spec.


I used Autozone fuel pressure test gauge

likely not possible. I don’t believe this vintage had a sensor for fuel pressure, so the computer doesn’t monitor it. It either starts, or it doesn’t.

It already has a tolerance range and yours is below the minimum specification. If it could run reliably at 54, then the specification range would go down to 54. But it doesn’t- for a reason.

Pretty close works in horseshoes though… :slight_smile:


… and with hand grenades…


No experience w/Chevy, but my old VW Rabbit with mechanical CIS fuel injection was pretty particular about the fuel pressure. It had to be pretty close to spot-on to run well. It sounds from the descriptions above your fuel injection system has a mechanical component, fairly high minimum pressure required to presumably overcome a spring & force open a valve. It makes sense to be doubly sure that minimum pressure is being met. Suggest to get a second independent measurement on the fuel pressure.

When I had a fuel pump problem or at least one of the many times, I went to the schrader valve and pushed it. Gas squirted out but just not enough to run the car.