Car starts then stalls 10 seconds later

gmc
sierra1500

#1

So i drove home from work and everything was working fine then i stopped at a store about a block away from my house. When i started my car again and started driving it felt like the one time i ran out of gas (6 years ago). I made it home but since then my car fires up every time without a problem but then it immediately starts dropping rpm. It will try to regain rpm but then eventually stalls out. It usually takes about 10 seconds. I checked the fuel pressure which was fine. There are no trouble codes either. Where else should i be looking?

1999 GMC Sierra 1500


#2

The problem is, if you don’t provide the year of the vehicle, nobody can look up if there’s even TSB that might be related to your problem

Tester


#3

When you checked the fuel pressure, were you measuring it as this problem was actually occurring? It does sort of sound like a fuel problem of some kind. If it’s not a fuel problem, and w/no diagnostic codes, may prove difficult to figure out. Your best bet is probably to have a shop do a diagnostic, then you can fix it yourself if you like. My guesses, if not a fuel pressure problem, next would be to check for spark. If fuel and spark test out ok …

  • the idle rpm control mechanism is failing, throttle valve is sticking, etc.
  • heat-related obstruction in the exhaust system

#4

suggest to change the fuel filter, cheap, easy and quick to do on this truck.


#5

I agree with @kurtwm2010 Fuel filter first. If its partially clogged it might pass a pressure test at idle and fail when real flow is required. Same issue for the fuel pump. Pumps are cheap but a bit harder to get to.


#6

Thank you for the advice. I will start with the filter and re-run tests.


#7

So i changed the filter and it fired up and ran just fine. Then i reved it up and held at a few different rmp’s and it held just fine. Then the next day i went to drive it. It started up fine but then about a quarter mile down it started failing on me again. When i first turned it on i had primed the engine a few times so it had fuel. Is it possible that the pump can provide some fuel but not keep up once it is actually going? When it died i was able to get it going for a couple seconds at a time and get it over to the side of the road.


#8

Sort of sounds like the fuel pump may be faulty. Replacing the filter probably made the fuel delivery job easier, so it didn’t fail as quickly as before. But eventually it gets tired and fails. Yes, it is quite possible for a pump to be able to deliver fuel flow for a while, then quit. Or to deliver enough to run the car at lower rpms, but fail at higher rpms. However, If I had this problem I wouldn’t replace the fuel pump until a fuel pressure test confirmed it was bad. Sometimes you have to run the engine on the road while monitoring the fuel pressure to figure out what’s happening. And good fuel pumps can fail intermittently like that if their power get interrupted for some reason, bad relay, or fried electrical connector. I had that problem years ago on a VW Rabbit, fried electrical connection to the fuel pump.