GM Troubleshooting Part 5 - Fuel System including filter, pump, injector, regulator

[jimbo4261]

My 1995 Jimmy 4.3 will start on a prime but will not keep running,,the mechanic tested the engine and said the cam/crank sensor was bad,,how can that be if it starts with prime but wont keep running,,sounds like lack of fuel to me,,,any help,,greatly appreciated,,,ole fart Jim

[mrsillyman]

@jimbo4261 I would agree... start with checking your fuel pressure at the rail... maybe a dead fuel pump or fuse or relay. Let us know what you find out.

[kenjackson1977]

1991 Chevy k1500 4x4 5.7 liter...i changed pump and sending unit.....fuel filter....fuel relay,checked fuse,new distributor,new starter,plugs wires,map sensor o2 sensor, still turn key and no pump is coming on....i have spark....i jumped hot wire from battery to pump and pump kicks on....would that be ecm or wiring harness?

[kenjackson1977]

@kenjackson1977 still after doing so it wont start unless i add fuel in the throttle body.

[mrsillyman]

@kenjackson1977 sounds like ECM to me since you jump it manually and the pump kicks in. before replacing the ecm, check all grounds that go to the ecm wire harness to ensure 0 ohms (or near 0) to the negative terminal of the battery. let us know how you make out.

[MrMusicDreamz]

With what @you2bertoo said, I have the same trouble. Was rear ended, not too bad but after that my f filter went bad. I changed it and verified later, still good but on cold starts and often in between, I must use starter fluid and it runs great! I have a astro. I think I might be a weak fuel pump from my accident. I don't think it's the fpr because it don't smell gassy. But it's possible I need new plugs. Can't get enough room in there with those dumb heat shields! Anyway, thanks man for this!

[you2bertoo]

Great video but I have the opposite situation. I changed the fuel pump yesterday in our 97 jimmy and it is still starving for gas. I can get it to start with starting fluid after several tries. There is no smell of gas, no black smoke. The fuel filter is new. I can hear the fuel pump run. Any ideas?

[mrsillyman]

@you2bertoo Hey there. put a fuel gauge on the fuel rail and determine if pressure is up to the specification. If too low, and you have a new pump and filter and tank is sufficiently full of fuel check for either a plugged line or weak regulator... and report back... if pressure is correct, you may have clogged injectors OR maybe your computer is not telling the injectors to open at all. It is always good to check grounds and fuses... report back and let us know

[spelunkerd]

It's almost criminal what some Canadian stores charge compared to a competitive US market. Effectively they take advantage of those who are afraid to shop outside the country. But at the end of the day they lose.

Regarding the spider, I missed the part where you found a diagnostic 'fail' of that part. I guess the asymmetrical washed plenum was a big clue. With the cost of that part, I would be crossing my fingers that the problem would be solved by replacing the spider.

[mrsillyman]

Hi there... yes... I saw the washed aread of the plenum and expected a faulty pressure regulator or broken spider line on that side. However, a crank did not show any leaks...but the plenum cleaned up somehow... i thought maybe it only leaked when hot or something. That, coupled with my suspicion that my injector was sticking open led me to replace it. In the end, I don't think it was faulty but $200 was a reasonable price to pay to get a rebuilt injector, new regulator/poppets and spider.

[thesmdstudio]

Great video awesome with the info. I think I can do it now, after watching this vid. Thanks:)!!!

[themazur]

good video, im having the same problem with my 2003 gmc sonoma 4.3 vortec, and was just wondering where you got your spider injector from, and if there is a website. Also, did they deliver to canada?

[fasttac92]

@themazur You dont have spider injectors. This was discontinued in 96. you have MFI and not CPI

[dosteddaram]

nice description keep so