1994 GMC 1500 fuel injection problems [Archive]

laxking012

03-09-2010, 04:34 PM

I didn't know where to post this so i figured this was as good as place as any.... My 1994 gmc c1500 is not getting enough fuel and i'm wondering what the reason is? Where is the best place to start looking for problems? or maybe it's just dirty injectors and some injector cleaner could solve it?

johnracer

03-09-2010, 06:31 PM

What's it doing? Fuel pump and/or filter are common, but could be a number of things.....
Johnny

markdunlap

03-09-2010, 06:48 PM

It never hurts to run a bottle of Lucas Oil Injector Cleaner thru it every 5000 miles. Might cure it?

laxking012

03-10-2010, 03:47 AM

When i get on the throttle there is a delay and when i'm at higher speeds like 50 or so when i try to speed up some it kind of stutters. Also when i hold a constant high speed it will.

itsabird

03-10-2010, 05:03 AM

i would start with fuel filter, and dump a can of injector cleaner in it. most pump prob i have seen, are they just quit.

ccperf721p

03-10-2010, 05:10 AM

Most common problem would be the fuel pump or filter, easy enough to test fuel pressure. That system will need 60-70 PSI to operate properly.

johnracer

03-10-2010, 05:43 AM

Most common problem would be the fuel pump or filter, easy enough to test fuel pressure. That system will need 60-70 PSI to operate properly.
Actually, a 94 should be TBI and only has around 14psi. I'd definately start with a fuel pressure test. On a TBI, it's usually easier to tee in at the filter. It should have 14psi or so all the time. If it's low, try capping the return line to see if it comes up. If it does, it's the regulator, if not, it's the pump or filter.
Could also be a cap, rotor, or wire issue. Those tiny caps are prone to crossfire if the wires are marginal.....
Johnny

laxking012

03-10-2010, 09:06 AM

I just replaced the fuel filter and it didn't make a difference. I guess next i'll buy some injector cleaner and try that.

cepx111

03-10-2010, 08:31 PM

Had a similar issue with my 95 suburban, after replacing fuel filter, pouring in a couple can injector cleaners, and replacing the fuel pump, (twice) found out it was the fuel pressure regulator. :shock:

They make a rebuild kit for it too, $40 bucks autozone.

Goodluck, Cp

ccperf721p

03-11-2010, 05:47 AM

Most common problem would be the fuel pump or filter, easy enough to test fuel pressure. That system will need 60-70 PSI to operate properly.
Actually, a 94 should be TBI and only has around 14psi. I'd definately start with a fuel pressure test. On a TBI, it's usually easier to tee in at the filter. It should have 14psi or so all the time. If it's low, try capping the return line to see if it comes up. If it does, it's the regulator, if not, it's the pump or filter.
Could also be a cap, rotor, or wire issue. Those tiny caps are prone to crossfire if the wires are marginal.....
Johnny

You're right, thanks for correcting that.