1994 GMC 1500 fuel injection problems

Old 03-09-2010, 04:34 PM
  #1  
laxking012
Member
JUNIOR BUILDER
Thread Starter
 
Join Date: Oct 2009
Location: Delmar, MD
Posts: 83
Default 1994 GMC 1500 fuel injection problems

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?
laxking012 is offline  
Old 03-09-2010, 06:31 PM
  #2  
johnracer
Senior Member
DYNO OPERATOR
 
Join Date: Aug 2005
Location: Rifle Colorado
Posts: 585
Default

What's it doing? Fuel pump and/or filter are common, but could be a number of things.....
Johnny
johnracer is offline  
Old 03-09-2010, 06:48 PM
  #3  
markdunlap
Senior Member
DYNO OPERATOR
 
Join Date: Jan 2004
Location: central Illinois
Posts: 459
Default 94 GMC

It never hurts to run a bottle of Lucas Oil Injector Cleaner thru it every 5000 miles. Might cure it?
markdunlap is offline  
Old 03-10-2010, 03:47 AM
  #4  
laxking012
Member
JUNIOR BUILDER
Thread Starter
 
Join Date: Oct 2009
Location: Delmar, MD
Posts: 83
Default

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.
laxking012 is offline  
Old 03-10-2010, 05:03 AM
  #5  
itsabird
Senior Member
RACING JUNKIE
 
Join Date: Dec 2007
Location: ohio
Posts: 816
Default

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.
itsabird is offline  
Old 03-10-2010, 05:10 AM
  #6  
ccperf721p
Senior Member
SENIOR BUILDER
 
Join Date: Nov 2008
Location: Phoenix AZ
Posts: 116
Default

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.
ccperf721p is offline  
Old 03-10-2010, 05:43 AM
  #7  
johnracer
Senior Member
DYNO OPERATOR
 
Join Date: Aug 2005
Location: Rifle Colorado
Posts: 585
Default

Originally Posted by ccperf721p
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
johnracer is offline  
Old 03-10-2010, 09:06 AM
  #8  
laxking012
Member
JUNIOR BUILDER
Thread Starter
 
Join Date: Oct 2009
Location: Delmar, MD
Posts: 83
Default

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.
laxking012 is offline  
Old 03-10-2010, 08:31 PM
  #9  
cepx111
Senior Member
RACING JUNKIE
 
Join Date: May 2006
Posts: 2,044
Default

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
cepx111 is offline  
Old 03-11-2010, 05:47 AM
  #10  
ccperf721p
Senior Member
SENIOR BUILDER
 
Join Date: Nov 2008
Location: Phoenix AZ
Posts: 116
Default

Originally Posted by johnracer
Originally Posted by ccperf721p
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.
ccperf721p is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -