GM Inside News Forum banner
1 - 4 of 4 Posts

·
Registered
Joined
·
7,803 Posts
Discussion Starter · #1 · (Edited)
Friend of mine has a 93 GMC 1500 4x4 5.7L California Emmsions with 4- speed Automatic that hesitates (cold or warm) from a 10 MPH rolling start under light throttle to about 30 MPH and will clear up and run smoothly at a constant 50 MPH.

It shows no code and idles perfectly.

It also hesitates if you "gun it" when running a 50 MPH but quickly recovers and the engine revs well.

Over the last 2 years the Fuel Pump and Distributor have been changed and the Fuel Filter was changed in the last year (2nd time).

It has just passed smog wth flying colors and timing is set at spec, plugs, wires and vacuum lines look good and the EGR checks OK.

Any ideas, we are thinking it maybe the fuel filter again (preferable to the fuel pump) 40 gallon tanks make poor dance partners.

The injectors seem clean with a good spray, the TBI is clean and the idle passages seem OK, the TPS was changed with no results.

Any help would be appreciated.
 

·
Registered
Joined
·
4,485 Posts
You said the distributor was changed...I'd still inspect...cap/rotor/magnets on dist shaft...

Check fuel pressures...but it's been my experience on the TBI's with fuel pump issues, either the pump works-or it doesn't...

Check the timing as well...
 

·
Registered
Joined
·
1,981 Posts
I have somewhat of the same problem, but I think i need a new distributor shaft. Check the distributor shaft. Anyway, has he replaced the fuel filter lately? Id do that, cheap and easy.
 

·
Registered
Joined
·
7,803 Posts
Discussion Starter · #4 ·
Well he finally took it in and got it fixed, it was the Coil!!!

It has been a while since he has been putting it off and only drives the Suburban about 2,000 miles @ year.

The shop had it for about a week and could not find anything on it on the Dyno or Diagnostic checks.

The guy at the shop finally just tried swapping coils with an old one laying aroung the shop and that was it.

Total cost just under $150.00 (parts/labor).

Hope this might help someone out there.
 
1 - 4 of 4 Posts
Top