The Jimmy has been cutting out/bucking/stalling for about a month now but it is getting progressively worse. In the beginning it would cut out for a split second once every 15 minutes or so but now it cuts out a couple times a minute, at idle or on the highway. Sometimes when it cuts out "hard" on the highway the brake and abs lights come on because I believe it is shutting down and restarting. When it cuts out "hard" at idle it just dies and needs a few seconds of turning over to get started again.

New distributor, plugs, wires installed 3 months ago to fix a p0300 and it worked perfectly for a couple months afterwards. Just did a fuel pressure check and it pumped to 60 and bled down to about 55 after 5 minutes. No SES codes. Any ideas? I'm thinking this may be fuel related- how do you test the injectors? This thing still has the original csfi injectors in it... 259k miles!!!

 

What did it bleed down to after 10 minutes (for the fuel)

 

It bleeds down to 50 psi after 10 minutes!

 

Should not bleed down .Needs a constant 60 PSI all the time.

 

Hello chknugget,

Not sure if your P0300 is pointing towards your original SCPI injectors.

I just changed my original SCPI injectors on my 97 to the updated MPFI.
ACDELCO Part # 2173028 or DELPHI Part # FJ10565
If you can afford it, this is a very nice upgrade. The change for me was dramatic.
Much better response and seems like more power. I am sure my old injectors
were on there way out but I never had any Cylinder misfires. They were very
brittle and the ends on some of them fell apart as we were pulling them out.

Mark

 

Ordered an injector, will let you know how it goes.

 

Replaced the injectors and it's no better... I'm going to have the coil checked and retest the fuel pressure but I'm otherwise out of ideas!!!

 

Still bleeds down to about 45psi after 10 minutes... Could this be the pump? What do I check now? Swapped coil and that did not help.

 

Would have to be pump unless you got a bad replacement spider unit. Did you buy a AC Delco unit. I wouldn't trust after market replacements. Does the new unit have individual injectors at the ends of the fuel lines? They are electric injectors not poppet valves.

 

I got a delphi injector unit... Checked the fuel pressure again and it seems to be holding at 55.

I'm thinking this might be the ignition switch. When it cuts out the ABS and Brake light illuminate.