[sm=helpout.gif]Hi, Need some help please! I have a 88 S10 4.3 TBI 217k miles ([sm=smiley20.gif]proud to say) that starts after a couple of cranks, runs fine, then at idle change the engine surges then dies. Same thing if I was to rev the engine. The CHECK ENGINE light is not on, at lowest point of surge timing is retard. No trouble codes. Spark Plugs, wires, distributor cap, air filter & fuel filter all have been changed. I don't think it is a sensor because I would have got a code (right?). I'll be checking fuel pressure after I post this. Maybe fuel regulator or pump? Suggestions will be much appreciated.
Thanks!

 

I would check the TPS and timings. It might be a good idea to check the IAC valve also.

 

this may sound like a stupid question but is there gas in the tank? the only reason i ask is becuase my 91 started doing the same thing and my gas gauge said i had a 1/4 tank. aparently my gas gauge is wrong by a 1/4 tank i supose.

 

Thanks for the reply,I'mstill: [sm=headbang.gif]. My timing is retard 15 degrees, and I thought about the IAC valve & others, but wouldn't they give me a trouble code with the diagnostic machine? Regarding the gas...go figure the rare time I do have a full tank, I may have to go playing in it. I tested the fuel pressure; with the key to acc position I hear the pump, the pressure goes up to 28 kpa then I hear a click & it drops to0. With it running it holds at about 35 kpa, but it still surges and dies.[sm=outcold.gif]Any more suggestions? This chick needs her ride back! Thanks!

 

Typically the only thing that wont trip a code is fuel related. Like fuel pressure.
TBI would be 9-13psi. CPI is 54-62psi. At least according to my Haynes book.

Do you still have a cat on the exhuast system? When was the last time it was changed? A plugged cat will cause an engine to die, especially at higher rpms.

 

Thanks for the reply, No cat just dual flowmasters. I'm going to change the fuel pump tomorrow. In another forum I read a thread that sounded very similiar and the mechanic said to change the fuel pump & remove the accumulatorthat's above the pump & replace it with a longer hose.Anyone else heard of this?