So I replaced the spider injector, cleaned egr, fuel filter, plugs, was running great until this sudden idle prob.

Wondering if it's getting too much fuel again? These refurb injectors worry me, or could it be getting not enough fuel?

Fuel pressure test?

 

I'd run a fuel psi test. I don't remember the steps/specs but if you run a search on here theres acouple threads on how to do it the right way. & if that checks out I'd check for a vaccum leak. if you use brake cleaner & spray alittle at atime along the vaccum lines & the idle drops then theres your leak. if that checks out I'd crank it/ run it for acouple minutes then pull your plugs & see if there wet. if so then theres too much fuel if they're dry like normal. Then I'd be stumped..

 

1987 s10 blazer, 2.8, 4wd. I was having problems with fuel delivery and after testing found out my fuel pump wasn't putting out enough fuel. Tested at 5psi, supposed to be 9-13psi. After replacing, idle still rough with stalling. Next step was the fuel relay and then injectors. Idle still rough with no stalling now. Engine performed well when cold, but after warming up a little and also on any incline, the engine would bog down and lose power. Had to consult my old man with his 50 + years of experience in garages, and after taking a ride in it he pinpointed the problem, bad inginiton coil. Did the ohm meter checks and sure enough it was bad. I also want to thank all the folks who take the time to add information to this forum because I have been helped ALOT with other trouble shooting on my vehicle.

 

Never had experience dealing with ignition coil/ ignition anything, but I greatly appreciate anny feedback @ all. So the. Rough idle just went away suddenly as it appeared. Still begs the question as to why it happened to begin with. Does this fuel pump whine typically? Is it quite audible? Or would that be a sign of it working too hard? Gonna do a fuel psi test. Too curious not to! Thanks again guys.

 

if your roll the key the key forward but don't start it if your outside or some where kinda quiet you should be able to hear it whine for a second or two with your door open. thats just it priming.

 

it'll whine continuously. the whole time its running. that a sign of it being ****ty?

 

I don't know for sure. I can't say if I've ever heard mine running while the engine was running or not. My exhuast is to loud lol.

 

ya. the stock is quite loud in itself. have you modified your exhaust? air intake?

 

Yep. I have 4in k&N cone filter & a high flow cat. That dumps just behind the cat

 

4 inch k&n cone filter? and what dumps just behind the cat?