Okay I am a little stumped here on why my 86 has a funky idle. Here is a brief history so it might shed some light. I have owned it 6 weeks and the only thing I have really done to it so far is tune up stuff. A couple weeks ago i noticed fuel seeping from an injector, so I changed the Orings.

After putting everything back together the motor really has trouble staying idle on a cold start, i have to gently keep my foot on the gas. It runs great once I put it in D and hit the gas. It idled perfectly before I took off the upper intake so I know it is something I have done to it.

But here is the kicker... I will drive it around the block for 15min (just to get it warmed up, no hard driving) and come back to the driveway and put it in park and it will idle perfectly at 1200 rpm! I don't understand it. So I went around the block again as a test. Sure enough, came back and put it in park and it started having trouble again.

I don't know if it is throwing any codes as I don't know how to check it. I also need to order a Helms manual too. Here is what I think it might be

A) When I took everything off I cleaned the throttle body with spray carb cleaner. Maybe I clogged something? Maybe need to take off and reclean better?

B) When I changed the plugs I gapped them .30, which I don't think is right.

C) Maybe a minor vac leak some where? OR I got a Vac connector hooked up to the wrong place?

D) Cold start valve not working correctly?

E)TPS sensor not working? I don't know how to adjust, please advise

Maybe a clue for someone is that I hear a slight sputtering in the exhaust (very subtle) that started when I changed the plugs but the idle was fine then. i think that may be a gapping issue?

Is the first place I need to start checking ECM codes? I hope the engine isn't detonating b/c of my plugs and the idle is a side effect? But once again it didn't start till I took all the intake stuff off. Please help!

 

1200 RPM is too high for idle, you probably have a vacuum leak. If you removed the runners when you did the injectors, I would look first atthe cold start injector, it can be hard to get seated properly. Also it has an O ring on it that may have been cut or rolled.

 

I put oil on the CSV but the Oring is 20 years old...

 

get new o rings or soak the old ones in brake fluid for a few minutes. brake fluid has rubber conditioners in it, and whenever i pull an old o-ring, i treat it with b-fluid before reinstalling it. works great--makes old stiff rubber healthy and pliable. and it's dirt cheap.

i did buy a comprehensive o-ring kit from harbor freight for cheap, but haven't had a chance to use one yet. i admit i'm a little apprehensive about the quality of these rings, but i've seen the same kit on reputable sites for considerably more money. the chinese quality has improved greatly over the past few years-as it should have. they've stolen or bribed their way into all of our techno/trade secrets. chinese grad students work on goverment and private sector cutting edge research and take the results back home to momma.


political frog.