So I've been trying to figure out exactly whats wrong with my car. I can't get it to idle any lower than 650, I can totally remove the throttle body screw and it won't go under 650. It intermittently idles rough. When using an aldl cable, the maf reads like 6. something at 900 rpm or so, which I was told was low and that it should be like 10 gps at 450-550.

I noticed on the intake manifold, on the passenger side, under the runners, there is an oils spot that's always pooled up there. So, I wiped it up to see if it would come back, and it did. Could this be a runner leak or a manifold leak? Could this cause my issues? Thanks.

 

A common problem with these motors is that the engine oil will migrate up the manifold bolts and collect around them. You may want to remove the bolts from that area and put some thread sealer on them.

the idle speed is controlled by the ecm 650 rpm is normal

 

Hey thanks for the help, I appreciate it. It has some issues but they're not all that bad, just irritating. I'll check out the bolts.

 

If you think you have a vacuum leak, let the car idle, get a can of WD-40 and spray suspected area. If the rpm jumps up, you have a leak, if not wipe it off and check other areas the same way... John89 is correct about the bolt problem solution and idle.

 

Something more flammable than wd-40 works better.

Carb cleaners with a high naptha content....
propane
mapp

 

WHile this is true and I use mapp for this purpose, it does not sound to me like he has much experience, so I thought I would make it easy on him, starting fluid works well also!

 

Thanks guys for all the help. I'm pretty new with vacuum leaks, as they kinda scare me. Since I was 13-14 (now 18), I've pulled cylinder heads, replaced a lot of sensors, installed headers, rebuild a rochester 4mv (or whatever it was called), and many other things, but I'm really new with tpi stuff, so I'm still learning with this car. I restored a 1980 Cadillac Eldorado (ok well it was a really big refurbish), which was fun, having fuel injection and all the works without any diagnostic capabilities. I just don't want you to think that I'm a complete newbie to engines, even though I sound like it lol. Actually I kind of want to build an engine for this in my garage and swap it in when it's done, but that takes some $$$.

Oh yeah and thanks for correcting me on the idle John, that's one more thing that I don't have to figure out! Thanks for all the help too guys, I've heard about spraying cleaners and suck to see where the leak is, and I've done that on the Caddy, but I'm afraid of fire, as the Caddy once burst into flames in a college parking lot lol.