Cascade Crew

[Sellmanb]

Well, this isnt 3rd gen related, and I dont know how strict you guys are on this, but I know I'd get blasted out of TGO so I guess I'll give it a shot here.

My mom's 1986 Buick Skylark (4cyl w/ TBI) is running extremely rich, and idles horribly in park. When I put it to drive it just stalls (from too much fuel I'm guessing). So I suspect the fuel pressure regulator, and am looking at the book here and says to check the fuel pressure at different stages (priming, after prime, idle)... problem is, it has a metal tube line where it goes into the TBI thing... and my kit (that i just bought for 50 dollars? WTF?) only has rubber lines and the t-fitting with some clamps.

Is there a way to make this work without the rubber end squirting out everywhere when I go to check the fuel pressure? Do I need to go to a chevy dealership and ask them for a special fitting? Would they know what I'm talking about? Do I know what I'm talking about? LOL.

Thanks in advanced!

[Dewey316]

when I did mine, I had to actualy cut into the rubber line, there should be a short length of rubber line between those hard lines that connect to the TB, and the chassis lines.

The way TBI is regulated, its hard for the regulator to go bad, and create too much pressure. If you are making too much pressure, the return line would have to be clogged.

Is the engine throwing any codes at all?

A scan tool would be very helpfull, if the MAP sensor is not reading correctly, or something like that, then it will idle rich. Some sort of spark misfire is another likely problem.

[Sellmanb]

You know, my mom told me her SES light was on last night and I said I would check it in the morning and I totally forgot about it (d'oh!). I'll go out and check that now, thanks for reminding me!

[Sellmanb]

ok, I think you hit it on the head Dewey! I got a code 34, and a code 45.

34 - Malfunctioning MAP
45 - O2 sensing a rich condition

What this tells me is that the O2 works right, sensing the rich condition. And the MAP is malfuctioning causing the rich condition.

So I'll get a new MAP then. Thank you for the help Dewey!

[Sellmanb]

so I went and got a new MAP from NAPA, that didnt help much. I went and grabbed the O2 from my Camaro and put that in there, that didnt do anything, I checked the timing, and it sorta bumps 1 - 3 degrees difference as it idles (not AT 1 - 3 degrees, but a 1 - 3 degree difference). I got rid of the MAP error code by replacing that. I still have a 45, for O2 sensing rich condition.

I am running out of ideas. I checked the dizzy cap to see if it could move, or if the dizzy could move, and it was solid. What else could be telling the computer to just DUMP fuel into the car? Engine Coolant Temperature Sensor perhaps? Is there a way I can check that with a voltemeter? I have a new one on my Camaro that I can switch over assuming they're the same thread length and prongs I guess

I'm at a loss here folks

[Sellmanb]

So I put the CTS from my Camaro into it just now, and it can get out of park and drive now... but the idle is absolutely horrible, and it doesnt seem to have much of a powerband. I'm thinking it needs the oil changed, from all the fuel that was dumped in there. But I dont know what to do about the idle...

The drive idle (say going 20, but foot is off the gas) is fine and silky smooth. The stand still idle is verrry rough, like 2 plug wires are crossed, or some cylinders are missing.

I just did a tune-up to this car (plugs, wires, cap, rotor, oil, air filter, oil filter) about 3 weeks ago, I really dont think it could be that.

If anyone has suggestions I will gladly take them. Otherwise this car is going into the shop and my parents will disown me

[Dewey316]

are you still getting a the MAP error?

If you are check the tube comming from the back of the TB to the map, they are fairly fragile, and crack pretty easy.

Also, unless you unplug the ESC module when you check the timing, it will jump around. especialy if the computer doesn't know what you MAP value really is.

I suspect something is still funky with the values the computer is getting from the MAP sensor.

[Sellmanb]

I got rid of the MAP sensor error when I replaced that, so that was probably one part of the problem. I had the negative battery connector off while I changed it (so I could release the codes). I am unsure which connector is the ESC on there. There's a plug wire in the middle of the dizzy that goes to some other thing that i have no idea what it does lol.

After I put the coolant temp sensor on, i decided to give it a drive around the block, and while I was driving it, the SES light turned off (the one telling me the car was running rich). But still idled like terds.

I'm thinking I'll find the IAC and set that again or something? I'll check the vacuum hose and make sure it isnt brittle or cracked or anything. Another thought that I had though, was maybe a vacuum leak? But dont vacuum leaks typically cause a lean condition?

[chevymad]

It was probably your coolant sensor. Now thats fixed your plugs are all fuel fouled from all the gas it was dumping in. You'll have to pull your plugs again and either replace them or clean them. I like to take a propane torch and heat the plug tip till it comes clean.

[Sellmanb]

Genious! I put new plugs in, and viola! Idles smooth as glass now. One of the things I replaced also got rid of a smell that intruded the cabin, which was a nice plus.

Thank you Dewey and Chevymad!

[chevymad]

Just for future reference, when your motor runs really terrible it screws up the vacuum signal. This causes a map code. So just because you have a code for the map sensor doesnt mean theres anything wrong with it. Just means that the vacuum signal isnt matching what the computer expects it to be.

[Sellmanb]

Thanks for the info Chevymad, I had no idea how the MAP sensor worked, but it threw a code so i had it replaced heh. I will keep it in mind