Just to get it out in the open. I am a newbie. I have basic knowledge of how to work on cars. If I know what is broken I can take it apart and fix it. I’m just not that good at diagnosing problems.



I just purchased a 1988 Pontiac Firebird (Formula V8-5.7L, Vin 8, 350ci).

The guy I got it from just rebuilt the engine about a month ago.

It starts up fine and idles fine. When i drive it it kinda bogs down when i excelerate and whe I sit at a stop sign or red light it idles real rough and stalls on me if I sit to long.

It has a couple of vacuum leaks and an exhaust leak.

Took it to O Reilly’s and had them run the test on it and it came back with the following codes.

· 32 – EGR Failure
· 33 – MAP (Volts HI/Vac LO)
· 34 – MAP (Volts LO/Vac HI)
· 36 – MAF burn-off

I replaced the EGR valve yesterday. And now I am thinking I should have left it. The new EGR valve that I got (from AutoZone cause they were $50 buck cheaper) looks the same as the old one, except for where the heat sensor screws in. The original heat sensor is about 1/4 inch and the new one has a hole that is about 1/8 inch. And I noticed in one of the threads that this sensor is very hard to find. (I did see 8588’s post about a way to fix that).

I have a couple of pictures of some vacuum lines that are just kind of sitting and going nowhere.

I am not sure where the MAP sensor is, can someone point it out for me?

 

Well, IIRC, an 88 should be a MAF car, not SP. The MAF burnoff should be fixed by replacing a relay on the driver side firewall next to the brake booster. The little thing that has a strong suction on it needs to be plugged until you get more info on it, because as of right now it's a big vacuum leak.

I don't know why you're getting MAP codes unless that leak is causing the computer to go crazy, hopefully someone with a little more technical know how will chime in.

 

Thanks for the help.
I just stuck a bolt in it to plug it.

 

Code 32 and 36 are correct and codes 33 and 34 are for the MAF sensor . Check the power on all the wires except the black/white wire as it is ground . The burn off relay gets 12v constant power from the orange wire that has an inline fuse and the other 12v in comes from the ECM fuse black/pink wire . The MAF has 4 or 5 wires on it .

 

Thanks, checking those now.

 

You're welcome . Let me know what you find and we'll go from there .

 

Took me a little bit to get to it. Had company come over.

Ok, now I am probably ging to sound stupid here but which one is it?

There are 4 things located to the right of the brake booster.



In the RED circle the wires are

• Pink/Blk - HOT constant
• Blk - nothing
• Brown - nothing
• White - nothing

Orange circle

• Thin Orange - Hot constant
• Thick Orange - nothing
• Green/White - nothing
• Blk/White - nothing
• Tan/white - nothing

Yellow circle

• Orange - Hot constant
• Blk/white - nothing
• Red - nothng
• Blue - nothing
• Tan/white - nothing

Green circle

• Orange - Hot constant
• Orange - Hot constant
• Blue - nothing
• Black - Hot when plug in

I have more pictures if needed.

 

Came across this when i was looking at the other stuff.

i thought it was a hose for the washer fluid at first.

I tracked it back to the thing that is hooked to the gas cable.

See pics

 

Vacuum line for your cruise control. Line marked with red is source vacuum. Line in yellow goes to the brake switch, inside the car, and releases vacuum when you step on your brakes. (closing the throttle)

 

thanks.

Where should the red line (vacuum source) be plugged into?

 

should be a T fitting on the passenger side, toward the very back of the motor. There are a couple vacuum ports on the Intake plenum there, and one of them should run to said T fitting.

 

I think the relay in the yellow circle is the burn off relay . Ohm the black/white wire to ground and the red and blue to the MAF . If that is it then the tan/white would be power with the key on .

 

Thanks, going to try messing with it again today.

Had to work the last couple of days.

 

Ok, I finally got back to working on my car.

I really got into it this time and managed to fix it.

The previous owner rebuilt the engine but he forgot to tighten the bolts on the passenger side exhaust manifold. So I took it apart and replaced the gaskets and I also replaced the MAF. It runs very nice now. Idles at 600 rpm.
And when I press on the gas it actually moves. WooHoo.

Now I am going to start working on the AC and Heat.

Thank for the help everyone.

I will be posting more questions later.

 

In your first post, the middle pic, the long thin vacuum line that's "just sitting here; not hooked-up to anything" looks like the line that connects to the top of the heater diverter valve. But you don't show the valve in the pic, so I can't see if it's hooked-up. That's the large black plastic valve with a coolant hose coming from the throttle body and the heater hoses running to the firewall and the radiator. Looks like this:

 

There is something that kinda looks like that. I will take some pictures in the morning and post them.

 

No need to take pics of it because nothing else under the hood looks remotely like it. So if you have something that looks like it, then that's it. Does it have a hose connected to that nipple on the top? If not, then that's where that vacuum line connects.