Will not Idle, Boost Gauge reads vac side, HELP!

meiersc

Registered User
I recently put my Tbird 1990 SC back together, after almost 2 years of being apart. I was deployed.....and alot of other things were taking up my time. I had to take it apart because the damper pulley bolt broke off...which was a pain. After removing what was left, and replacing it all, I put the car back together. It wouldn't run due to bad timing, which after getting the right tool I was able to fix. Now....it will start, and I can pump the gas pedal to make it keep running. But it will not idle. I thought it was vacuum lines, but I don't think I am able to read the diagram I have correctly, as there are some abbreviations on it that I do not know what the mean, such as FPR?????
While pumping gas, the boost gauge shows needle in vac side. What to do what to do! Anyone got any suggestions? I think i just need a diagram I can read....but I am still not quite sure that vac lines are the problem.
Please help-
Confused, Matt
 
well...

It wont idle ..
But while giving gas, its supposed to read boost,
and instead its reading vacuum.
Any ideas?
 
Is the blower bypass valve actuating? It is the valve directly behind the blower. When you excellerate it should go to full open.
Clark
 
hmmm....

When I think I have a vaccum leak, I take off my filter, and put my hand over the front of the MAF sensor (covering ALMOST all of it) while the car is running (someone will have to start it up for you). This will limit the air going into the motor, and should allow it to run correctly, as if there was no vaccum leak. I pin pointed mine as the EGR tube was connected :eek: . Anyways you might want to try that first.
 
News!

OK I have sealed the IC tubes and guess what....
It runs! Its running at a high RPM so I am going to recheck the vacuum lines and plug wires. Thanks all for the great advice!
 
The hose off the Passenger side PCValve splits. One end (5/16" ID) goes to the inlet plenum, and the other end of the 'Y' is a 1/4" ID rubber tube
Anyway, the rubber 1/4" ID tube tore open, and it would sometimes idle, but when it got to operating temp would not idle. I would put the AOD in neutral and use my foot to keep it running. Replaced the tube & now it idles again :cool:
 
Check IAC

You might want to check the IAC (Idle Air Control Valve) on the throttle body. A vacuum won't let it idle high, it should idle lower and kinda rough with a vacuum leak. The High idle is quite often the IAC, especially if it has been sitting for a while it might be stuck open a little bit allowing more air to get into the intake than normal. Remove the plug from the IAC and see if the idle gets better. if not than the IAC is stuck open a little.

Some folks have had some small success cleaning the IAC, but that is only a temporary fix, but it may get you by for a while.

Hope this helps,
Smitty
 
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