Having a few issues getting my 82 to idle properly. I was hoping that someone here on the forum could help me out a little but seeing I feel like I am at a dead end

Got the car, didn't run or drive.

Replaced the battery, fuel pump, fuel pump sock and little connecting tube on sender unit, replaced fuel filter and one injector.

Now the car runs

but wont idle properly. Surges.

Replaced original spark plugs and wires.
Redid the top plate gasket, TBI gaskets and replaced the MAP sensor.
Seems to run better.

Will idle nice for around thirty seconds, high at first, and then as idle decreases it then goes back to its old habit of surging.

No check engine lights. Already plugged off vacuum at the main port on the rear of the manifold (to headlights and cruise) no change.

How bad would a broken egr soleniod connector make the idle? Do you think its s problem with the ECM?
Thanks in advance!

 

Check for vacuum leaks.

I can't remember how the choke is on those engines.

Did you set the timing properly?

You replaced one injector...how is the other one?

Air filters?

The ECM is most likely fine. Those things are fairly stable.

 

most of the time you will find a vacuum leak that causes this issue .... make certain the lid on the intake is tight .... they will loosen up and leak .... also gaskets under the TBs ..... would also check the EGR to make certain it's working properly and not leaking .....
There are also some treads on balancing the TBs and making certain the TPS is adjusted properly .....

 

If you haven't run the car for a good 100 miles it might be the ECM in learning mode. They seem to run erratic until the ECM figures out what's going on. So until then don't mess with the TBIs!!!
You said you redid the top plate (plenum) seal. Silicon doesn't cut it. You need the felpro gasket or it will leak

 

Can you take some pictures of both TBI's and the linkage? I need to see the angle of the plates in each TBI. There is one tiny slits inside each TBI at the 12 o'clock position (firewall side). Is the exact same amount of slit visible in both TBI's?

On cold start the ECM receives a signal from the CTS (collant Temp sensor) just below the thermostat housing. When warm it runs off the MAP,02 and TPS and some other sensors. After warm up the TPS plays a roll, it tells the ECM the position of the throttle plates, its how the ECM knows if you are idling or excellerating. If the TPS is set wrong ECM will think the idle is low and try to compensate. You need to make sure some of this basic stuff is not the cause, do you know how to adjust the TPS?

Surging could be caused by a number of things.

First cause is TBI tampering. See if the they were tampered with. the throttle plate angles will be different, use those slits I mentioned to see if they are different.

Second is if the throttle plates have been opened too much. I've played with this by opening them too much and the engine will surge. You should see part of the slit near the 12 o'clock position if the plates are close to factory settings. Thats provided they were tampered with, you need to see if the caps are popped of the adjustment ports and weld is broken of the idle screw onthe linkage, if this was done they have probably been tampered with.

Next is the IAC's. there is one on each TBI, they are on the front with harness wires going to them. With the air filter off, give it some throttle. Look down the holes in the TBI's at aboout the 5 o'clock position. Both IAC's have a pin, they cycle in and out and control air flow. Both should more exactly the same distance at exactly the same time.

If the timing is to advanced the idle will sure. You need a timing light to check this. Eyeball the distributor. Doe it look like its been moved, It should sit with the wires on the driverside prety well exactly at 3 o'clock.

Vacuum leaks are a major cause. You can eliminate all sources of vacuum leaks by disconnecting all hoses on the engine, i.e. disconnect EGR hose, hose to head lights, hose to PVC, hose to cruise control (if equipped) and hose to brake booster. See if surge stopes with each disconnect. Make sure to plug all ports hoses were disconnected from.

You say you changed the lid gasket. I hope you mean you changed it with the correct gasket, no silicon or home made gasket, they won't work.

Set the TPS to .525. You need a meter and two paper clips to stick inot the harnes to do this. You can take a reading for starters. Is it at .525 or within .007 of .525.

Jim

 

disconnect and plug the vacuum line to your EGR valve, if that fixes it replace the EGR valve, and yes the connector would cause a problem also

 

vac leak.start with the egr.then check the intake.something else i would check ,does your headlights work okay ?they work off of vacuum

 

I thought it was .525 +/- .075.

 

While not a crossfire had an 87 TB 350 that did the same thing.
New injectors/ECM fixed it wound up being the smoothest idling/reliable car Ive owned. Youll find it.

 

Too many zero's! Thanks. I have mine set exactly at .525...its a bit of a pain but can be done.

Jim

 

Me too. Just have to do it very slowly and compensate for how much it might change as you tighten the screws.

 

The injectors both spray the same, new and old so I think the other is good. As for the air filter, all the R&R I have been doing is with the air cleaner off

Already replaced the lid gaskets, and the gaskets for the TBIs. Do you have a link on how to balance the TBIs?

Did the gasket from felpro. I cant drive the car 100 miles seeing that the car surges and that means the throttle surges so driving the car is pretty much impossible. You can accelerate because the car bogs, hence this thread.

Pictures on the way. I have tried plugging all the vacuum lines with my finger, one by one, and the surging really doesn't change. When it gets warm it seems to surge less, but it is still there.

Did this, and no change
head lights dont work, BUT I plugged up that hose from the manifold and it made no difference in the surging.
Im thinking ECM, but I dont want to just throw parts at it, already did that...

 

can you get your hands on a vacuum gage ...... sounds like your not making vacuum at all ..>>????

 

EGR passage in intake a good suggestion forgot about that.

Mine was plugged solid had to clean it out for it to function right.

 

There is plenty of vacuum when I take off all the hoses from the manifold one by one...

 

Have you messed around with anything? Example TBI balance attempt? Timing? Or idle screw?

Jim

 

The only things I have done are the following:
Spark plugs and wires, fuel pump and injectors,TBI gaskets, and top plate gaskets. They all have improved how well the car runs and starts.

The three things you mention I have not attempted. I was thinking the next thing I would try is to see if the timing is off.

 

Can you look at the TBI's. Are the caps off the ports for the balancing screws? Is the idle screw still welded? The idle screw should have a bead of weld on it.

Jim

 

Here are the pics:
Jim, let me know what else you need pics of

 

The very right hand port is missing a cap! This should have been obvious.
Not trying to be overly critical, but, good gosh, did you not see this?


Until a cap is put on that, EVERYTHING else above is useless. Unbelievable - sorry but cannot believe such an obvious problem was not even recognized.