89 Z24 Stalls help ?

[BillGraham]

My 89 Z24 Cav (automatic) has intermittant stalling problem (happens appx. every 5-10 days.)Stalls when approaching stopping points.

When car is experiencing this problem, it also has lopeing up and down idle. Idle ok when not in stalling mode. Tachometer shows rpm fluctuates up and down between 5-8 rpm.
Car will actually move forward on its own without touching the gas pedal!
It lurches forward a few feet then idles down, about to stall then lurches forward again for a few feet, repeating this etc.

Other times the car idles fine with no RPM fluctuating and no stalling.
Even when car is stalling it runs great otherwise at least when giving it gas.

Dissconnected the trans torque solenoid switch, replaced idle air control valave, plugs, wires, pcv, fuel filter, ECM, had throttle body serviced. Cant find vacuum leak.

Does anyone have an idea ??
TIA,

Bill

[mentel]

dud i have the same exact problem.

it just started yesterday! exept most times it stalls when i start it up, and when i am about to stop it stalls . im thinking the throttle sensor? if you have fixed the problem let me know!

[71Shark]

Are you getting any error codes. If so, what are they?

When you replaced the IAC valve, are you sure the pintle was at the right distance from the base of the valve? If it is too far in, it can confuse the computer and won't reset itself. The opposite will happen if it's too far out - high idle. If you're sure the IAC is set correctly and you're cleared your codes, then I'd say TPS as well.

If all else fails, there's always those pesky O2 sensors that can be a real kick in the pants and cause all sorts of problems.

My $.02.

-Eric

[Pikachoo]

Well, my initial guess would be the TCC solenoid is not disengaging like it should, but it sounds like you've already disconnected that.. my only other thoughts are with the fuel system. Good luck!!:alien:

[91cav666]

yeah im in the same boat with my 91 cav when im pulling up to a stop light my rpm's change alot almost stalling then going back up i had this problem before and i then changed my ignition wires and plugs that fixed it for a while but it seems to be doing it again and i just dont have the funds to even take it to a garage soo n e help would be great..

[greendog]

I too had the same problem with my 94 Cav. RS 3.1
After much lurching, stalling and frustration, finally had the TCC solenoid replaced. Fixed the problem for about 3 years, but now it is starting to come back. This seems to be a very common problem.

Other users in this forum have reported simply unplugging it solves the problem. Just search the forum for stalling and you'll see lots of posts.

[richtazz]

did you disconnect the battery and reset the computer? The computer will not recognize the new parts until you do, and will continue to run like it did before. If you did, check your fuel pressure, as a bad fuel pressure regulator will cause symptoms like you describe. They will act up the most at idle because that's when vacuum is the highest.

[sambo eddo]

i had the exact same problem and a new tps sensor helped when it was adjusted right but it still acts funny.. what is this tcc thing that you talked about above and where is it located?...also .. what are some easy bolt on performance items for the late 80's z24's?....thanx for any help.