'97 2.2 stalling

[302Z28]

I have been chasing a rough idle - hesitation issue for some time now. After replacing the plugs, plug wires, coil packs, pcv, pcv hose, TPS, MAP, EGR, IAT, coolant sensor, 02 sensor, crank sensor, cam sensor, idle air solenoid, injectors, fuel filter, fuel pressure reg, air filter, head gasket, and having cleaned all carbon deposits from the manifold, air plenum, throttle body and EGR passages, there is still a giant flat spot right off idle to about 1200 RPM. The car seems to run fine when cold. The engine has now started stalling when at a stop light in gear. Without any notice, the motor suddenly stalls like the key has been turned off. When restarting, it is immediate - no sputtering or cranking. Before this, the idle was rough enough to make the tach jump up and down. Now, the idle seems smoother, but you can hear more like a pulsating noise, UM, UM, UM, UM, UM when idling in gear. The tach says just over 600 RPM, but seems steady. I suspect a vacuum leak, but cannot find anything with a can of brake cleaner and a straw. Unplugging sensors does not seem to change anything. Could anyone please offer any advice? Thanks for any help.

[kirkwood158]

just took mine to dealer for very simular problem ...but I ve got the 2.4l

[Helmuth48]

Woo Mate...after all that work....I would have me a slab and somethin from the barbie just to recoup !!!

You made no indication about scanning for codes (CEL) ?? Remember...everything goes back to the ECU.....

I have never used Brake fluid to check for vaccum leaks...I always use propane...much more sensitive, BUT make sure to take the Durry out of your mouth and stay away from the barbie !!!

Cheers.... JzJzz and Donk...the Full Man from Down under .....

[kirkwood158]

it was FPR it made a major improvement....I my still have one bad injector though. I have got parts from auto store new out of box..... bad stuff like mass air flow two in a row and tps this cost me tons of money and time......like you. go back to testing stuff like compression (TESTER 20.00) tps can be culprit, low fuel pressure, OH yea they flashed my computer for cold stumble idle prob. more checks : plug gap, clogged cat. keep going