Rough idle and car shakes on 90' 240

[240_2NRman]

when i start my car up it will idle up around 1200 RPM sometimes it will stay there and sometimes it will idle to 1000 and then 700-800, sometimes it will drop to about 400 and shake real bad. i replaced plugs and wires and all injectors. when its idling.... it seems like the car is misfiring a lil bit cause at the tailpipe it sputters... like a popping sound. ALSO.....most of the time when im driving...ill be cruising at a constant speed and the car will surge and i will see the TACH jumping around a lil bit.. it cant be me causing it with the pedal cause it does it in cruise control too.....please help..its getting really annoying. thanks.

Jeremy

Email: [email protected]

[dima]

Is it happens in wet weather?

[240_2NRman]

it happens all the time...it idles around 400 sometimes when its wet

[dima]

I think your distrebuter cap has small crack.Take it off and inspect for damages.

[240_2NRman]

would that cause the car to surge and all the other stuff?

[dima]

And better off start your car at night spray some water on it and rev your engine. Sometimes you can see blue arch. If you do than replace the part

[dima]

Probably not

[240_2NRman]

ok. thanks

[dima]

How about your massAir flow sensor?

[240_2NRman]

what would cause it so surge then?

[240_2NRman]

i was told to check that from a tech from JWT

[dima]

Good Idea. Bad Mass Air flow sensor can do that

[240_2NRman]

i check all those tomorrow and post what happens thanks

[dima]

But know they are expencive.

[NISTECH]

check your wiring harness to the air flow meter. also check for a good ground to the air flow meter use a volt meter and check the ground wire on the air flow meter place the positive probe of the meter on the gnd wire and place the neg. lead on the cyl head you should see less then .02volts if it is any higher then that you need to run an alternate ground off the air flow meter to the ground wires mounted on your intake manifold. splice it in parellel with the existing wire do not cut the existing wire.