Low end engine flutter (1800RPM) J30

[alpar80]

1993 J30, just recently developed a flutter in the low idle range 800RPM and when cruise 1800RPM high gear. Thought is was a misfire, pulled all of the plugs and all are firing fine. Any ideas on what this may be? I was hoping that it could be a sensor or an easy fix? Where would one hook up an OBD? There are no check engine lights.

[gr8scott72]

1993 J30, just recently developed a flutter in the low idle range 800RPM and when cruise 1800RPM high gear. Thought is was a misfire, pulled all of the plugs and all are firing fine. Any ideas on what this may be? I was hoping that it could be a sensor or an easy fix? Where would one hook up an OBD? There are no check engine lights.

You can read one of the stickies at the top of the forum on how to read the codes on your 93. It's OBD 1 and you have to actually get to the ecu and look at the blinking light to get the code. Check there first and report back.

[alpar80]

I read the DTC from the OBD1 and came up with a "55", no code for 55. Five long blinks and five short blinks. Is this correct?

[yodawill2000]

I believe Code 55 is all systems are good.

Maybe a fuel filter issue ??

[alpar80]

Possibly, It seems identical to a misfire, I would hate to have to pay $110/hr for a tech to look at it!

[misfit6794]

A member over on the caddy forums had the same exact problem. His turned out to be a dirty iac. You can clean yours out with carb cleaner, just don't get any into the acutal sensor. Its also a pain to get to.

[alpar80]

IAC>?? Intake Air Chamber?

[yodawill2000]

Idle Control Circuit.

Do a search here and you should find the procedure .

[alpar80]

Where would this circuit be located?

[misfit6794]

It is actually a valve with a sensor attached to it. It is on the back of the intake manifold on the driver side. Its held in with 4 10mm bolts, 2 are easy to get to, the other 2 are a major pain, and then you have to get the hoses off, plan on just replacing them, I had to cut mine. Took about a hour. You could also have a dirty injector, clogged egr tube, or dirty maf.

[crossbones668]

Also check the hoses to the PCVs. A crack could be drawing a vacuum which would cause this problem.