bucking/surging while cruising

[fast4door]

Recently picked up a 90 so as a daily and have an issue wit it bucking/surging when cruisng below 50mph. Its faint and not drastic but enought to be annoying. If i cruise on te highway above 60 its smooth. Car also seems sluggish under 2K rpm. Pugs r fresh as well as fule filter waiting to get some time this weekend to pull codes. Any ideas

Joe

 

[jimtash]

MAF, TPS, or plug wires.

 

[sperold]

The symptoms suggest oil in the plug wells, have you checked that they are new, yourself? If they are new, were they gapped?

 

[rubydist]

codes are the right place to start.

some of these cars will have a noticeable "hitch" when the a/c clutch kicks on/off - if the pcm is adjusting the iac too much it is an irritant. so it could be as simple as that.

or it could be any of the items mentioned above.

 

[sdpatt]

The codes may point to other possibilities such as the CID sensor, which can cause a bucking behavior. As said before, start with the codes.

 

[fast4door]

car is missing the self test input connetor (small gray plug) Have looked all around that area to make sure it wasnt tucked away and no luck. Anyone know wat color wire it would be on a 90 so so I can try to track it down? I want to get this issue resolved so the car is enjoyabe to drive.

Joe

 

[fast4door]

The symptoms suggest oil in the plug wells, have you checked that they are new, yourself? If they are new, were they gapped?

plugs were just done by me and the plug wells were clean. Cleaned the maf and still has an issue.

 

[kevinspann]

What gear are you in, and what speed when it happens?

 

[fast4door]

car does it in 4th and 5th gear and below 50 mph. Car seems to run fine at highway speeds. When driving in town cr doesnt seem to pull very clean through the gears.

 

[sdpatt]

If no telltale codes, it could be a secondary ignition fault such as leaking plug wires or short to ground at the plug. I had a similar condition that was caused by an arc path down the plug insulator. It left a black trail on the white insulator.

 

[trainguy1989]

Have to ask, did you get that very nice 90 from Peck, Ks?

Recently picked up a 90 so as a daily and have an issue wit it bucking/surging when cruisng below 50mph. Its faint and not drastic but enought to be annoying. If i cruise on te highway above 60 its smooth. Car also seems sluggish under 2K rpm. Pugs r fresh as well as fule filter waiting to get some time this weekend to pull codes. Any ideas

Joe

 

[jimtash]

plugs were just done by me and the plug wells were clean. Cleaned the maf and still has an issue.

Sometimes cleaning the MAF doesn't do anything. Unplug the connector and drive and see if you still have the same issues. If they go away, you just found the problem.

 

[fast4door]

Have to ask, did you get that very nice 90 from Peck, Ks?

ye sure did have known the owner for awhile.


Went ahead and ordered a new set of plug wires since the ones on the car look a little weathered.