Bonneville SE, 97 surges between 2000 and 2200 rpm under light load after warming up. Constant, rhythmic surge, not a sputter.

I disconnected the EGR sensor, no result.
Replaced the AIT (air intake temp) no result.

Any ideas?? Nice board by the way.

Rock on

Trev...any other info you can provide will be very helpful

Plugs and wires are what and changed when?
have you checked coils?
When was the last throttle body cleaning?
This is happening in 4th gear with TCC lockup right?

4th, at 2000 rpm only while lockup. Yeah. Plugs and wires changed. Only surges at 2000. kick it into a higher gear and it takes off. So, at WOT, as the computer ignores the sensors, it runs great.

It seems as though SOME sensor is misreading and the computer adjusts to compensate, then readjusts when another sensor shows resulting reading and then all over again. Makes sense because it'* a steady, rhythmic surge.

Oh, and I disconnected the AIT sensor and it ran fine...replaced with new and it still surges.

But what sensor is it? that'* the Q.

Rock on

Once TCC lockups any surging is typically in the ignition system.

What kind of plugs and wires did you put on the car and can you ohm test your coils by checking the resistance between the two leads on each coil pack. All 3 should be within a reasonable tolerance of each other.

[quote="BillBoost37"]Once TCC lockups any surging is typically in the ignition system.
[quote]

Hmmm.....someone else put on the plugs and wires. I'll check the coil and see what kind of readings I get. I was thinkin that if it was a coil problem, it would have little to do with temperature.

Rock on....and thanks for your quick replies, keep 'em coming.

Coils warm up as well internally and if there is a slight short or something it can increase with resistance.

One thing to keep in mind is many here have had big issues with using Bosch plugs and wires on bonnevilles. No idea as to why, they tend to burn up and cause this type of issue w/in a month or so of being installed.

Well, I reset the computer with the new IAT sensor in and it seems to have fixed the problem. Would resetting the computer do it????

Thanks

It could, if the IAT was the problem. it could also have reset the code or problem to only come back soon. Hopefully, all you needed was the reset.

Hmmmm.....yep, as predicted....the problem is back. Not quite as severe, but still surging. Gonna swap out the coil pack and see how that goes.....troubleshoting, what fun!!!

Thanks for all your help guys.

Trev