Hi. I have a 1993 SE Bonneville with 116k miles on it. Recently I have been having an issue where if I am at speed and lightly get on the accelerator I get some 'surging' type behavior - but as soon as I get on it hard where it may down shift I get normal acceleration.

This past weekend I started an attempt to correct the problem by throwing a set of plugs and wires on - it needed this anyway so was certainly not a wasted effort.

Am I dealing with a sensor issue? 02 or MAF ? Has anyone experienced this problem and if so, what did you find was the solution? Other than this, the car runs and idles great, gets expected gas mileage, etc... I am seeing no other issues.

Thanks and great website, found it last night.

Dan Beske

Try an 02 sensor and a fuel filter you probobly need these things anyways and I would get them taken care of.. I had the same problem and put some Marvles Mystery Oil in my Gas and it hasnt done it for about a month... If you dont want to spend the money on the the filter and effort... Buy a bottle of this stuff and see how it does... it definatly worked for me.

Dan, this has been an issue for me and a few others for a long time. You may want to check out this thread on Bonnevilleattitude.com as we have been working this issue for a while. It may help you, and if you find the cause, please let us know.

http://www.bonnevilleattitude.com/fo...opic.php?t=784

Cheers,

Thanks, Along. That is a nice thread. It exactly describes what has started to happen on my Bonnie. I am using Super America Gas - am going to try a higher Octane Amoco gas next tank to see if that makes a different. On the topic of the Coolant Sensor as suggested by Jupiter66 that fixed his 92sse, I need to figure out where that sensor is. This weekend while changing out the plugs and wires I found the lower bolt that holds 1 of the 2 coolant fans in place was gone, so I replaced that. While laying underneath the car putting a replacement bolt in I found a plug 'not plugged in' - I did not try to look very hard where this might go. It may not go anywhere but it seems strange for me to have a plug just hanging down there. Any ideas? I will need to track that down.

I am going to throw on 02 sensor in this weekend. At least I am not alone in my problems.

Great Forum and thanks for the replies.

Dan

Yes, I am going to search for that coolant sensor this weekend also. And I am putting in an O2 sensor this weekend, as well as a 180 thermostat.

Keep us updated

I just picked up on 02 sensor and Engine Coolant Sensor at Napa. The Coolant sensor was like under 30 bucks. According to Autozone it is:

UNDER HOOD, DRIVER SIDE, REAR ENGINE AREA, MOUNTED ON REAR OF INTAKE MANIFOLD

I will try these 2 out this weekend and post the results

It sounds like your problem, if just occuring in the warm weather, is caused by your MAT (IAT) sensor being unplugged. To check to see if it is unplugged look behind your airbox and directly below and to the right of your intake tube there will be a plug in, check to see if its plugged in. Also when/if you plug this back in make sure you reset your ecm, just pull the fuse.

A good fuel system cleaner is also recommended especially if you havent always owned the car. Chevron Techron is the best that can be bought on the shelf. Also if the MAT sensor is disconnected it will not make your SES light come on but it will cause the air/fuel mixture to be off.

I fairly sure this is your problem. Sorry if you waste money on your coolant sensor there.

Thanks Kuhl, I'll check that out. Man its gonna be a busy saturday

Blackstar, did you get an AC Delco O2 sensor ? I have heard horror stories about the Bosch ones screwing up things. The Bosch ones are cheap, the AC Delco ones cost about $34 for the 92 SSE. (cos I just bought one)

If you bought a Bosch one (or another brand that is a Bosch relabeled), I would suggest you return it and get an AC Delco instead. That seems to be in common agreement here.

Cheers,

Thanks for the info, Kuhl. Unfortunately that is not where this 'lost plug' belongs. I looked tonight and just cannot see for the life of me where that plug belongs. It is not a very long plug and anywhere that I try to move it there does not seem to be a place to plug it in.

I did buy a Bosch 02 sensor but am going to return that and pick up an AC delco. I am not quite sure yet if I want to dive in to the Coolant sensor either. Going to give that one some thought for a while.

Meanwhile, the problem still persists. I will try a different tank of gas and some chevron additive next.

Thanks everyone.

Hey Guys,

I changed out the O2 sensor, that was real easy ! Just used an adjustable wrench

Also put in a 180 SuperStant T-stat. That was messy but now its done and running under 200 degrees !!

O2 sensor didnt help with the surging/stuttering in overdrive, but the idling is smooth now and hope I'll now get better than 22Mpg on the highway

I found a vacumn hose that had come off and put it back. Maybe that fixed the idle problem.

Anyway, that was my 92 SSE. Next week is my 97 SSEi 180 T-stat.

Cheers,