My '94 with 180k miles has the off-idle hesitiation problem even with new opti, plugs, wires, egr, o2, etc., etc.

After reading the GM Memo about oiled air filters, I decided to clean my MAF again (I installed a K&N intake at 36k miles, and have on occation over-oiled the filter). I removed the MAF, used carb cleaner and q-tips to carefully clean the three hotwires, like I've done in the past.

Satisfied with the job I had done, but curious, I removed the screen to get a better look at the leading edges of the hotwires. I was amazed to find there was still a substantial layer of crud baked on to the hotwire leading edges! It took a bit more carb cleaner and some deliberate scrubbing with q-tips to get this crud off.

I also ran a cleantowel down into the K&N elbow, and was suprised to find a film of black, oily dirt inside, more than usual. I don't belive this would cause any wear to the engine, however I can understand how this crud would accumulate and bake onto the MAF hotwires.

I disconnected the battery for about a half hour to erase the long term corrections, and the car now runs much better, without the off-idle hesitation, or rough idle when hot. We'll see if the problem comes back over time.

I would suggest anyone with a oiled air filter to thouroughly clean thier MAF, with the screen removed. And be very frugal when oiling the filter.

 

Good info... thanks for reminding me to clean my MAF

 

I thought the wires inside weren't supposed to even be touched. What is the procedure for this, exactly?
Are you hitting the wires with a direct stream from the carb cleaner with the plastic extension tube, or are you just using the normal spray from the can and quickly hitting the MAF wires?
How hard are you rubbing it with the Q-Tip? (I imagine just barely touching it).
Do you have to worry about cotton fibers from the Q-Tip getting stuck on the wires?
Are you drenching the MAF in carb cleaner, or just lightly spraying it?

 

I use a stream of carb cleaner from the tube, directed at the wires, then douse the entire inside surfaces. Extemely light pressure with a q-tip soaked in cleaner, otherwise you can bend or break the wires. Fibers from the q-tips don't readily stick to the wires.

Take you time, and be patient, and the wires will come clean.

I wonder what GM's procedure is. They probably replace the MAF outright, and make a heafty profit, now that it isn't covered under warranty if a oiled filter is used.

 

Thanks for the tip.

I'll have to clean mine in the summer when it's insured.

 

FWIW, brake cleaner has seemed to work much better for me, as it dissolves the stuff better and also dries in the air right away.

No ill effects several thousand miles later, and it certainly helped right after cleaning (BLMs went up).

 

My MAF had some really really stuck on Crud. I carefully cleaned the little sensor things normally and used a flathead screwdriver tip to clean the bars going across it (VERY CAREFULLY). Cleaning it with Q-tips just didnt get the hard black caked on stuff. Gently scraping the black stuff with a screwdriver did the trick

 

After a few weeks and a few hundred miles, I'm glad to report that cleaning my MAF has cured my rough idle, off-idle hesitation at temp, and amazingly, my clutch shudder. The clutch shudder appears to have been a very bad miss at slight throttle, 1000-1200 rpm, light load (pulling away from a stop).

I've driven in bumper-bumper trafic, with the temp gage maxed and fans on, with no hesitation experienced. Plus, I'm getting about 330miles per tank, compared to about 270-300 before.

For all of you who have been battling the off-idle hesitation issue, I strongly reccomend you do a thorough MAF cleaning (temporarily remove the screen to get to the business side of the hot wires).

Considering the stock LT1 intake and filter was so restrictive, K&N and other oiled filters are installed on the majority of F-bodies. MAF oil contamination is a likely culprit for many of our cars symptoms.

Good Luck!!

 

I know this is off-topic, but what's your mpg, PGR?

 

330/15.5=21.29

Technically a touch more since I doubt he's running it empty, but close enough, eh?

 

I picked up ~20 g/sec airflow this week by cleaning my MAF. I was very surprised at the difference. It was definately noticeable SOTP. In fact, while scanning after cleaning to check the tune, I fragged my clutch. Coincidence? Maybe.

I used brake cleaner on a Q-tip, very gently rubbing the elements.

 

I usually average 22-23 mpg. Before I cleaned the MAF I was only getting about 18-20 mpg.

Once on a trip to LA I did 29 mpg, all 6th gear, 65-75mph.

With the MAF cleaned, it pulls so good at low rpm that I tend to short-shift more often, and spend more time in higher gears.

 

Electrical connection cleaner from your local Radio Shack works pretty well also, plus it leaves no film or residue.

 

My mechanic told this to me years ago(I posted many times),and I don't have the mas,but he suggested hitting the wires ever soo gently with cat approved carb cleaner,to make the engine run better.Seems the wires pick up alot of crud.(he works on all f-bodies)

 

After reading this thread I went and looked at mine it was black took q-tip and cleaner to it nice and clean now 5 q-tips later very dirty.