Stumbling mystery solved. MAF!

It is known that the EGR will cause stumbling when plugged but I just learned that the MAF does too. Reading MAF threads here mostly speak of poor performance caused by the MAF failure requiring replacement. Well I just discovered that the MAF also causes stumbling and unsteady power delivery but isn't a failed MAF. The plug in connection is very sensitive and needs to be cleaned, reset, and protected. I have since put silicone electronic insulating compound(not adhesive)in the connection and the difference is amazing. The power is super smooth throughout the entire power band. With how great it is now driving I also put the silicone in the MAP connection and am going to look into putting it in other critical connections. (like fuel pump harness) Just wanted people to know because I know there are others out there whos cars are basically running good but are stumbling slightly or are unsteady with peaks and valleys in the power band. I wonder if this could be contributing to the burnout of MAF's since a poor connection will cause voltage spikes in the delicate chip circuits of the MAF. By the way my connections looked good but...

>>silicone electronic insulating compound<<

Is that the same stuff as what is used on the inside of the spark plug connector, (not that I have any of those anymore). /images/graemlins/grin.gif

Yeah thats it. It aint cheap. Wierd thing is that my previous Dodge cars used it in the sensitive connections like to the computer and sensors. I just want people to try plugging and unplugging their MAFs a few times then take their cars for a ride to see if things improve. If they do then it is a good idea to silicone things up.

Possibly this is another connector to which one should apply Ox-gard or Deoxit, rather than silicone based stuff (which they strongly suggest should not be used anywhere near a MAF).

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... rather than silicone based stuff (which they strongly suggest should not be used anywhere near a MAF).

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And yet the entire inside of the MAF is filled with silicone /images/graemlins/crazy.gif

-Jason

That is the silicone sealant that you should watch around MAF and oxygen sensors. (like used for the oil pan seal) The fumes it gives off while curing are harmful. Electrical insulating silicone is safe and great for this application.

Could you give some brand names or types of this silicone? How about a national chain of some sort that might carry this product. (Ace, AutoZone, Home Depot, etc??)

YMMV

Mike /images/graemlins/cool.gif

I will look at NAPA. I have a 5lb tub of it that I use for work and I think it is made by 3M. I will find out this afternoon.

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<font color="green"> I will look at NAPA. I have a 5lb tub of it that I use for work and I think it is made by 3M. I will find out this afternoon. </font>

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Awesome, thank you, I appreciate your efforts.

YMMV

Mike /images/graemlins/cool.gif

Mike, I didn't make it to NAPA today but I am running out to work now to get the name off of it. My car is running absolutely flawlessly. I am amazed by the difference. It even starts more positively. I always thought the changes in power on its way up to 4,500 were just the nature of the TDI but now I see that it has a very steady power band. I have overrevved it a few times while testing it because it just zooms so smoothly up to redline. I don't know if it is getting to redline that much more quickly that I am not realizing it or what. Now mind you that other than the stumble recently it has run fine,,, but never this fine!

OK it is Dow Corning Electrical Insulating Compound. I will see if NAPA has it. It is also great for protecting door seals and rubber o-rings.

Thanks again for your great efforts. I will watch this post for information on availability. I could also try a local electronics shop here in Twosun, they have all kinds of stuff there.

YMMV

Mike /images/graemlins/cool.gif

I'm on my 4th MAF with only 48,000 Km and just over a year old. The last time I took the car back in for MAF replacement, the tech told me that he rewired the whole thing, replacing all the wires. He checked the wires and found the ground wire was burnt out due to corrosion and intermitency. When he replaced the MAF he also stated that he had put some anti-corosive stuff on the connections which he claims may have been part of the problem with these MAFs. The last MAF went in less than a month....You think they'll get it right?
/images/graemlins/frown.gif

I'm one of the lucky ones who hasn't had the MAF issue. Mine is 6years 88,000 mi old. I just can't believe the difference. Now that I fixed the connetion I realize that it never ran this good. Not even when brand new. It is crazy smooth. I wish I knew someone else with a TDI so they could drive it and see what I mean. Flawless starts hot and cold. Flawless running right off the bat in the AM. Great power. I can go on and on!!!!

Last night I sealed my connection with di-electric compound (can't remeber the exact name) and had very similar results. A much cleaner boost in power. Steady and more responsive than before.

I'm interested in trying this out.

This Dow Corning Electrical Insulating Compound or similar suitable brand - is it just applied directly to the surface of the MAF connection (both sides of the plugin)?

I have some of these slight peaks and valleys but otherwise engine runs well. I've got a new Pierburg MAF put in about 10K miles ago.

The Dow Corning is the only brand I know. It is just like the stuff in breast implants. (maybe not exactly but,,,)I filled the whole socket with it. That way is forces all air out and keeps moisture out.

If it smells like Acetic Acid (vinegar), DO NOT USE IT.

Skypup, the product sheet does not say it does not contain this but it does say it is oderless.

I put some anti-ox on my connection and I believe I notice a difference. I had been reseating the connector each time I had any problems with some success. I will keep an eye on it. Perhaps yet another fix?

Wow. This I gotta try. Any more input on other brand names and availability?

I'll post what I used tomorrow. But it was the same stuff I use on all of my electrical connections i.e. trailer lights, bulbs, connectors, etc.

OK I ran to NAPA and they have a similar product. I get mine from work in a 5 lb bucket for $500.00. The stuff at NAPA is Silicone Dielectric compount part# 765-1190. It is stable to 400 degrees F. Unlike the no-ox grease etc,,, it doesn't thin when hot. It is just clear silicone goo that never dries. Totally harmless and fumeless. You WILL notice a difference. I also put it on my MAP connection and this weekend I am going to put it where ever I can get it. Like in the fuel pump harness connection, speed sensor connection, needle lift sensor connection. Like I said earlier my previous Dodge vehicles used this stuff. I just assumed everybody did. They key is to fill up the socket then when you plug things together it removes all air. You might have to plug a few times or wiggle a few times. When I first put it in my MAF connection it was hindering the connection until I seated it by screwing around with it.

That's the same stuff I used. Also from NAPA.

Pep Boys also has it under the brand name Permatex Dielectric Tune-Up Grease, #22058, 3 oz tube was $4.85. SC

I just completed my 40K maintenance myself, oil filter, fuel filter, air filter, ECT. I’ve noticed since then that My 2002 NB auto revs right up to the red line with no problems. Prior to this it was having issues on the top end that I was blaming on my auto transmission. Then after the 40K maint. I thought it must have been blockage in the air or fuel filters but now I think it was the MAF connector. It hasn't been unplugged since the MAF was replaced under warranty at 32K. I unplugged it to do the air filter replacement. I’m gonna have to get me some of this silicone stuff cause I don’t want this to go away.
Deezel

I will bet you that once you put the silicone in you will notice even better running. For some reason having it in there makes the engine respond even better. Almost like the signal is altered just from air being in there. It will be interesting to know what the affect is on an automatic. Keep me posted!!!!

cage, did you saturate the all the pins and sockets or just the mating shell parts?

It is a vaseline like goo. You nearly fill the socket. What I did is goop it in then plug in the plug to force air out then goop more in. You can't totally fill it bacause there is a rubber seal that has to fit inside there too. Now when I first took it for a drive I noticed right off that it drove differently but 10 min into my drive I got onto the highway and floored the crap out of it and was doing 80mph+ by the time I got on the highway. It took off like crazy. Soon after I noticed it didn't have as much power. I got off the highway and reseated the connection a few times and it has been perfect ever since. You might have to plug and unplug a few times to get the connection right initially

Ok, it looks like my 2001 has the same problem with a flakey sensor connection.

Can someone clarify where this silcone-based electrical compound it supposed to go? Is it inside the socket of the connection I unplug whilst changing my airfiler?

Thanks,
Mike

Exactly. You fill it up and plug it in. You might have to kind of keep the release pressed and kind of slide it in and out so that it seats well. Remember DO NOT put silicone sealant in there. It must be silicone dielectric compound. You know you have the right stuff if it doesn't smell like anything.