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Snowman

MAF sensor cleaning...who'd a thunk!

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Here's a collection of anecdotes from my soob adventures this summer, all relating to SPFI EA82s with varying degrees of hesitation and other drivability problems. Please read, enjoy, and maybe even learn something.

 

Round 1: 1992 Loyale with horrible hesitation and bogging at all speeds and most throttle positions. The fuel pressure was a little low, so I replaced the fuel pump with little or no effect. Next, I tried replacing the fuel pressure regulator, again with no effect. After that, I started testing sensors and swapping them out with known good ones just to see if anything would change, and nothing made any difference. I also put on a new fuel filter. At this point, I was probably 20 hours and several hundred dollars into the project and had accomplished nothing. Eventually, I talked myself into going to talk to a local mechanic to see if he had any suggestions. He sold me a can of MAF sensor cleaner and suggested that I try it, just to rule out the possibility. So I sprayed the stuff on the sensor, started up the car, and it ran perfectly! I almost pooped myself!

 

Round 2: 1989 GL that ran okay up until about 50% throttle then had no power after that. It wouldn't even do 55 on the highway. Pulled the MAF sensor out, since that was the problem with the previous car, and it looked like it was covered in black hair! Keep in mind that this car had 277k on the clock, so I would expect some dirt in there, but this was impressive. Used the MAF sensor cleaner, and it got a lot better...the problem is still there to some degree, but the car will get up to around 80mph, and the hesitation isn't nearly as bad.

 

Round 3: 1994 loyale that came to me for a tune-up. After doing the plugs, cap, rotor, PCV valve, air filter, and fuel filter, I drove the car, and it was a little boggy, but more worrisome was the pinging under load even on flat ground. I rechecked the timing, which was spot-on, and then started scratching my head...what would cause such an issue? Then, just for kicks, I tried the MAF sensor cleaner once again. No more bogging, no more pinging. Wow.

 

In case you're wondering, I'm not being paid to advertise this cleaner. I had just never heard of this problem before this summer, when three cars came to me with the same issue. Hopefully, this will help keep somebody out there from going through the same frustration that I did.

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good catch. we need to bang together a thorough checklist of things to go thru.. on a Zcar forum there are guys who swear that theyve gone up to cars that have sat in a pasture for some time, powered and gassed them, run them thru all the FSM sensor checks until they checked out, and cranked them right up. We need to get a flow chart, or task list on EVERYTHING that needs checking done.. Im going to start mining the USRM for writeups that have already been done, and see if i can put a document together, like the USRM's HTKYS(ea82SPFI)A

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I'd be interested in helping with that.

 

And is MAF cleaner anything special? Or would standard brake cleaner/carb cleaner/etc work?

 

-=Russ=-

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I googled maf sensor and discovered that these guys are blamed for an amazing range of problems on different cars... Thanks Snowman!! Really good to know. DW

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I'd be interested in helping with that.

 

And is MAF cleaner anything special? Or would standard brake cleaner/carb cleaner/etc work?

 

-=Russ=-

 

I am not sure if brake cleaner is safe on an MAF,but they do sell special spray for cleaning them and I have used it several times with good results.Just about any parts store carries it.

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I'd be interested in helping with that.

 

And is MAF cleaner anything special? Or would standard brake cleaner/carb cleaner/etc work?

 

-=Russ=-

 

I would imagine that brake cleaner or spray electrical cleaner would be the most similar, but since the special stuff isn't expensive, I'd rather not risk ruining a sensor.

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Were there special instructions with the MAF Cleaner... like, "Don't start car immediately after spraying the sensor"?

 

good point. I used regular lightweight variant of glass cleaner mixed with a household degreaser. Worked very good. I did wait for quite some time before trying it out.Knowing it is part of a "hotwire" setup degreasing seemed common sense. :)

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on a Zcar forum there are guys who swear that theyve gone up to cars that have sat in a pasture for some time, powered and gassed them, run them thru all the FSM sensor checks until they checked out, and cranked them right up.

 

Slightly Off Topic:

 

I bought a 1956 star chief that had been sitting for over 25 years.

 

Changed the oil. Gas in the carb, fresh battery

 

 

Fired right up :D

 

Ran very well too!

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This is from my first hand experience but when it comes to dirty MAFs the best thing to use is CRC automotive electronic cleaner. It can be got at autozone for about five dollars. Its what I used when I had a dirty MAF from non-disposable air filters, the oil that comes on them collects on the mass air flow.

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boy i gotta check this one out... its such an easy inspection, and an easy fix.. and with my GL10 knocking hard on 140K i KNOW its gotta be nasty.... but a simple inspection would do.

 

as for any sort of guide, im basically going to start by plagiarizing (with credit given where its due) several USRM articles... Im sort of thinking of myself as an editor as much as author of this stuff, because alot has already been more than amply covered.. it seemed like a good idea, and anyone interested should PM me on it. Ive got a good idea in my head of what would be necessary, but i don't have the knowledge to fill all the gaps myself by any means. not to mention ive only ever owned one soob (that ran) so i might be a little ignorant on the MPFI and turbo systems.. IE clueless:-p but it seemed like a good idea, so let's see what can be done.

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I bought a 1956 star chief that had been sitting for over 25 years.

Changed the oil. Gas in the carb, fresh battery

Fired right up

Ran very well too!

 

Calebz is there a pic of that car around?? DW

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Just picked up a can of this stuff - CRC brand. I too am wondering if it's any different than Brake Cleaner.... I shall find out.

 

The guy at the parts store (some kid) actually told me I shouldn't waste my money on it. :rolleyes:

 

It *was* about $2 more than brake cleaner, but as I couldn't find a can of brake cleaner with a contents listing, I figured what the heck. Can't hurt too much to give it a whirl.

 

I'm experienceing a periodic rought idle, and some hessitation off idle with my transplant SPFI in the Brat, and I would like to rule this out. I did clean the existing MAF with like an entire can of brake cleaner, and it's nice and shiny.... so if this stuff helps I really will know it's something different.

 

GD

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eagerly awaiting your response. I pulled my own MAF today thinking of this thread, and was surprised to see the two hot wires off in that tiny chamber on the side... obviously someone wasnt paying a great deal of attention when he read how his MAF was designed. i thought they were stretched across the whole length....

 

those things are TINY!!!! i held mine up to the sun, (sorta) and got a good silhouette of my wires.. they seemed clear as could be, no oil residue or anything in the intake until after PCV tubing starts to come in... but since all I had was a can of seafoam deepcreep anyhow, I used that to blast it out.. no noticable difference here. if i see a good fine silhouette of two tiny wires, are they liable to be dirty enough to warrant additional cleaning? obviously if GD discovers much difference between the brakleen and this stuff that makes a huge statement right there..

 

we shall see.

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Huh - that's not the same stuff I bought. Mine actually IS Mass Airflow Cleaner. Same brand, but in a grey can.

 

My first stop at autozone I saw that stuff and passed it up as it said nothing about MAF's on the can.

 

GD

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Electronic cleaner is a gentler solvent than carb cleaner or brake cleaner. And it would be best to make sure it's all evaporated before starting the car.. especially as electronic cleaner evaporates slower than carb or brake cleaner.

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Huh - that's not the same stuff I bought. Mine actually IS Mass Airflow Cleaner. Same brand, but in a grey can.

 

My first stop at autozone I saw that stuff and passed it up as it said nothing about MAF's on the can.

 

GD

 

I just decided to relay the information based on my own first-hand experience. I have heard good things about the other kind also. I just went with it becuase alot of people on my tacoma forum had luck with it also. Made my check engine light go off.

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Well - it didn't help my periodic rough idle any. Hessitation may have been helped, but I can't be sure till I take it for a longer drive and get it on the freeway. I'm going to clean another one I have that has not been contaminated by brake cleaner. It actually says on the bottle of MAF cleaner that it's not as "harsh as brake cleaner or carb cleaner" and will not harm sensitive electronics. So I'm going to clean my untainted one and give that a try as well.

 

For the record it smells like watered down brake cleaner :rolleyes:

 

GD

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naturally, thats the exact stuff i had in the backseat of my car that i went to grab, only to find the can totally depressurized.. :mad: so I just used the deepcreep. while im posting on this thread, all the oily gunk i found in my TB when i removed the boot is a result of poor PCV valves, right? its not bad at all, just a little dark brown residue on the clean aluminum surface.

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I tried some MAF sensor cleaner on my 88 GL before a long road trip I'm still currently on.

 

It didn't get rid of some noise I have under heavy load, but it does seem to have helped my mileage. I have almost 400 miles on this tank, and it's still showing 1/4 tank left :eek: I'll know exact numbers later today.

 

Other than that, it seems to have helped a low speed stuttering I'd get when releasing the clutch from a start. Not sure though.

 

-Dave

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what octane do you use?? your noise might be "pinging," i had never heard it until i got the soob... when i told my brother it ran better on high test (hes the ASE mechanic who owned the car before I) he about smacked me in the head and told me, "I told you that, dummy!" if you use 87, try 93. i know it hurts, but I just had to do it, too. i bet it helps.

 

supposedly, if you know more than I do, you can also eliminate pinging thru timing adjustment.. but i dont know how to do that. you need to know alot about ignition to do that properly, and thats my biggest hole left :- )

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