'87 GN MAF - How do you tell if it's good, can I clean it?

C

copo

Member
Joined
Apr 25, 2003
1987 GN:
Is there any way to test the MAF? Mine got wet abit from the weather and it feels like I got a bit of a surge feeling at 50mph and 55 mph then when I reach 60 mph it sometimes feels like the tranny goes into 4th when it's already in 4th. Last week I topped the tranny fluid to the full line. It was 1/2 down from full.

I do see that the circuit board has a protective coating on the MAF.

What do you guys use to clean the circuit board. Is electronic cleaner in a spray can ok?

Is there something on the market that can replace the MAF? The last one I bought in 1990 was one of the last 2 in Canada from a GM Dealer and they aren't cheap. Anyone else make them and work just as good as the factory ones?

Do I have a MAF problem or a tranny problem? I have 115,000 miles on the car.

I changed the tranny fluid and filter once when the service book stated.
I changed the plugs last Sunday.
I changed my oil/filter 2 weeks ago.
I changed my fuel filter last summer.
I went back to the stock air filter in case I was getting oil on the circuit board from the K&N filter as stated in my other post today, so maybe I need to clean the circuit board?
I've added injector cleaner to my last gas fill up of Sunoco 94.
 
Hard to tell, but it sounds like it may by the TCC solenoid locking and unlocking the torque converter. When cruising at 55mph, tap the brakes while keeping your foot on the gas. The RPM should climb 100 - 200 then drop back down. If it doesn't you have a TCC issue which is a fairly easy and cheap repair.

If you need a new MAF, you best bet is to get a translator or translator + and use the newer 3" or 3 1/2" MAFS from GM.
 
I presume the TCC solenoid is on the tranny. Where? Any pics emailed to me would be appreciated and instructions. Is it just an unscrew and screw in? Will there be any fluid leaks when the TCC is removed?

And, excuse my ignorance on the Turbo cars again, I'm usually working on SB Chevys, but does a translator pretend to act like a MAF? Will the computer be confused?

Are the new 3"-3.5" MAF the same dia for the connections to fit as the OEM? Any apart #'s would be good if I need one in the future. Thx in advance.:eek:
 
After going into the tranny section I read about the TCC problems.
I also notice that after I get into 3rd gear and stay around 30mph, it feels like I'm in 4th. I have to speed up to wake it up from a low rpm crawl.

Before I drop the pan and replace the TCC solenoid, how do I check to make sure my brake pedal is adjusted properly for the TCC to operate correctly?

Does this sound like a TCC problem? I haven't done the brake/gas pedal test yet.
 
Mark, the MAF sensor does have a protective coating over the curcuit. DO NOT try to clean it. Things as small as high concentration of deisle fumes have been known to kill a MAF sensor because it would break down the protective coating and expose the electronics and ruin them.
The 50 to 55 thing sounds like it is going into lock up more than anything. You may just have an issue with a weak TCC solenoid.
When you start getting this surge thing try lightly putting your foot on the brake pedal (will cancel lock up) and see if the surge goes away.
Let us know what you find.

Mark
 
Originally posted by copo
Does this sound like a TCC problem? I haven't done the brake/gas pedal test yet.
Click to expand...

do the test, it's simple easy and will rule out the TCC sol.
 
About a month ago I adjusted the white switch on the end of the steering column because my back up lights were not working. Now they work. I hope this was the correct switch.
Here is a pic.

bkup_switch.jpg


Here is a pic of the other switches. I can pull back the brake pedal about 1/8" before it rests on the plastic switch case. Here is a pic.

switches.jpg


Does this need adjusting, if so how? By removing the wires and turing in the threaded holder closer to the brake pedal shaft? When do I stop? If this 1/8" is ok then I'll leave it.

I did the brake test on the highway without lifting my foot off the gas and the RPMs climbed 1 bar on the OEM tach. So does this mean my TCC is ok or is bad? Thx in advance guys.
 
oops, I did the test just by driving on the highway. After 60 mph it doesn't do it. So what's my test results mean from the 1st test? I'll try holding it in the mph band where I notice the surge and do the test and let you know what happens.
 
I just went to the car wash and also sprayed the underneath and went for a test drive to the mph area below 60mph where I get the surge. Well this is weird. I couldn't get it to surge. I wonder if I have a loose wire under the car at the tranny, cause I wash the underside each time I spray it at the car wash to keep the salt off it in the winter.

Anyways I'll have to jack it up tomorrow to see if the wires are on snug. BTW, it the TCC needs replacing, can I still drive it or will I do any damage to the tranny/torque converter? It's still winter here and too cold to crawl under the car.

Can someone explain to me what happens to the tranny and torque converter when you say it's locking and unlocking. Is locking when the tranny stays in a gear and unlocking is when it upshifts or downshifts into a gear?
 
By "locking" I am refering to the torque converter locking up and not slipping like it usually does or does in most mid 1980's and older cars. If your converter stays locked it will seriously hurt performance.
You may have a TCC wire problem. If you unplug the connector - you don't need to drop the pan - the surging should go away but you converter will not be locking up at highway speeds. I'm not sure if there is any potential for long term damage by doing this.
Replacing the TCC solenoid is a very easy fix - it's just a tranny fluid change with the addition of 2 or 3 bolts and 1 plug connector. I'm mechanically DE-clined and I did it.
 
a l/u converter has a clutch in it that the tcc sol engages it at cruising speeds for better gas mph. It is just like a regular clutch only electronicly controled and applied. If it stays locked you would feel the eng. being loaded down (lugging) not appling would give worse mph and can lead to over heating. The tcc sol. is a cheap easy replacement, I would recommend replacing it with the next fluid change, new aftermarket are much better than the original ones installed and are about $20-5.
 
I just changed the fluid and filter this past summer. Shucks.
Do you guys recommend installing a drain plug, or would it be another area to worry about if leaks start?

Next time the car surges and I do the test with the gas pedal and brake pedal. If the surge goes away, does that mean the TCC is good or bad? And what is the part called when I go to purchase one? A TCC solenoid?
 
Originally posted by copo
Next time the car surges and I do the test with the gas pedal and brake pedal. If the surge goes away, does that mean the TCC is good or bad? And what is the part called when I go to purchase one? A TCC solenoid?
Click to expand...

Anyone? If I do the test and the surge goes away what's it mean? If it goes away does that mean the TCC needs to be replaced?
 
If the surge goes away when you lightly hold the brake pedal, there is a very good chance the TCC solenoid needs to be replaced. Any GM dealer should be able to get you the part - yest it's a TCC Solenoid or Torque Converter Clutch Solenoid. I would bet that one of the vendors on this board like PTS carries the part.
 
Just go to a parts store and buy one for a 700R4. It is longer and a better solenoid. You will get some shims with it that you must use. Other than soldering it in place, it's an easy job. Part should be around $20 - $25. Is the surge you are experiencing like a hiccup? If so, I had a MAF degrade just like that. Get another for a spare if you can and keep it in your trunk. Eventually it will go out one day and leave you nearly stranded.
 
Originally posted by John Larkin
Just go to a parts store and buy one for a 700R4. It is longer and a better solenoid. You will get some shims with it that you must use. Other than soldering it in place, it's an easy job. Part should be around $20 - $25. Is the surge you are experiencing like a hiccup? If so, I had a MAF degrade just like that. Get another for a spare if you can and keep it in your trunk. Eventually it will go out one day and leave you nearly stranded.
Click to expand...

Yup, it's like a hiccup or like there's a head wind for a sec. BTW, I'm on my 2nd MAF sensor too. The last one I bought from the dealer was 1 of 2 left in Canada about 9 years ago. Does anyone know if GM stocks them again? If not where do I get one? I know a bud that has a '87 GN so I'll ask him if I can test it.
 
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