C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

85 and 88 maf interchangeability

Thread Tools
 
Search this Thread
 
Old Oct 2, 2011 | 01:27 PM
  #1  
rsfire's Avatar
rsfire
Thread Starter
Intermediate
 
Joined: Aug 2011
Posts: 38
Likes: 0
From: Klamath Falls OR
Default 85 and 88 maf interchangeability

My car has been acting funny at low throttle levels, it sounds like it's backfiring out of the intake and has no power with minimal throttle. If i give it over 50% throttle it picks up and goes pretty normal; and once it's warmed up it drives more normal, but still does backfire out the intake a bit.
I'm throwing codes 32,33, and 34. Which two of those are for the maf sensor, I think that's my problem, and I know a guy who will give my his 88 maf for cheap if it will work. I've read on some posts that it will work and some that it wont, does anyone have an idea if it will?
Reply
Old Oct 2, 2011 | 01:59 PM
  #2  
87 vette 81 big girl's Avatar
87 vette 81 big girl
Melting Slicks
 
Joined: Nov 2008
Posts: 2,765
Likes: 5
Default

The calibration is different from the 1985 BOSCH C4 MAF compared to the 1986-87, & 1988-89 units.

Don't recommend using anything but the correct 1985 MAF for your car.

Bad driveability will likely result otherwise.
Reply
Old Oct 3, 2011 | 05:22 AM
  #3  
gerardvg's Avatar
gerardvg
Safety Car
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2009
Posts: 3,751
Likes: 275
From: Melbourne, Victoria, Australia
Default

Hi
I have a 88 MAF on my 85 vette it runs fine, the 85 had an analogue maf the 86 onward have digital mafs.
Google the numbers on the maf sensor and it will show what year it is for.I have been running the later maf without a problem, no codes either and the vette runs great
Reply
Old Oct 3, 2011 | 09:08 AM
  #4  
Midnight 85's Avatar
Midnight 85
Le Mans Master
15 Year Member
 
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Default

I've had an '88 maf in my '85 now for 7-8 years, no problem. This issue has been kicked around a lot on here and there are a lot of knowledgable people here but sometimes they are just wrong. If expertise in the matter means anything, the person who told me it was okay to run the '88 was none other than Gordon Killebrew, and that was in a face to face conversation with him.
Reply
Old Oct 3, 2011 | 03:11 PM
  #5  
rsfire's Avatar
rsfire
Thread Starter
Intermediate
 
Joined: Aug 2011
Posts: 38
Likes: 0
From: Klamath Falls OR
Default

thanks guys for the info, i'll give it a shot for sure and hope for the best. I'm glad to hear it runs in yours
Reply
Old Oct 3, 2011 | 03:11 PM
  #6  
rsfire's Avatar
rsfire
Thread Starter
Intermediate
 
Joined: Aug 2011
Posts: 38
Likes: 0
From: Klamath Falls OR
Default

Oh and was there anything else you had to do to the car or sensor, since you're switching from analog to digital? Or did you just plug in and go?
Reply
Old Oct 3, 2011 | 03:31 PM
  #7  
Midnight 85's Avatar
Midnight 85
Le Mans Master
15 Year Member
 
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Default

Plug & play. No mods needed.
Reply
Old Oct 5, 2011 | 09:17 PM
  #8  
rsfire's Avatar
rsfire
Thread Starter
Intermediate
 
Joined: Aug 2011
Posts: 38
Likes: 0
From: Klamath Falls OR
Default

alright, well I got the 88 maf today, i tried it and it's not working right. It idles super low, below 500 rpm. Once i accelerate it seems responsive and drives normally. Finally when I give it WOT it doesn't really pick up speed, it just seems hesitant or like my power is capped, and kinda backfires and stumbles. It also seems to run super rich, it reeks of rich exhaust and my fuel economy gauge is saying really bad gas mileage.

Does anyone have any idea what might cause this?
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-1

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-2

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-3

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-4

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-5

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-6

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-7

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-8

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-9

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
Old Oct 5, 2011 | 10:19 PM
  #9  
Midnight 85's Avatar
Midnight 85
Le Mans Master
15 Year Member
 
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Default

The symptoms you describe sound like what I experienced when the maf connector wasn't seated properly. I'm going to ask the obvious, please don't take offense, did you remember to plug it back in?
Reply
Old Oct 5, 2011 | 10:20 PM
  #10  
Pwnage1337's Avatar
Pwnage1337
Tech Contributor
15 Year Member
 
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
Default

Try unplugging the MAF and see how it runs.

If it improves, it could be the MAF burnoff module, or the MAF which you already replaced.

I have a MAF from my 85, but I was experiencing the same problems you state, so I just drove it with the MAF unplugged. Probably attributed to my car rocking a head gasket and leading to my engine build, but I was sick of it running like **** and just wanted to drive it. The engine was old and had seen much better days anyways. With the new engine I am going to be running a 85/87 hybrid setup, utilizing the MAF burnoff relays like the 86+ MAF cars.
Reply
Old Oct 6, 2011 | 01:32 AM
  #11  
rsfire's Avatar
rsfire
Thread Starter
Intermediate
 
Joined: Aug 2011
Posts: 38
Likes: 0
From: Klamath Falls OR
Default

yep, i didn't forget to plug it in, I even double checked haha. Although the 88 maf has been sitting around at the guys house for a few years, so maybe the wire in the sensor or the prongs in the connector got nasty.

I'll try pulling off the connector and seeing how it drives, I only unplugged it and revved it in neutral, it seemed to backfire and have an inconsistent idle, but i didn't actually drive it.
Pwnage,what is the 85/87 hybrid, are you referring to just the maf sensor stuff?
Reply
Old Oct 6, 2011 | 01:53 AM
  #12  
87 vette 81 big girl's Avatar
87 vette 81 big girl
Melting Slicks
 
Joined: Nov 2008
Posts: 2,765
Likes: 5
Default

I ruined my original 1987 BOSCH MAF while porting it out myself.
Broke the thin platinum wire.

Used a 1985 MAF on my 87 vert for 2 years.
Ran good but not quite the same.
Felt like less power much of the time.
No other changes made other than the installing the 1985 MAF.
Like ignition timing was being retarded 15 or 20 degrees.

Installed a 1988 MAF on my car a few months back.
Runs very strong.
Especially off the line.
More than I ever recall with my original 87.
I left the 1988 MAF stock with both screens intact.
Just wiped the entire housing clean with a damp rag.

Subject of 1985, 1986-1987, 1988-1989 BOSCH HOTWIRE C4 & F- body MAF's needs more scientific style research done.
With a laboratory grade Techtronics digital storage oscilloscope.
The best oscilloscope I ever used while still in college studying electronics tech.
Don't own that oscilloscope.
Looking for 1 to buy yet without costing $2K.
Cost was $15k something in 1987 I recall for that Techtronics Oscilloscope.
Dead on accuracy.

I suspect the BIN files were programmed in matched to each of 3 separate style C4 TPI style BOSCH MAF's.

I am no computer programming expert like others here on C4.

Electronics TTL circuits I recall much of.
I have a AAS in Electronics Technology too.

At least 2 OP AMPS (operational amp) circuits inside of those BOSCH MAF's.
Likely a signal converter & conditioner also.

Brian R.

Last edited by 87 vette 81 big girl; Oct 6, 2011 at 01:57 AM.
Reply
Old Oct 6, 2011 | 03:44 AM
  #13  
Pwnage1337's Avatar
Pwnage1337
Tech Contributor
15 Year Member
 
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
Default

Originally Posted by rsfire
yep, i didn't forget to plug it in, I even double checked haha. Although the 88 maf has been sitting around at the guys house for a few years, so maybe the wire in the sensor or the prongs in the connector got nasty.

I'll try pulling off the connector and seeing how it drives, I only unplugged it and revved it in neutral, it seemed to backfire and have an inconsistent idle, but i didn't actually drive it.
Pwnage,what is the 85/87 hybrid, are you referring to just the maf sensor stuff?
The 1985 cars used a special one year only "burnoff module" to power the maf and supply the burnoff function. 86+ years used a more reliable relay system. With my car, I bought an 87 harness, and sent it to Jims Performance to make it compatible with my 85's charging system/dash. It is going to use the burnoff relay system used on the 86+ cars. So its a half 85 and half 87 harness. Sorry for the confusion.

I remember when I was having an issue similar to this I would open the hood, and it would be running rough, but when I would drop the hood, it would clear up. Eventually I got a FSM and traced it to the burnoff module. When it was running rough, the slightest tap on the box would make it clear up and run great. It is not a reliable system, IMO.
Reply
Old Oct 6, 2011 | 04:01 AM
  #14  
Midnight 85's Avatar
Midnight 85
Le Mans Master
15 Year Member
 
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Default

It may be that the '88 maf has a broken wire inside of it, but try cleaning the contacts first. It may very well be that an '85 maf in a newer engine will not let that engine perform as well since the '85 is a dinosaur. GK and I did not discuss that, we only discussed upgrading an '85 to an '88. I have no issues whatsoever using the newer maf but like Pwnage says, the burnoff module is a poor system. I have already changed mine once and I have a spare just in case. I saw a new one somewhere the other day and they were asking $1300+ for it! If I were faced with needing one I would do something like Pwnage did and eliminate the burnoff module.
Reply
Old Oct 6, 2011 | 07:49 AM
  #15  
WW7's Avatar
WW7
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Default

Originally Posted by Midnight 85
It may be that the '88 maf has a broken wire inside of it, but try cleaning the contacts first. It may very well be that an '85 maf in a newer engine will not let that engine perform as well since the '85 is a dinosaur. GK and I did not discuss that, we only discussed upgrading an '85 to an '88. I have no issues whatsoever using the newer maf but like Pwnage says, the burnoff module is a poor system. I have already changed mine once and I have a spare just in case. I saw a new one somewhere the other day and they were asking $1300+ for it! If I were faced with needing one I would do something like Pwnage did and eliminate the burnoff module.
Before spending that much money on a new GM MAF sensor consider going to a Blowerworks maf like I did on my 89 Corvette..These use a Ford Mustang MAF blade type sensor that can be perchased for around $100.00 if they ever go bad. One of the nice things about this unit is if the sensor ever goes bad you don't have to replace the whole thing, you just replace the blade sensor that goes into the aluminum tube with 2 screws.You also don't have to worry about the MAF burn off module anymore, the new unit eliminates there use..The whole unit including the housing, new plug, and instructions is $299.00 for the smooth tube with sensor or $399.00 for the tube with L98 adapter plus the Bin files for your car.The cheapest I have ever seen a new GM Bosch maf is $799.00, and that's if you can find one...WW

Go to the site below and click on "GM L98 MAF Sensor"

http://blowerworks.net/

Last edited by WW7; Oct 6, 2011 at 08:03 AM.
Reply
Old Oct 6, 2011 | 07:57 AM
  #16  
87 vette 81 big girl's Avatar
87 vette 81 big girl
Melting Slicks
 
Joined: Nov 2008
Posts: 2,765
Likes: 5
Default

Originally Posted by Midnight 85
It may be that the '88 maf has a broken wire inside of it, but try cleaning the contacts first. It may very well be that an '85 maf in a newer engine will not let that engine perform as well since the '85 is a dinosaur. GK and I did not discuss that, we only discussed upgrading an '85 to an '88. I have no issues whatsoever using the newer maf but like Pwnage says, the burnoff module is a poor system. I have already changed mine once and I have a spare just in case. I saw a new one somewhere the other day and they were asking $1300+ for it! If I were faced with needing one I would do something like Pwnage did and eliminate the burnoff module.
I have the 85 BOSCH MAF Sensor yet Chuck.
I will hang onto it in case You need it.
Its de-screened by me.
But the housing I did not port.

Came off a '85 C4 You brought in at "V2V" when I 1st met You & Jason.

Not worth $1300 to me. ??
Crazy.

Need an all original low mileage ZR-1 rear diff assembly.
Factory installed batwing be awesome too.
Not for me.
For a special C4 ZR-1 Racecar that runs a very cool & fast flying American Road Race.
90 miles flat out.
I would appreciate if You & Jason keep an eye out for 1 or if another wrecked C4 ZR-1 comes in.
Year is not important.
Just from a ZR-1.

The $$$ is good to take it off your & Jason's hands.

Brian R.

Last edited by 87 vette 81 big girl; Oct 6, 2011 at 08:17 AM.
Reply
Old Oct 6, 2011 | 09:01 AM
  #17  
Midnight 85's Avatar
Midnight 85
Le Mans Master
15 Year Member
 
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Default

Thanks for the offer on the maf but I think I would switch to speed density if I ever needed one. I have tuned port on my dd El Camino too, it is run by an Accel Gen 6 system and is speed density. I'm not crazy about the Accel unit but I do like the speed density. I'm not going after wrecked Vettes any more, too darn old to be crawling all over underneath a wrecked Vette looking for solid places to tie it down.
Reply

Get notified of new replies

To 85 and 88 maf interchangeability

Old Oct 7, 2011 | 03:15 AM
  #18  
Cliff Harris's Avatar
Cliff Harris
Race Director
15 Year Member
 
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Default

I checked in the PDF version of the parts microfiche and came up with these numbers:

1985: 14971243, Delco 213-162
'86 - '87: 14094712, Delco 213-163
'88 - '89: 10055877, Delco 213-161

I have no idea what the differences are between the various years/part numbers.
Reply
Old Mar 1, 2017 | 06:33 PM
  #19  
85vegasvette's Avatar
85vegasvette
Racer
 
Joined: Oct 2013
Posts: 483
Likes: 19
From: las vegas nv
Default

i acquired an 88 maf from a forum member based on reading these threads, my 85 did not take well to the 88 maf , if it could throw up i think it would have...just my input and experience
Reply
Old Mar 1, 2017 | 07:45 PM
  #20  
Bwbob's Avatar
Bwbob
Instructor
 
Joined: Oct 2015
Posts: 134
Likes: 6
From: Osceola WI
Default

Originally Posted by 87 vette 81 big girl
I ruined my original 1987 BOSCH MAF while porting it out myself.
Broke the thin platinum wire.

Used a 1985 MAF on my 87 vert for 2 years.
Ran good but not quite the same.
Felt like less power much of the time.
No other changes made other than the installing the 1985 MAF.
Like ignition timing was being retarded 15 or 20 degrees.

Installed a 1988 MAF on my car a few months back.
Runs very strong.
Especially off the line.
More than I ever recall with my original 87.
I left the 1988 MAF stock with both screens intact.
Just wiped the entire housing clean with a damp rag.

Subject of 1985, 1986-1987, 1988-1989 BOSCH HOTWIRE C4 & F- body MAF's needs more scientific style research done.
With a laboratory grade Techtronics digital storage oscilloscope.
The best oscilloscope I ever used while still in college studying electronics tech.
Don't own that oscilloscope.
Looking for 1 to buy yet without costing $2K.
Cost was $15k something in 1987 I recall for that Techtronics Oscilloscope.
Dead on accuracy.

Like this?



Brian R.




Or this
Reply



All times are GMT -4. The time now is 06:15 PM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE