I have a MAF code that I can't clear. I took it to a dealer, and they told me it need a new MAF and computer. I already changed that. They said something about losing ground somewhere from my computer. I had them check burnoff relays and they were OK. I can't see spending the money again to replace these items. Can anyone help me out with my problem?

P.S. The year of my corvette is 1988.

 

The dealer told you it needed a new MAF sensor AND ECM??

Get a Factory Service Manual ( http://www.helminc.com/helm/product2...CG2CW3XM46DTCF ) and use the troubleshooting charts to track down the problem.

The FSM is money well spent

 

http://members.shaw.ca/corvette86/Code%2033.pdf
http://members.shaw.ca/corvette86/Code%2034.pdf
http://members.shaw.ca/corvette86/Code%2036.pdf

 

What code is it? 33 34? Just because you have a "MAF code" doesn't necessarily mean you have a MAF or Computer problem; there are other factors that can cause the computer to kick up a "MAF code".

 

I spent hundreds searching for my MAF code culprit, coupled with low RPM stalling.

The answer:

MAF Sensor CONNECTOR was in need of re-crimping.

That would explain why every test checked out, but operational failures continued.

 

byebyeL98: Decided to take your advice and ordered the service manual. It should arrive in 7-10 business days.

The car runs with no problems when MAF is unplugged, and it runs horribly when plugged in. You would think that the dealer would know the correct solution to the problem, but it seems they just want to get lucky replacing parts. Sorry, I can't remember the specific MAF code, but it was a MAF code and computer code. I'll have to scan it again to get the right numbers.

Thanks for the quick replies. I would appreciate anymore suggestions.

 

if you unplug the maf, the computer thinks the maf has failed, and picks a number that the limp home mode programming uses as a default.
That value will work for normal driving parameters, and the other sensor inputs becomes more valuable.
My ESC kicked out a code, and the idle was hunting, and I unplugged the esc module, and the car smoothed out.
I didn't drive it, but i figured the computer went to a default value, and regulated the engine with that.
There is a engine ground that goes to the ECM that is bolted to the back of the engine on one of the heads. I think it might be the right one.
then again, I was under the car looking up when I saw it, and it could be on the left.
The engine sits on rubber engine mounts, and the bolts might not provide that good of a ground.
If the injector ground is dirty or corroded, this might skew the total resistance of the injectors, and the ECM might pulse the injectors longer, or more rapidly until the oxygen sensor gives some feed back. happens in a millisecond, and it could possibly go lean and rich, lean and rich which would make it run bad.

 

Had a friends 88 with the same issues: one of the relays were bad, they are both the same PN, replaced both relays (behind battery on firewall) and problem resolved, also check wire connection at connector at MAF. They are only about $10 each...

 

I just got the car scanned with a TECH1 scanner, and it showed up as a code 36.

@ AGENT 86: I'm going to try the code 36 link you gave me and see what I come up with.

I'll let you know after the weekend what I find.

Thanks for all of the replies.

 

Also, the Code 36 could have been set due to a poor connection at any of the relays or the MAF sensor. Be sure that these connections and terminals or OK. A faulty MAF sensor should not be considered as the cause if Code 36 is set. Code 36 can also be set by high resistance in the relay contacts or connections. Be sure that these connections and terminals are ok.

 

I just read your posting and all the responses because I'm getting a code 36 from my 88. I removed both relays and checked the connections and the connector for the maf and all look ok. I'm planning to replace both relays this week and was wondering how you made out with your problem.
Thanks, Rich

 

Sorry it took so long to get back, I have been busy for the last few weeks. I figured the problem out. I followed the service manual on code 36. It brought me back to the computer being bad. I changed the computer, then I was getting a mass airflow sensor code. Then I replaced the mass airflow sensor and the burnoff sensor relay. The problem was solved, but I couldn't believe that the ECM and the MAF were both bad, so I put in my old ECM and it works fine. Thanks for all of the replies. I appreciate it.

 

Posted this in different topic,but seems it applies here also.

funny you mentioned this,i have a 85 vette and prior owner has the ford 24lb injectors on the car,plus the adj fpr.I was very shocked to see the psi at 55 with vac on and 50 with vac removed.So i lowered the psi to 45psi and figured this might stop the hunting idle i have,well when i shut the car off and went to restart,started and died.

So figured maybe the gauge was off or something with the computer.I then disconnected the battery,waited an hour and rehooked up battery,same start issue.Me being a ford guy,seemed like a mass air problem,so i disconnected the mass air and car started right up,better idle,but check engine light instantly came on.Reconnected the mass air while runnning,back came the hunting idle and almost ready to die out.So shut the car off,again same issue.

Now i figure maybe thats why the fuel psi was so high,to make up for the bad mass air,right or wrong??

But atleast the injectors are good,i can say the fms injectors are good to use.Now if my vette injectors go bad,i can take the injectors off my 95 cobra!! woo hoo!! Wish i could swap mass air. boo hoo......

 

....RE: Maf Problem.....purchase the maf relays and a new maf as your maf has taken a dump on you. the relays, although maybe not needed, could be "spares" as you WILL need them in the future either for a fp relay of maf relay.

 

......one can NEVER go wrong with a spare relay or two since you will need 'em in the future....