mike 1985

i downloaded WINALDL friday and was moniyoring the car. it wouldn't read any sensors or the dash ?? then the car just shut off, it restarted with a check engine light but still idled just fine. As i started to drive away the car was stumbling off idle,wouldn't rev up and was slightly backfiring. I pulled the codes and got a 33. In my haynes manuel it says to check MAF connections and could be a bad MAF. It also to replace MAF, Burn off relay, and ECM. I replaced the MAF and ECM and it still has the same problem. None of my local auto parts stores have or can find what a burn off relay is. ??? Does anybody have a pic of this? It's supposed to be under the pass side dash on an 85? Also where can i get one of these?


And the last thing i checked was the red wire at the MAF and it does not light a test light as the book says it should. The SES light goes off and car runs with the MAF unplugged.

Any suggestions please?

vader86

The Code 33 is usually the MAF relay, not the actual MAF. All i know is that its buried inside the passenger dash, none of your parts stores has it and cant order it?

Otherwise order from GM.

mike 1985

thanks i spent 2 hrs on my back under the dash and may have found it, then again i don't know what it looks like, does anybody have a pic of it ?

frank moran

85 does not have a burn off relay it has a burn off module behind the bread box, before you go there check that it is functioning by
discinnect the MAF latches
ignition on
ground ALDL and terminal E
turn ign off and witin 4 seconds observe the element in the MAF sensor it should light up, you need to be quick about this as it burns off quickly, have it all set up for this est and it is quite easy. The module was used on 85 vettes and F bodies with TPI...

mike 1985

thanks. i just called GM and they said it's a module and it's $900...is this right? And does anybody have a pic of this thing?

Thanks again

MrNuke

It kidn of looks like your ECM, just slightly smaller. same sliver aluminum cover. You can't miss it. I would not replace the Burn off Module though.. Cheaper to just upgrade to a '165 ECM which uses actual smaller relays instead of the expensive module as the '85 does..

mike 1985

the only box looking deal that i saw under there was a black sq box with a good sized plug in it. How far up is this module? Do you have to take the bread box out to get to it?

Swapping ECM's sounds like more than i can handle, is this a unplu one, plug in a new one or more involved than that?

Bluevette85

Did you use a 10k resistor between pins A+B on the ALDL?

The Burnoff module is behind the breadbox. It cannot be seen from underneath. You have to remove the dashpad to see it.

The Haynes manual cannot help you diagnosis a 85 maf problem. I will scan the diagnostic procedure for your trouble code from my shop manual and send it to you later tonight.



[Modified by Bluevette85, 1:10 PM 6/16/2003]

frank moran

to do the test I mentioned in my prior post you need to jump to the E terminal on the ALDL to test the burn off mod, not A and B but A and E. also this piece is used on 85 F bodies so there are a lot of them around. As Blue said you have to remove the crash pad or bread box to get at it. ..size of a cigarette pack, silver box. Before you start spending money do the test, you may not need it..

LD85

It is attached to the aluminum frame directly behind the bread box, email me if you want a pic.

mike 1985

thanks everybody for all your help.

Frank i will test the module tonight when i get home from work.

And does the 10K resistor between A&E make the car go into limp home mode?

frank moran

dont know about the resistor, the top row of the ALDL reads
GFEDCBA, CONNECT A TO E , ign on, connect A and E, shut ign off and quicly view the inside if the MAF sesnor, you should see it light up, the wires will get red hot. if so the burn off is working..

mike 1985

thanks frank i'll do this tonight. If it lights then the module is good and if it doesn't then i'm assuming it needs a new module?

frank moran

not until you check the wiring next, to clear up my directions, have the ign. on then connect A and E , shut it off then check....... I dont belive a burn off Mod will set a 33 on an 85, but it's easy enough to check.. I would confirm the above, clear the codes, drive it and see if it comes back. Does it have a hard failure, light on all the time?

mike 1985

yes the light is on all the time, prior to this i used to get a light when idleing, but would go off when i starting driving. I'll try this, then try to drive it again. I even swapped the ECM and still same problem and code ?

Unfortunatly i don't have access to the forum from home so i won't be able to get back till tomorrow.

I was really dissapointed the last two days as they were the nicest of the year so far and my car wouldn't run, but i feel better today after all the help and advice i hope i can get it figured out soo with your help.

thanks again
Mike

LD85

Mike just for the heck of it, and if you have'nt already, pull the MAF connector plug and make sure that none of the connector pins are pushed back into the plug making intermittment contact.

Just a thought!

mike 1985

thanks i already checked that, all is good. Also if i unplug the MAF the SES light goes off and the car runs( like a 6cyl, but it runs)

Bluevette85

I just emailed you the Code 33 shop manual pages.

CMYC4GO

Your burnoff module is directly behind the breadbox, and yes, you have to remove the breadbox to get to it, and it is a royal PITA. It is silver, and looks just like a smaller version of your ECM. If you're going to pull the breadbox off, you might as well get the replacement flat dashplate ($49) from any of the Vette Catalogs. It will give you easy access to the dash guts, and it looks better too!

mike 1985

Frank, i did the test last night and the wire did not light. I also noticed the 10G fuse was blown in the GAUGES position of the fuse box. Don't know where to go from here.

Blue vette, thanks for the info, this may be beyond my capabilities, but i can show it to a couple friends.

I looked through the haynes manuel and it doesn't show how to remove the bread box, does someone have instruction for this and a web site to order the better one, also will it just bolt in or does it need modified.

And my last question, which is coming clearly out of frustration, has anyone every just put a carb,intake and reg distributor on an 85?

thanks