So, I was able to score a local MAF from a friend while I wait for another unit to arrive in the mail. I, disconnected my Neg, installed and plugged it in, reconnected my Neg. Car fired up.. idled rough for a couple seconds, then smoothed out. I drove it around town (about 5 miles) and everything was cool. Happy Camper.

Then later I drove it to the Gym, where it ran perfectly fine. I left the gym, went to turn it on, it coughed, wheezed and died. Tried it again, same thing. Unplugged the MAF and it fired right up.

So I drove it home and tried disconnecting the neg to reset the ECM, checked to make sure my electrical connections to the MAF were clean (they seem to be), I plugged the MAF back in, started it up... and it wheezed an died.

This is where it get's weird.

SO, I unplug it, fire it up, wait for the check engine light to come on once it realized there is no MAF plugged in. I walk around the engine and while it is running, I plug the MAF back in and...

It wobbles for a moment, catches, and starts idling the same way it did when I first installed it and the Check Engine Light turns off
. So I took her out, and let her "relearn the MAF, Jet out to old Route 66 and stomped her around, getting her up to 100, throwing smoke out of the tiers on a hard acceleration, and she ran perfectly. Idled smoothly (At around 700 ish) and took me all the way home without issue.

So what on earth would cause the car to sputter and die when the MAF Was plugged in on start up.. then run fine assuming I plug it in after it's started up? I Have not tried to fire it up again.. cause I am hungry and wanna eat.

Pic Related, my Iroc out on Rte 66.

 

The plot thickens... IT has been starting up.. as long as I rev it a bit right away (like an old carbed car) than let it slowly settle in.

Still feels powerful though.

 

My prime suspect would be the relay socket connections, wiring, and relay contacts themselves. Both the MAF power and MAF burnoff relays are required to have good contact so the MAF analog signal can reach the ECM reliably, and so the MAF has consistent and clean power.

 

I think you are on to something here....

So, I pulled the plugs out of all these relays and found that the one that I highlighted ("MAF Burn Off Relay", found this image online so the names of the relays may be off.) was not only FILTHY, but also two of the wires were stripped back about a half an inch and touching each other. I cleaned the terminals and wrapped one of the wires in Super 88 and fired it up and it started and drove fine.

I am gonna try and start it in about an hour and see if it snaps to life again.

Thanks!

 

Nope. Same Thing. It idles like **** until I unplug the Maf to start it. Then it runs fine if I plug it in while it is already running.

I guess I could either..
A) Replace all the relays.
B) Add a 4 pole switch in series with the MAF sensor wires, and flip to "Off" on start up... and than flip it to "on" once the car is turned over.

 

If the relays are functioning properly they will do all that switching for you.

 

True, Vader... Very True.

So, I pressed all the connection is again, and wiggled the wires a bit, reset the ECM and now it's working again. Just went on a Beer run and she ran fine.

That said.. I think I will replace the relays.

Anyone have a great source for them? The oval ones all look the same Coil with a common, NC and NO connection. Same as the fan relay from the looks of it.

 

So,my car finally threw a code (36). So I was like.. "screw it".

So. in my 89 the relay closest to the passenger side was for the fuel pump, and the two next to it were the MAF Relays. I ran to O'Reilly's and picked up two relays for $35.00 (Power and burn off) and replaced them both.

Fired right up with no issues.

!!!!!!!!!!!!!!!!!!!!!!!!!Thanks Vader!!!!!!!!!!!!!!!!!!!!!!!

Also, I probably need to rewire my fuel pump relay as those wires are pretty bad going into the plug. But for now, I cleaned the plug ends and I got the Super 88 on there and that is keeping them isolated.

 

Those original relays did their job of switching low-level signals for almost 30 years before they lost perfect continuity. It would be impressive if everything on vehicles lasted 30 years.

It's not surprising that the relays were in a different order. That photo was from my '86, and has been spread all over the www without the disclaimer that positions may vary. The only way to verify is with the wire colors.

 

Here’s some part numbers for the relay
https://www.thirdgen.org/forums/elec...ump-relay.html

 

Wait, that was YOUR picture? LOL

To funny!

And I agree, this vehicle is in incredible shape for her age. I wish relays in my business would last half so long lol.