1989 maf relay questions
 

Three day ago I installed a new MAF Sensor. Solved my problems for 1 day. I coded a bad MAF relay power sensor. I changed both the power sensor and the burn sensor. Definitely not running as good as before I changed the last two sensors. any advice.
Thanks
Dan

Swap the connectors on the relays. The relays have the same part number so they will work in either position.

Note that ifl the MAF burnoff test fails the MAF wire will gradually get dirtier and dirtier. The car will run correspondingly bad as the wire gets dirty.

Which error code did you get?

Thanks Cliff,I put one of the replaced sensors back in the power switch. Engine smoothed right out, runs great. After running for two hours and setting for one half hour code 36 comes up with check engine light. puzzled. Im gonna pull the new burn off switch and add dilectric grease to the ports and replug.
Dan

Check engine always comes on after setting a while. Indication of what?

I had the same issue on my 88. It was my burn off relay. I was throwing the same code. Replace the relay and the code cleared. How it was explained to me is the burn off occurs A few seconds after the engine has been shut off. And carries on for a couple of seconds. If this fails it will throw the code 36. So you can be driving the car initially and have no code, shut the engine off and the next time you get in the car and started it will have the code.

That's how was for me and it stayed that way until I fixed it. I use the little dielectric grease also. Also as I had that code for a while until I figured it all out got parts at etc you may want to hit the MAF sensor with some cleaner.

Well Cliff we will see what happens. The wires to these two switches are crossed in my car, looks odd so I uncrossed them, they are now straight up and down. Same switches I did not see the harm. Back together and I will go from here and hope for the best.

Thanks for your advice. PS Are your wire sets straight up from below or crossed at switches.
Dan

Straight but as cliff said its the same relay on both sides.

...except in 1986 when they used two different relays (that are NOT interchangeable).

Thanks Cliff and Big Bird. Made the switch. Wires are straight up from bottom. Went for a hour run last night, so far all is well. But that has happened before.
Thanks you guys.
Dan

Seems to be fixed, no codes. Thank you both
Dan

Baileygo

Glad I could help. It's nice to be on the giving end of this forum for once ;-)

Big Bird 88, its back! Three days, its getting better LOL. Now what. could it be the new parts are not compatible?
Dan

Baileygo,

I'm wondering if the burn off is happening or not.

Go for a long cruise in the car. Some will tell you either get it up to temp or make sure it goes closed loop.

When you get home, leave it running. Pop the hood and disconnect the front part of the air cleaner assembly so that you can see the screened part of the MAF and the element inside.

Have someone shut the car off for you while you are looking at the element.
After a brief period of time (few seconds) the Element should glow to clean itself (kinda like a self cleaning oven)

There is also a way to test the actual relay too, but someone smarter than me will have to explain that. Basically you will apply power to it and take readings from certain pins.
There is a small diagram on the relay that indicates its function.

IF the burn off relay is working and the MAF is working (Idling good and burning as needed) then I guess the next step would be Ask Cliff if I need to replace the ECM.

Could someone tell me where these relays are physically located on an '88? I am not finding that in my FSM. Thanks!

They are two black plastic relays, mounted directly behind the battery on the drivers side on my 1988.

Thanks, Big Bird. Trying to figure out my Code 36. I finally found the sketch in my FSM but was still not sure that I was looking at the right relays. Was not expecting them to be so far from the MAF. Have a great day!