Which relay primes the fuel rails prior to startup. (i.e. key on) My car is hard to start sometimes, and the system does not prime when this happens.

 

Look on your firewall, to the right of the brake booster...you'll see 3 relays, two for the MAF and one for the FP...the FP relay is mounted in a different housing...almost sure it's the same relay as the others though...so you may be able to do a quick swap to see if that's your problem....if the relays are the same, don't leave it like that, or MAF issues will occur.

 

Thanks, I'll check it out today.

 

All the relays are the same. GM uses different part numbers on them so they can sell the FP relay for more money, because the car needs it to run. Seriously, I had a counter guy at the local dealership tell me that.

 

somebody is somebody because they aren't the same. The MAF sensor relay, MAF burn-off relay, and fan control relays are the same. However the fuel pump relay is an entirely different unit.

The Trickster!!!!!!!!!!!!!

 

Yeah, now that I think about it you're right. The fuel pump and the heater control relay are the same. They charge you like twice as much for the FP one though. I loot them out of junkyard cars whenever I see them. Since the car only really uses two different relays it pays to have spares, and if they don't work they were free!

 

That might be a good way to get them, but personally, I wouldn't advertise.

The Trickster!!!!!!!!!!!

 

"somebody is somebody because they aren't the same. The MAF sensor relay, MAF burn-off relay, and fan control relays are the same. However the fuel pump relay is an entirely different unit."

I found this odd because when i look up the fuel pump relay and the fan relay its the exact same part #14078902 on gmpartsdirect.com.

Update: Oh nevermind i see its a different number for the 1989 version. Still seems odd as I would think the relay would be similar between 1986 and 1989. If you notice its the same part for 1985 and 1986 tpis. I have a feeling even though part numbers are different in the newer tpi maybe they function identically.

 

They also changed the designs of the relays.

The Trickster!!!!!!!!!

 

Even if they changed the design for any reason they still should function the same. The wiring from a 1986 would be indentical to a 1989 model so i dont see why the relays wouldnt function similarly.

 

I didn't say they wouldn't function the same, I only said they changed the designs. Some were changed because of a newer technology and some were possibly changed to prevent confusion if several were placed in the same location like the fuel pump relay, MAF sensor relay, and MAF burn-off relay were.

The Trickster!!!!!!!!!!!!!!!!!!