Well I was driving to work and a horrible sound came from my engine compartment, it was screetching and then it smelled kind of like burning electrical instulation. I was only about a block from work so I made it there with the noise coming and going, seemed to go away if I reved the engine up. I popped the hood and saw that the belt for the alternator/air pump was broken in half.
Not having my tools with me, or another belt, I just waited till work was over and tried to start it up. To my surprise it started fine, although the gauges were all wacked out except for the speedo and tach. It actually seemed to rev faster, but it had less low end power. My second turbo is out anyway so I didn't push it hard but I drove the 11 miles home with no problems. My aftermarket temp gauge started reading really high even with the fans on toward the end but when I popped the hood it was really cool, like it feels when I run at 76C or so. So then I replaced the belt but when I started it up it squeeled like a stuck pig and a little bit of smoke came out of the air pump pully area. Did my air pump bearings fail and cause the belt to break? Thanx!

 

Mindphrame's air pump made am intermittant chirping sound before it seized. You can test for a seized air pump by unplugging the grey two-pronged electrical connector that connects to the air pump and then starting the car (you should have a belt on your alt/airpump pulley). If you can't find this plug, then I can post a picture for you. If you hear no squeeling sound then plug in the connector while the car is still running. If you hear the squeeling sound, then your airpump has seized (quickly unplug the grey connector, BTW). This electrical connector supplies current to the air pump's magnetic clutch. The ECU disengages the magnetic clutch when the car is above 3500rpm or somewhere thereabouts, so that's probably the reason you didn't hear the squeeling when you revved the engine. The car started and ran fine, because it was running the electrical system off of the battery. My roommate's '88 prelude lasted at least four hours on just the five years old battery. However, his car does not a quarter of the electrical systems found in the FD.

 

Yes, my air pump was going when I first bought my car. It would intermitantly stall and burn the belt and i'd notice white smoke rising from the hood. I actually have a Greddy kit installed but did not know the size nor where to get it. The local race shop close to me didn't either and refused to hookup the Greddy kit bypassing the air pump and I was forced to buy a used one not knowing how to get around it.

See if it will still spin freely with the belt connected but the pump unpluged. Doing this or the Greddy pully kit will shorten the life of your Cat' though (assuming you have one).

 

That belt drives the water pump so that's what caused such high temps when driving it home. Check to see if the airpump spins freely with the connector disconnected.

 

Thanks guys, I'll check that a little later today. Sure glad I'm running Evans NPG+ !!

 

hey phil, it sounds like 100% airpump failure.
this occured with my r1 because i HAD 2 k&n cones sucking hot engine air. i believe i got a 28-29.5 inch belt and bypassed the airpump, and took it out because there are no emisions tests in FL.
p.s, i went on the inside of the water pulley, if i had to do it agian i would go on the outside (passenger side) of the pulley with a 30-32" belt.

 

did you check to make sure the pick up for the crank angle sensor didnt get bent??it can happen when you throw a belt....it will be down on power and possibly backfire when you bring it up on boost....just a thought ...mike