Motor had a massive intake manifold leak (Holly Flowmax), header leaks, etc. I took the Monster Miata ( '93, 5.0 HO, AFR 185'S, HOLLY SYSTEMAX, TRICK FLOW STAGE 1, 24LB INJECTORS, 75MM MAF, T5. 7.5 DIFF, 3:55'S) to a dyno shop to sort out all of the problems and tune the engine. All the leaks were fixed, a new ECU put in and the car dynoed 280 RWHP. However, now I have an ear piercing squeal at idle. I have disconnected the belts and the noise persists. One forum suggested it was a cam syncro sensor. Does a '93 have a Cam synchronizer sensor? Someone else suggested the EGR was the source. This was a problem which should have been fixed when the intake manifold was reinstalled.

Did my guy do a bad job? I can't seem to nail this problem down and I am afraid I could damage my motor.

Help please






whp

 

Welcome to v8miata.net

 

you can get the same noise from a distributor, the grooves get plugged up 93 doesnt have a cam sensor its only used with dis ignition.

 

Thank you. The dyno guy should know this. He had to remove the distributor to work on the intake. I hope he is not the problem. Thanks for the tip.

 

I had that type of noise from a BBK throttle body. I had to install an "adapter" on the IAC valve to get rid of it.

 

Tbone- thank you. I have a BBK Throttle body.
What kind of adapter was it? This is my first fuel injected car that I mess with. I hope the BBK is the problem. By the way thank you for all of the help you provide others. I am an avid reader of your advice. Once my engine is sorted out, a Kenne Bell is on my wish list.

 

I will try to find the part# for you.

 

The STAMPING# is F2PE-9F942-AA, but unfortunately it is no longer available from Ford.

 

Tbone, thank you. The squeal problem is the 6 year old BBK 70MM throttle body. At least I know I am not hurting something while driving. An attending cause may be a bad IAC not managing the idle properly.

 

Just found it in a new catalog. Mustangs Unlimited - The Premier Source for Mustang, Shelby and Cougar Parts and Accessories Hope this helps. It fixed mine.

 

I've heard of people drilling a small hole in thier throttle plate to make this go away. The OEM one has one. A small hole also helps to prevent "vacuum lock".

-Jason

 

Thank you for the suggestion.