Engine 'convulsing' below 1K RPM

[vendaz]

Hey people,

I have a '90 MX6 that just this week started acting up -- whenever the engine is running and the RPM gauge is below 1,000 RPM, the engine starts revving up and down really violently. I have to hold the brake and gas pedal above 1,000 to keep it from doing it, and even then it shudders.

Could this be a gas line problem? It drives fine when above 1,000 RPM.

[ricci]

i had the same problem...quick fix, tap the EGR solenoid valve with a hammer the engine will go back to the normal idle speed.
another way...spend $250 in a new egr valve

[vendaz]

Thanks for that, ricci. I hope it works!

[RoxysBrian]

I had the same problem and had to replace the hose running between my air flow sensor and the throttle body. You might have the same problem. Check the hose and see if there are any holes or cracks in it, if there are you can do a quick fix by putting duct tape on it, but I would replace it. I had to buy one directly from the Mazda dealership but it only cost about $65.

[vendaz]

RoxysBrian,

Thanks for the suggestion. Where is that hose, specifically?

[RoxysBrian]

Originally Posted by vendaz

RoxysBrian,

Thanks for the suggestion. Where is that hose, specifically?

Instead of explaining it out, I just took a picture of my engine and drew a red box around the hose you need to check. http://myweb.cableone.net/ebruff/smi...20engine-1.jpg

[vendaz]

Yes, that helps a great deal more than explaining it out. Thanks!

[vendaz]

RoxysBrian,

You take the prize, my friend -- exactly right. $35 for the part.

[RoxysBrian]

Originally Posted by vendaz

RoxysBrian,

You take the prize, my friend -- exactly right. $35 for the part.

You got out cheap. That hose new from the Mazda dealer cost me $65. Glad to be of help.