Engine missing funny noise around the smog pump sounds like a jake brake when i pull the air filter but as quick as the noise shows up it goes away engine runs great but then misses and noise comes back looses powere during noise

With the engine running pull the fuel pump relay and see if the sound goes away. The engine will run until it dies of starvation. I'm wondering if your fuelpump it making excessive noise. Also, check fuel pressure before and after the fuel filter to see if there is any restriction in the fuel line.. hope this helps

Somtimes drive belts can get a hard spot in them causing all sorts of funny noises. If the noise is related to engine revs, try removing the belts to see if it goes away

It most likely is the air injection pump, The bearings may be going out and that is why it is only doing this when cold

lower engine mount by the sound of it ,body to engine underneath at the back ? I have one of these cars but a 205 1988 great little car for carrying my tools around

The smog pump has plumbing coming off of it which some is made of metal. The acids in the smog that is release through it eats away the metal in time causing leaks that will cause this noise

Hello, You may have a bad brake booster, there can be a check valve in the feed line to the booster. You need to have a pressure check done on the brake booster. Be careful not to use any chemical which can dissolve rubber or plastic if you use a spray around the booster. A water spray may indicate a leaking booster if you test it with the engine running. The rpm will change from a leak.

The ABS system should show a "check light" if it is malfunctioning. The modulation inside the brake unit possibly could make noise.

The Traction control, if equipped, can activate a control valve in the intake system to limit engine RPM. When this system works, it shuts off intake air to slow down the engine when the system detects slippage in the rear wheels. If you have a toggle button on the dash to switch off the Traction control, turn the sytem off and try driving it and see if the noise goes away. Debris in the rear rotor "drum" brake could possibly blind a wheel sensor counting the revs and activate the Traction control

Idle speed control "motor" is a type of intake air control used to smooth out the engine. It operates in a air chamber and its the last thing I can think of that even remotely could make a noise.

pull air filter out and start car. does it whine? that should answer that question. i think its a pulley,power steer pump,water pump, idler tension. while engine is running be very careful and try to listen and look at any of those and see if any wobble or squeal, also make sure the belts are tightened and not slipping on alternator pulley. also could be the alternator whinning.with the hood up and car at cold idle i'm sure you will be able to diagnose.

Spray the intake manifold on cylinder number where it bolts to the head with intake cleaner and see if the rpm's change and the miss goes away temporarily.There was a problem at the factory with the intake gasket being creased on cylinder number 1. This issue tends to be a lean misfire issue.

Check around the air filter box to see if there is a vaccume line knocked of,there is a vaccume routeing sticker under the hood if you need help.I would take the car back to where you had it serviced and ask them for help if you can't find the problem on your own.

You are luckey it happen at idel. Open the hood and put your hand on various sheetmetal and plastic parts until the noise goes away. When you determine the piece at fault, see if some screws are missing or if it can be repositioned to avaoid the noise. Does not sound serious.

Good Luck