Car hesitates under throttle

[burkem]

I recently picked up a 1987 325is. The car ran pretty well but didnt like to start first crank. It would take about 5 seconds to turn over and the idle wasnt great. After reading on a few forums I decided to clean the CPS. I removed it and sure enough it was coated in gunk. I cleaned all the gunk off with a rag and reinstalled it. Now the car still idles poorly and it hesitates badly under throttle. When I put it in gear and try to drive it, the motor kinda stops and will stall out. The only way I can get the car to move is to rev it real high and let off the clutch. The previous owner said he replaced the entire fuel system from the tank to the injectors. He replaced the spark plugs, wires, rotor, cap. All the good stuff for an old car. Im not sure what cleaning the CPS could have caused but if anybody has advice on what to do or where to go from here, please share. Thanks.

[ELVA164]

You should get a smoke test done to check for vacuum leaks, although it could be possible that the CPS is worn aside from being dirty. Start there, but other possibilities are the AFM or ECU.

[e30construction]

+1..also cleaning a worn out cps will do nothing if the magnestism is going out

[Killacortes]

Check your coil too.

[burkem]

Would checking the resistance confirm if the CPS is faulty? Also, the car ran ok prior to cleaning it, now I cant even drive the car its so bad. The only other thing I have done is removed the seats and carpet in the car but I dont think that could be related.
What exactly am I looking for when I check my coil?

[dnguyen1963]

Don't waste your time and energy until you have a smoke test done!

[burkem]

I think Im gonna try and build my own smoke tester and perform the test at my house. Has anybody done this and have any advice?

[dnguyen1963]

You can buy a smoke machine (for party) from Amazon for @ $40. Have the smoke pump into a large closed plastic tub. Place a fish tank air pump in the tub to pump the smoke to the engine. You need to plug the exhaust and the air intake boot to find small leaks. There are other DIY for cheaper smokers on the internet. Or, the best bet is to find a shop that can perform a smoke test (for about $100).

[burkem]

Okay, I have further determined the problem. It only runs poorly when its cold outside or before the car warms up. I drove it today a few miles after it was warm and it ran ok. I know the sensor that sits in the coolant tank on the passenger side of the bay is no good. Also, a few other questions I have. The clutch squeaks when releasing it to take off in first gear, very odd IMO. Also, the steering squeaks when I turn the wheel at low speed, no idea why.

[jlevie]

A smoke test of the car should be the first thing done. Followed by repair of the leaks the test reveals.

[bddog]

Why does everybody keep telling people to take it to the shop for a smoke test?
I never take my vehicles to the shop.
For half the price of a smoke test alone, I can purchase all new vacuum hoses, boots,etc.
While at the shop, I suppose you would have them fix the vacuum leaks. Just try to keep them from charging you for the test alone. How about a tune up? Have them change your oil.
I hunted down and fixed my vacuum leaks. Fixed whatever has come up for eight years without a smoke test. If something is old and brittle, replace it.
For the OP: There is a boot between the throttle body and your air flow meter. I would look at replacing it. It can have cracks in the folds. Myself, I would just purchase all new vacuum hoses and lines. Start fresh. These cars are prone to vacuum leaks that effect performance. Thus, the "smoke test" folk.

[dnguyen1963]

Vacuum leaks can come from many other places besides hoses and lines.

[mrgraphics]

Mine hesitated from idle to acceleration. Turns out the bitch tube had an air leak due to a worn o-ring. Only doing a smoke test found it. I wasted months chasing it. What is your time worth?

[bddog]

Months? Wow. Sounds like you need to take yours to the shop for an oil change. All men are not created equal.