When I start the car the rpm's bounce up and down and if I press the gas it losses power it doesnt stall anymore but the rpm's drop off and returns when I let release it. Anyone have any idea what is going on with that or have/had the same problem and what did you do to fix it?

 

Vacume leak? Check intake , all the rubber elbows - intake parts. something is cracked or leaking.. you can spray carb cleaner on areas and see if the car stalls that would be the area where the leak is. Or starter fluid can be used.. but its very flamible so sparks can ignite it..

 

thanks for the info.

 

Vac leak fixed but it still doing the same thing. the car isn't stalling but rpm drop when i press the gas. can this be from my tps sensor (throttle valve switch)? and its hard to start cold. I tested the tps sensor with a multimeter and it seems ok but i dont know what the omh reading should be at closed and full open. Can someone help?

 

does anyone have a tps sensor (throttle valve switch) I could get for cheap? the one on the primeary thottle body. i dont have ASC-T so I don't need the secondary TPS sensor I have one that someone else gave me but it isn't the one that i need.

 

Maf?

Go on bimmer forums Tr's bimmer section is ghost town

 

GO to LKQ or Cophers U pull. They will have the parts there used in the yard.. Last time I was there there were 3 BMW e34 525s They should have the same TBS.. But the Air Flow meter - wire may vary. Just look at the pins and plug to match.

The First thing I would do is Unhook the Oxygen sensor, this should put it in a loopback mode. I have had a bad OX sensor cause the car to stumble in the past.

I would also go to Harbor freight and get a fuel pressure guage.. So you can check the pressure in the fuel rail and check the return line. I have had the same symptoms due to to much pressure. the return line was kinked .

When all else fails there are some good shops in Tampa that are very good with BMWs. I just had to take a car to Cars and Concepts for a Wiring-ECU reprogram.

 

un hook the maf does anything change? If not maf needs to be replaced

 

I just replaced the MAF, TPS, Fuel Pmp & Filter, Wire Harness, Plugs, Battery, ACV & Hose. Today I started the car and removed the air filter but left the MAF sensor. I then used my hand to cover half of the opening to the MAF and the car began to run smooth. I could also push down on the throttle and the car rev as if there was nothing wrong. I also uncovered the MAF and when I spray carb cleaner in the MAF the car would rev but if I puhsed down on the throttle it would stall. Does that sound like it isn't getting enough gas? Fuel Pressure Reg. was my next step and injecters. I just wanted to run this by you guys here and see if I'm looking in the right direction. I also unpluged the O2 sensor with no change. And when I unplug the MAF the car stalls.

 

Problem fixed.... Someone cut the hose to my fuel pump.