Recently purchased a 1990 525i. Only 80,000 miles. The car has not been driven for about a month. The owner made me aware that sometimes it would stall or run rough at times.
The car would run great most of the time, but when coming to a stop it would sometimes want to stall and I'd have to "flutter" the gas pedal to keep it running. Also, sometimes under hard acceleration, their would be a hesitation and the motor seemed like it had little power.
Well, now the car won't start. I originally thought it was the fuel pump, so I checked that first. The fuel pump seems to work fine, but the strainer sock was sucked up against the inlet and had some particles on it that were hardened. I imagine this would have prevented it from having good flow, but not sure if it would keep it from running. I then tried to start it with direct flow, bypassing the strainer. I pulled the gas line from the inlet at the engine, and it sprayed everywhere ... I'm pretty sure there is good pressure, but not sure what the actual P.S.I. would be.
Now that I am pretty confident the car is getting gas, I started looking elsewhere. I was told that the timing belt may also cause this problem. I took off the distributor cap and plug #1. I had a friend bump the ignition until I felt compression. The rotor postion matched that of plug wire #1, so I don't think it's a timing issue.
I then checked for spark. Very little at the plug wire. A visual inspection of the cap and rotor showed that it was in good condition and was probably replace not to long ago. Therefore, I decided to check the ignition coil. Holding the coil wire (I even tried a thick copper wire) an 1/8th of an inch from a few different grounded areas on the engine, then cranking the engine ... there was no spark. I only had spark when actually touching the wire to a grounded area. Even then, not much spark at all.
My question is: SHOULD I REPLACE THE COIL??? I checked the voltage to the two terminals on the coil, and they are getting about 10 volts each (while cranking). I'm not sure if this is the correct voltage or not? Also, I can't find any cracks or physical defects on the coil. Any advice? Is there anything else I should check before purchasing the coil?
Could this be a computer issue?