View Single Post
  #4  
Old 10-11-2014, 01:21 PM
oldtrucker's Avatar
oldtrucker oldtrucker is offline
BMW Mech (70's) Germany
 
Join Date: Jan 2014
Location: San Diego County
Posts: 131
Quote:
Originally Posted by liquiddog View Post
Also should mention I replaced the mechanical MAF sensor around the same time. I assume on the m104 it is a more typical electronic MAF sensor but it serves the same purpose. I had a 2000 4.6l Ford engine that needed that cleaned. On the m103 it was an actual potentiometer doohickey.
Hi tnx for your input.
Yep, the MAF on the 104.992 is electronic and was replaced, with a new genuine Bosch about 300 miles ago.
I am not too familiar with acronyms, also most everyone uses slightly different ones.
By IAC do you mean Intake Air Control ( Throttle Actuator )?

If it is the TA, then I replaced mine shortly after I bought the car and I discovered bare wires hanging out from it, shorting everything there was. Aside, it wasn't drivable anyway!
Also, I replaced the e-gas computer (foot compartment, passenger) since it had a damaged input (guess idle contact switch input) and idle was running even higher then now.
The TA has two rheostats mechanically coupled to the air flap. The signal produced, will give the flap position to the ECU ( I believe). One of them is for normal driving and the second one, I believe is used to calculate a delta for the Cruise Control.

It could still be that the TA isn't functioning correctly, since it was a used one, but with good wiring. I only measured top and bottom resistance, before installation. So it could have jumps. I should take a complete resistance curve from it, then I would know.

I should mention that the Crank Case Ventilation is routed through two short rubber hoses and attached to the intake manifold, don't think it is part of the intake at this place. But it routes to the main air intake manifold. The hose connector are some PVC (Plastic intake manifold) and can't handle the temperature changes very well. So it simply cracks and if you look at it, falls off. I needed both to replace, since they were hard as a night stick. The PO did some repairing at the smaller one of the two hoses, but was broken off. So they opted to squeeze a tube of RTV onto it.

I kind of repaired it, using a short piece of brass tube, but has now a much larger inside diameter. I have a hard time to believe that this change would make such a difference in idle. On the other hand, anything after 1980 has become so sensitive and minor changes may have a real big effect.

In any case,
Thank you!
I'll have to check a few more things, cause I can't see why the gas computer would go out of business just by replacing the injectors.
__________________
Mostly, I don't know notin, I just know where to look.
I am looking back, to over 30 years in Electronics Design.
Electrons don't care if they move in a car, computer or relay!

95 W124 E320 M104.992 - Because, I love to repair, naaaah!
Over 221,000 Miles
Cheers,
Norbert

Last edited by oldtrucker; 10-11-2014 at 01:33 PM.
Reply With Quote