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Old 07-04-2012, 08:33 PM
redhead redhead is offline
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Location: indiana
 
Join Date: Mar 2012
Posts: 2
Mein Auto: 1999 325
e23 Euro car, 723 power help.....

Bimmerfest gang, fisrt, you guys and gals rule, i have had quite a few problems solved by reading the forums, and listening to what you have to say, but, i have a new adventure that i don't see anywhere on here, so hopefully the vast knowledge of the bimmerfest crew can help:

The backstory, this is a 1981 732i, "grey market" brought over from sweden by my wife's god father, he no longer lives here, or drives it, hasn't drove it for about 11 years, sitting in his garage, until he thought it would be a good idea to my father-in-law and i have it, to "get it going" again...... as you know, the 723 was never sold here, the motor never sold/serviced here, and the little documentation i have been able to get from germany is not a lot of help, as this motor didn't last very long in the BMW world. So, here goes:


1981 BMW 732i (e23)
Attempted revival after sitting in garage for 11 years.
Condition: About 140,000 miles on odometer. Starts and runs OK after installation of new Bosch fuel pump and filter. Engine responds to throttle when not under load (out of gear). However, it will not accelerate when driven. It appears that there is fuel starvation when the throttle is applied under load.
Checked fuel pressure at the rail--~28psi at idle. When driving pressure drops to under 10psi when throttle is applied and vacuum drops to near zero inches. Checked fuel pump by brief (very) crimp of hose and pressure rose to 70+psi. So pump seems OK.
Installed new fuel pressure regulator since pressure was somewhat low during initial test and some sludge was removed while being cleaned with carb cleaner.
Same reaction as with the original regulatoróran fine in the garage but would not accelerate on the road and had the same pressure drop with throttle application.
Am I wrong in my belief that reduced vacuum should cause the regulator to increase in pressure in order to increase fuel flow thus causing acceleration? Why the pressure drop?

Please, any good ideas as to why the power just dies will help. We are not going to sink thousands into this car, but want ideas as to why this might be happening, just to have a fun car to play around with and maybe restore fully.

i hope you can help,
david
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