Montonic question - help needed PLEASE, 1987 E30
Hello All !
Just joined because I found similar threads searching for info - some of you are very sharp and I would appriciate your help big time.
I just bought a 1987 325IS as a project restoration and had it shipped to me . It was running but blew a freeze plug - perfect b/c I can fix easy and got it for great price. I planned on instant rebuild anyway.
It was running when they loaded it on the trailer. The car had blown a freeze plug so they ran it just a min to get on truck. when It reached my home I just pushed it in garage and began the tear-down.
I went to town on it, 2500+ dollars in new everything - after doing a complete timing belt job, tune up, valve adjustment -total freshen up of engine minus pulling head and pistons (next month).....
I tried to start it. I wouldn't start - no fuel pressure. Went through my Bentley book did tests and fuel pumps run with jumper. Voltage is coming to relay -so I changed out the fuel pump relay and main relay. Still did not start - bench tested relays and they click and close circuit fine. but when you stick relay in car socket, with voltage present - no click, no fuel pump.
What I found is that the 12 volt side of fuel pump relay has + power signal to close - BUT the ground brown negative side is not there, ungrounded - no continuity to ground. If you have the relay in place and jump the ground wire to chasis from under the socket - relay and pumps operate. (socket is good)
That leads me to the Montronic ECU - that brown wire ground goes to it. Also the relay next to it (lights)and the main I believe do not have ground connection. (however lights will work)
I followed ground troubleshooting on Montronic with Bentley manual - some of the ground continuity checks came up bad (open). I looked at all the ground connection points on the car - everything looks good - leaving me to ask is it the Montronic unit that is bad ? Does it use those ground wires to signal the various functions ?
Even with the fuel pump running by jumper wire - the car doesn't start leaving me to believe the injectors are not being told to fire either. Some interior functions are not working although fuses are good, like power windows and some lights, little computer read out, etc - some functions work fine and car will turn over all day. (later today I will check for spark but don't think its there)
Another thing funny is with ignition off, I read continuity to ground from several of the fuses in fuse box - all that should be isolated 12+, making me think there is a ground somewhere.
Would the montronic going bad / being fried cause all this confusion ?
There were also indications that the cars battery could have been put in backwards at one point, the large wire from alternator to starter + was burned. I replaced it and closely inspected and repaired any damage to wires touching that burnt one. Would that fry the montronic ?
All fuses are good, changed out, fuse link good, relays all new - and this no ground in montronic wires seems to be keeping car from starting / running.
Help please ???? Any ideas ??
I have this beautiful E30 sitting in garagefreshly tuned with new 17" Beyern mesh wheels, new brake kits, coil-overs, all new grill, fresh painted engine - shes just beautiful and ready to go......but wont start and I'm pounding my head at this point !
Thanks so much for your time - I'm stuck
PS - to make things more confusing, when reading Bentley manual I noticed I had the Montronic 1.1 updated version ECU with (50)? pins - but the plug has less pin connections and wire harness looks like there are possibly professional factory like splices....this model year 325 is right around the date they were swapping to the 1.1 version - did I end up with a hybrid assembled car / wire harness adapted to run on newer Montronic 1.1 ?????? aaagghhhhh
Thanks !!!! Garet