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Need help. Car was ruunig poorly and now not starting at all

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    Need help. Car was ruunig poorly and now not starting at all

    Hey guys.

    Looking for some help or suggestions if anyone's got them. I'll start off by saying that im not elctrically savy at all. Besides having a volt meter and measuring the volts and looking for broken fuses I'm clueless.

    Background on the vehicle:
    Its a '85 318 that came with an automatic m10.
    I got a hold of a donor '89 325 with a manual and 173 dme.

    One of my friends, that lives far away now, helped me do the swap and install the new harness and merge it with my original fuse box. After a lot of hard work the the vehicle was up and running. After a couple of months of driving, we got some rain and the car startedd driving funny. It started getting lots of hesitation once up to temperature. It would only stop hesitation once I went to full throttle. A rough Idle also developed as if I had a big camshaft. I stopped driving it and did some looking around. The donor car had a funky custom exhaust past the manifold colectors. The Oxygen sensor was a bit too close to the chassis and there was a dark spot on the frame.

    I found a stock replacement exhaust and installed that with the oxygen censor it came with. It seemed to fix the problem but it was only very temporary. I looked at the fuse box to see if anything was burned. My fuse box cover doesn't say anything so I didn't know what to look for. I found a 15 amp fuse that was burnt ot and replaced it. Again Seemed to fix the problem but again went back to how it was. Heavy hesitation unless full throttle. At some point I seemed to figure out that the battery was being slowly drained and went bad.

    At one point I thought "maybe something in the DME got fried?" so i borrowed one of my friends working DME and the problem was still there.

    I took off the Oxygen sensor to inspect, which I should have done when I replaced the exhaust, and it was covered with build up. I bought a brand new bosch sensor and installed it. Also got aa brand new battery. Seemed to greatly help! Most of the hesitation was gone but still Idleled a little rough. I decided that the next day after I got off work I would adjust the valves, clean the maf sensor and replace the temp sensor. I fugured it can only help since I didnt do those things when I first did the swap. I did those maintanances and then tried to start the car but nothing. Checked the voltage on the battery and it was 12.10 volts. I recharged it but still nothing. not even a click or anything. While still trying to figure out what was happening the only thing I could hear activating was the Idle control valve.I noticed that I dont hear the fuel pump either. The lights on the dash turn on but when i go to start nothing happens.

    I'm kinda stumped. I really dont know what to check at this point.

    Please Help???
    Last edited by Ocard; 04-27-2014, 03:54 PM.

    #2
    A smoke teset and a rail pressure and FPR flow test would be the immediate action items.
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment


      #3
      Sadly I don't have the equipment to do a smoke test and wouldn't I need to get the pump working before I can test for fuel pressure and such? which I also don't have the equipment for.

      also got all the fuses sorted out and looks like all the relays are working (swappedd them out with the horn relay) and still no luck

      Comment


        #4
        Not all of the relays can be swapped with the horn relay. If you turn the key and don't even hear a click, your battery is toast or your ignition switch is bad. You should be able to jump two of the pins in the diagnostic connector, would be 11 and 14 if you had the original harness...not sure what they are for the harness you swapped in. This should activate the starter. Make sure your parking brake is on, and the transmission is in park before you do that! At least you'll narrow the list down somewhat. If it comes on, move to the next steps of checking for spark. If not....try a new battery, or main relay. The ECU looks for several signals before it activates the fuel pump, one or more is missing here. Are your reference and ignition sensors on the transmission nice and tight? You said everything was good until you got rain, there's a clue....

        Comment


          #5
          I currently have a harness, engine and manual transmission that came off a 1989 325i. The battery is brand new and I took it to get tested to make sure it was good since it didn't start the car.

          The rain incident happened like 6 months ago. I got the new battery like 2 weeks ago. From the last start to time it didnt start was a time frame of a day. And in that the the changes I made was adjusting the valves, cleaning the maf and changing the water temp sensor.

          And which is the main relay? I found a diagram that shows relays from K1 through K8 but none of them say main relay. Normal speed, horn, high beam, low beam, unloader relay, high speed, unloader relay and fog light relay. There are 3 other ones that aren't in the fuse box but seem to be clicking when I try and turn on the car

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            #6
            After a long trial and error session today I think I may have made some progress. I tried to jump the starter. The starter didn't react but when I tried to jump it I could hear the fuel pump prime.

            So it seems like the starter is probably out but it seems weird that the fuel pump needs that circuit to complete for the fuel pump to start working. Idk if that is due to the fact that me and my friend could have wired something up wrong or if that is the way the car is set up.

            At least I have something to go off of now.

            If anyone has a picture or a link to a picture of how an e30 starter is wired/set up I would appreciate it. I've only over seen mine and it wasn't assembled when I got it off the donor car.

            Thanks

            Comment


              #7
              There is definitely something messed up here if you heard the fuel pump run when the engine wasn't turning. The pump is controlled by the DME and only runs when the DME sees timing data from a rotating engine. It doesn't prime when the ignition is switched on.
              The car makes it possible, but the driver makes it happen.
              Jim Levie, Huntsville, AL

              Comment


                #8
                It doesn't? I'm fairly certain that even before I did the swap and everything was untampered with the fuel pump would go on for about 3 second or so while on the on position and would go off if you didn't start the car.

                I may be mis remembering... that's always a possibility lol

                I did some digging in my laptop last night and found my copy of the Bentley manual and it has a troubleshooting section that's pretty simple to follow. I'll go through it propperly instead of me just randomly poking around with my voltmeter and report back.

                I really appreciate any and all comments! Thanks

                Comment


                  #9
                  Originally posted by Ocard View Post
                  It doesn't? I'm fairly certain that even before I did the swap and everything was untampered with the fuel pump would go on for about 3 second or so while on the on position and would go off if you didn't start the car.
                  As far as I know the prime function was never implemented in any M20 DME.
                  The car makes it possible, but the driver makes it happen.
                  Jim Levie, Huntsville, AL

                  Comment


                    #10
                    While I was at work I was thinking of other things I could test or do. I decided that I would double check the grounds. The one from the oil pan to the chassis was a bit dirty so i decided to use my spare jumper cables as a grounding kit.

                    AAAAAAND MY CAR STARTS!

                    starter struggled but started. I let it warm up and noticed the idle was fixed. tested the voltage at the battery and notice an increase from 13.02 to 13.55volts. Decided to take it for a dride and the hessitation is GONE!!

                    I drove it back into the garage and it seems like the starter is legitametly out but the car ran and ran well. I'm a happy guy.

                    Comment


                      #11
                      Hey guys just here to provide an update:

                      The car is now running great! I did need a starter but the extra grounds got rid of the bad idle and the terrible hesitation.

                      So lesson of the story is: You can never have too many grounds :D

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