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E28 (1982 - 1988)

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  #26  
Old 08-25-2011, 08:16 AM
Ataglance Ataglance is offline
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Thanks Tecmec. It turns out I have no spark when inserting a copper wire into plug wires while turning the engine. I removed enough to check the timing belt and it feels firm so I think that is okay. I tested the ignition coil the way Chilton says and it passed those tests.
There is no spark in the wire from the ignition to the distributor, though.

It does seem the distributor is not connected to the ECU from the Chilton diagram.

I have a new ECU on order and if it is good I am going to post the contact information on the seller who specializes in used German car parts (after calling 20+ junkyards in Michigan none had any 528e in the yard but one of them recommended this seller.)

I posted also about fuse 1. Should there be continuity on both sides of the fuse holder? Fuse has been changed a couple of times like the Fuel Pump Relay has been.

I am baffled that there is voltage from the ECU to Fuel Pump Relay and I can start the jumper wires by connecting the red to the green/violet in the relay.

I even tried to start the car with the pumps jumped like this and no luck.

This is such a great car I don't want to give it up. Engine is great and it looks great.
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  #27  
Old 08-25-2011, 02:18 PM
Tecmec Tecmec is offline
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I am not surprised by the no spark. I was thinking earlier that the fuel pump if not the real issue was the lessor of evils at best, when you did not get any sputter when you used starter fluid. While you are waiting for the ECU I would read out the plug wires and satisfy myself that the plugs are good. Also, you could check the distributor cap and rotor. Finally you should read out the pulse and reference sensor (although I believe you only have one, earlier models had a reference sensor as well as the pulse). Forget the timing belt, and I believe it is a chain on your vehicle. If the distributor shaft turns all is well in that area. The chain would have to be worn pretty good to jump a link or the like. If the tensioner went enough to let it jump you would know it big time. If it did jump the vehicle would most likely start or try to start but would backfire or misfire. I think you are getting pretty close to the ECU ending your problems. Most times a no spark if not one of the items I cite above, is the result of a bad ECU.
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  #28  
Old 08-25-2011, 04:06 PM
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catso catso is offline
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Quote:
Originally Posted by Tecmec View Post
I am not surprised by the no spark. I was thinking earlier that the fuel pump if not the real issue was the lessor of evils at best, when you did not get any sputter when you used starter fluid. While you are waiting for the ECU I would read out the plug wires and satisfy myself that the plugs are good. Also, you could check the distributor cap and rotor. Finally you should read out the pulse and reference sensor (although I believe you only have one, earlier models had a reference sensor as well as the pulse). Forget the timing belt, and I believe it is a chain on your vehicle. If the distributor shaft turns all is well in that area. The chain would have to be worn pretty good to jump a link or the like. If the tensioner went enough to let it jump you would know it big time. If it did jump the vehicle would most likely start or try to start but would backfire or misfire. I think you are getting pretty close to the ECU ending your problems. Most times a no spark if not one of the items I cite above, is the result of a bad ECU.
528e has a timing belt.
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  #29  
Old 08-26-2011, 08:48 AM
Tecmec Tecmec is offline
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Thanks for the correction. I know the 533i and 535i have the chain. I assumed the 528 did as well and you know how that goes. 50/50 chance and I was wrong. That is why I do not gamble. Have a good day and take care if you are located in Irene's path.
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  #30  
Old 08-27-2011, 07:06 PM
wavell5er wavell5er is offline
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bmw 5351s

i have an e28 535is stick. am having the same problem with no current to the fuel pump.i have change everything in past 5 yers which is a problem on these cars.one thing for sure is the cpu is not putting out the ground to the relay for the pump.i have try 5 cpu and one did some thing wrong.turn the pump on like crazy.which tells me that the harness might be comming losse inside?did enyone have this problem
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  #31  
Old 08-30-2011, 08:42 AM
Ataglance Ataglance is offline
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Hi,

My ECU is due to be delivered today. IF it is good I can post the name and number of the place I brought it from and that would help our online community.

But I was wondering if you can bench test the ECU by jumping it to I think 19 and grounding it?

The ECU was making a humming sound earlier but now it is not.

I am afraid to check the spark because I think my starter is on the way out. I had to give it a hammer stroke to make it run.

I have no spark otherwise. I know the ignition coil is good and voltage is at the ignition wire and probably the timing belt is correct. I cleaned the distributor but still afraid to burn that starter.

Maybe I can test the ECU with a 9volt? Thank you and thank you again.
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  #32  
Old 08-30-2011, 04:40 PM
Ataglance Ataglance is offline
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New ECU (used) and the problem continues. There is spark. The starter is going I had to hit it with a hammer.

Does the ECU actually turn the pumps on prior to cranking at stage 1 to get the fuel pressure up? I have not heard them do that and that it done on other cars.

Any help is appreciated, I am about at my wits end.
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  #33  
Old 08-30-2011, 04:43 PM
Ataglance Ataglance is offline
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How do you get it to put out the proper ground?
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  #34  
Old 09-04-2011, 09:41 AM
Ataglance Ataglance is offline
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Hello everyone again,

It looks like my beautiful 528e is still down for labor day weekend.

But does anyone know what the voltage should be at the green wire of the main relay (the one from the ECU). There is continuity b/n the ECU and main relay but there is only 1 volt at the main relay with the ignition on.

Also if I run the wire from the brown green wire (from ECU to fuel pump relay) on the fuel pump relay to the green violet it runs the pumps but the car still does not start.

Seems the connection from main relay to fuel pump relay is good. The relays have been changed with ones from the dealer.

Happy Labor Day.
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  #35  
Old 09-04-2011, 05:38 PM
Tecmec Tecmec is offline
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To recap, I believe we are back to having spark but no fuel delivery. Is that the case. I am beginning to feel I am hindering you more than helping you. I know I have myself confused at this point. Reading over the previous posts it seems you are loosing ground. On 8/16 there was voltage when cpu 36 was grounded and you heard the relay click. Likewise on 8/18 and 8/22 seemed like most of the checks were as expected. I believe you need to look for a bad ground or a broken wire in the circuit.The principal grounds are G102 (on fender behind LH headlight) and G103 (above starter on engine block, could be front of engine under diagnostic connector). Others are G200 (under LH side of dash, near brake pedal), G301 (under LH side of rear seat) and G302 (right side of trunk). There could also be one from the right valve cover to the fire wall, and/or one at the rear inside end of the block in the area of the fuel rack, and one from the frame to the motor mount on one side or the other (found from underneith). Also, you asked about the voltage at the main relay from ecu pin 36. Pin 36 does not send any voltage to the relay. The voltage comes directly from the battery to pin 86 of the relay. The green wire going from the relay pin 85 to the ecu pin 36 is put to ground through the ecu and that give the path back to the negative side of the system and as a result the relay is activated (the click you heard). When so activated power now flows from the battery through the fuel pump to ecu pin 3 which would be put to ground. If this happens, the pumps are powered. Again, I would clean all grounds, especially G102, 103, and G301. Then I would try to read out the green wire and some of the other primary wires in the system while I bend and twist the cables a little. Think back, did you extensively move or flex any cables before everything went south. Now that you have spark, does the vehicle fire when starter fluid is sprayed into the intake? If so, again I would look for a bad wire. Be sure to check the red wires from the battery to the main and fuel pump relay. If you are satisfied they are good, go on to the wires in the main harness going from the relays to the ecu and the wires from the pump relay to the pumps. You may need a helper to watch the meter while you exercise the wire. Good luck and sorry I can not be more help. Perserverance will pay off in the end.
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  #36  
Old 09-07-2011, 04:58 AM
Ataglance Ataglance is offline
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Hi Tecmec,

You have been a lot of help, thanks. This is my first time dealing with this type of electrical thing.

I am going to check those grounds you mentioned. When grounding the ECU wire that connects to the fuel pump relay the pumps run.

But the pumps don't stop and shouldn't they stop if the engine isn't cranked? The engine still doesn't start even with the pumps running. I wonder if a key to the problem is that the pumps are not energized when ignition is on and not stopped when engine is not cranked.

Is it some type of sensor causing the ECU to not turn off the pumps, so maybe the ground is bad and a sensor?

I don't know if this relates but before the fuel delivery problem I had the differential mount break that had to be replaced. The car started this current problem after I replaced that.

Gear selector switch on the differential is bad? Continuity is on that circuit. Don't know.

Still don't want to give it up but I got another car while I work on this. But I miss the bimmer.
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  #37  
Old 09-07-2011, 05:47 PM
Tecmec Tecmec is offline
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Have to think about the differential mount more, but I would not see that as related. I would have to know more of what they did and exactly what mount you are talking about. You state that you ground the wire from the ecu to the pump relay (I assume we are talking about pin 3) and then state that the pumps run but do not stop and ask should they if the car is not cranking. No, with pin 3 gounded and pin 36 grounded the pumps should run regardless of the engine not cranking. Having two ecu and no better luck I would not point at the ecu for the moment. Perhaps it is time to review notes, review what has been tried and go back to some basics. To start the engine all we should need is a good battery (cranks engine good), fuel, properly timed spark, and sufficient compression. The ecu and the different sensors provide inputs but most of their purpose is engine control, driveability, emissions, and efficeincy. I.E. with out most of them the car should still strart but may run terrible. The things to check would be the main relay (check this simply by turning on the ignition, you should clearly hear the relay click). Then the Test and Reference sensor. You have a combined sensor on your vehicle. It is located at the front of the engine at the vibration damper. The connector is by the diagnostic connector under the hood. It should be the one closest to the dip stick. I do not know if it is gray or black in color. To check this sensor you can read the resistance, on the sensor side of the connector, between pin 1 (yellow wire) and pin 2 (black wire). Resistance should be about 540 ohms +/-50. The sensor should be spaced from the toothed wheel about 0.40" +/-0.10". Because of the location and the robustness of the sensor I would not expect the sensor proper to be damaged. But it could be electrically bad. Ohms out of range replace it. Next would be the spark followed by fuel. Another check for fuel is to remove the fuel line at the fuel rack, hold it over a container and run the pumps either by jumping the relay or better, turn the key to start. When the key is in start the pumps should run. A couple of things we haven't talked about would be the air flow sensor and the temp sensors. I would put these low on the list. These are checked for resistance and if in proper range are deemed good. We can cover those later if needed. Right now I would reverify the main relay, the fuel delivery, the spark, and the test/reference sensor, in the order I cited above. Again, I would also verify I have good grounds as discussed earlier and make sure I do not have a bad wire in or at a connector or in a harness. I.E. read out the cables while exercising the harness and cable runs. These vehicles are known to have wiring issues. Good luck, stay safe, and think about what you are doing.
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  #38  
Old 09-08-2011, 12:59 PM
Ataglance Ataglance is offline
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I will do that. My sons and I are going on our annual canoe trip this weekend (taking a well-deserved BMW break). But I am going to persist and save this vehicle from the junk yard. and I think it is worth it.

Regarding the ECU, it is not pin 3 but the other end of the wire at the fuel pump relay that I put to ground and the pumps like wise ran with the ECU in. That is interesting that it would be more poor running and not no start if it were the ECU.

Actually, the ground from the neg. post on the battery to the frame I found broken straight through about two weeks ago. I replaced it but that did not change anything but I also saw what I think is the ground wire from the alternator or voltage regulator broken straight through (this is before I even started checking the grounds I noticed this.) It is like something is chewing them.

I am going to check those grounds and those sensors. There must be an answer somewhere. Thanks and thanks again.
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  #39  
Old 09-16-2011, 11:19 PM
wavell5er wavell5er is offline
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no start

hi all am still having the same issue but every so often the car will run fine and stop.both fuel pumps went due to jumping a wire from the relay to the pump,the only problem is the fuel filter was clugg .so i thank i might burnt a wire some were in the harness or ground. i only have the weekent to work on the car.will keep u posted on what i come up with. 88 535is stk
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  #40  
Old 09-17-2011, 06:39 PM
Ataglance Ataglance is offline
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Yes please let me know what you find out. As for me I have starter to replace or repair now as engine will no longer even crank.

I found a disconnected ground that runs to ground by but not related to the alternator today.

Trying to see if I can take the intake manifold off. It is easier to get to the starter.
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  #41  
Old 09-18-2011, 05:12 AM
Ataglance Ataglance is offline
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Also I don't think it harms the pumps to jump them so long as there is fuel, so are you sure the pumps are bad?

Also do they run for a few seconds when you put the key in? Mind don't unless they are jumped or some wire is put to ground and then they run.
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  #42  
Old 10-22-2011, 10:23 PM
bigmikes84bmw bigmikes84bmw is offline
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no start

im having same problem but my 528e will start with starting fluid ived changed ecm both relays and refrence sensor but not speed sensor ran most test you stated i dont have power at the external pump please help me
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  #43  
Old 10-23-2011, 05:44 PM
Ataglance Ataglance is offline
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Do you have power at the other pump? If so is the external pump bad?

If you can jump the external pump maybe the connection is bad b/n the two pumps.
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  #44  
Old 10-23-2011, 10:21 PM
bigmikes84bmw bigmikes84bmw is offline
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havnt tried that but im not getting power at fuel pump fuse at all will try jumping external pump but really think its wiring short with no power to #1 fuse fuel pump fuse what do you think
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  #45  
Old 10-24-2011, 06:53 PM
Ataglance Ataglance is offline
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Are you able to jump the fuel pump relay and hear both pumps spin? If so it is maybe a short before the relay.

This would mean it is likely a short before the fuse from what you are saying.

Although my deficient diagrams I purchased don't have the fuel pump fuse it should be before the relay.

Basically the thing is to isolate the wire where the short is and change that wire.

Make sense?
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  #46  
Old 10-24-2011, 07:23 PM
bigmikes84bmw bigmikes84bmw is offline
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hey guys i have an 84 528e im having same problem no power to fuse at #1 for fuel pump ive already replaced new refrence sensor relays and ecm please help im going crazy
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  #47  
Old 10-24-2011, 07:26 PM
bigmikes84bmw bigmikes84bmw is offline
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yes atag makes sense but i checked as much as i can to no avail im going crazy
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  #48  
Old 10-24-2011, 07:28 PM
bigmikes84bmw bigmikes84bmw is offline
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and car will start with starting fliud then die
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  #49  
Old 11-03-2011, 07:05 PM
mikesalot34 mikesalot34 is offline
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I'm having the same problem. It's in the car alarm. This was told to me by a mechanic today. He was actually nice enough to lend me a ecm to see if it was that part. I've been going nuts too!! Lol

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  #50  
Old 11-03-2011, 07:10 PM
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catso catso is offline
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Originally Posted by mikesalot34 View Post
I'm having the same problem. It's in the car alarm. This was told to me by a mechanic today. He was actually nice enough to lend me a ecm to see if it was that part. I've been going nuts too!! Lol

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Factory car alarm or add-on?
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