Hi guys, need your help again. As you remember, i chaged the fuel pump some days ago, but the car dont want run well.... When i put the key in position III, the fuel pump runs well, i can hear it. When i put the key in start position, the engine starts and run....but only for a few seconds.... Again, key in third position, fuel pump is ok, start position, the engine start...and run only few seconds.... i clean the fuse box, all the contact are in good condition, put new relays, and put fuel (of course). I dont know what is the next step, any thougts ? Thanks in advance
So many possibilities. Are you sure the new fuel pump is working correctly? The only way to tell is to do a full CIS fuel pressure test. You need a CIS test kit for that.
The fuel pump should not run unless the engine is running or the key is in the start position. If your fuel pump is running before you turn the key to the Start position you probably have a problem with the Safety switch. That is not a solution for your current problem, it is ANOTHER problem. My car had the Safety switch problem when I purchased it and I did not realize it was a problem. In my case it was just corroded contacts at the safety switch. All I had to do was disconnect it and reconnect it a couple times and it started working correctly. The connection comes apart easily no hidden clasp or snap just pull. See this thread for more details. I guess they call it a "Safety switch" for a reason so probably a good idea to have it function correctly. I think it is one of those worst case scenario things like the "Roll over valve". The roll over valve prevents fuel from coming out via the charcoal filter if your car is upside down. If you engine stops running for any reason say an accident or a broken fuel line The safety switch should shut off the fuel pump even though the key is still in the run position.
Your problem is one that "fits" with how the electrical system for the 328 fuel pump is designed -- power to close the fuel pump relay (and run the fuel pump) comes from two different paths for the Pos II (run) and Pos III (start) key positions -- so it's possible that Pos III works (and runs the fuel pump for a few seconds during starter motor cranking), but Pos II doesn't (and the engine dies after a few seconds when the fuel pressure decreases). Did you replace both the ...113 relay R ("relay for fuel pump") and the ...101 relay S ("Fuel injection delivery pump starting-relay")? If you would like to test that the engine is running OK, remove the relay R and connect a jumper wire from the 30 terminal in the female relay socket to the bottommost 87 female terminal in the relay socket as shown in this jpeg. This will run the fuel pump all of the time (even with key "off") -- so connect the jumper, confirm (audibly) that the fuel pump is running, start the engine, and confirm it will now run more than a few seconds. Image Unavailable, Please Login
first of all, need to say thanks a lot for your response. Too much information, and need to work hard in the next days to resolve the problem. I think the fuel pump was fitted correctly, is easy to comprobe. Referring the Safety Switch, i unpluget it and then, i cannot hear the fuel pump, but the engine runs...(only a few seconds). Relays affair, i put new 113 and 101 but not exactly the same model, there are aftermarket, not Bosch. The guy in the store tell me that this relays are the same with different item number... I have to work in all you told me in your response, and will be in contact after that. Thanks again
On my 85 308 I can see it when I remove the right side rear wheel well liner. Image Unavailable, Please Login
I was temporary out of my place and didnt work til now. Well, i did it (connect a jumper wire between the 30 terminal and the bottonmost 87)......and the engine runs ok. Then, what is the problem ? the relay is new, is not exactly the same but i dont think the problem is.... Steve, could you help me in this mistake ?
Your substitute relay for relay r is probably OK if it has the same terminals -- 30, 85, 86, and 87. Do your turn signals work with the key "on"? Also, (with all the relays plugged in) if you unplug the safety switch at the airflow meter, and turn the key "on", does the fuel pump run? Image Unavailable, Please Login
If i unplug the safety switch, the engine run a few seconds, but the fuel pump doesnt run, and whit the key "on", all is silence, there is no fuel pump.
Well...the car is in the way to go to the paint shop, and then, most of the plugs are unplugged. Only the plugs concerning the oil pressure and some dashboard ligths are plugged in. Yes i have a voltmeter.
Understood (and would explain why, if your turn signals are not working, that you hadn't noticed ) -- my reference for this discussion is the 376/86 OM (early euro 328) so let me know if your car doesn't match in some regard). 1. Try a different ...113 relay (or equivalent) in the relay U (relay for key controlled services) position. By touching the outer case, confirm that this relay U "clicks" when you turn the key "on" -- redo the "unplug the safety switch and turn the key 'on' to run fuel pump test" (I'm going to call this the "USSTKO test" for short) and see if the fuel pump runs or not. If not (but the different/new relay U works OK), 2. Unplug and reseat all the connectors on the fuse-relay panel. Jumping the fuel pump relay socket and having the fuel pump run OK says most of the wiring and connections are OK, but there is still one ground connection involved in controlling the fuel pump relay R that passes thru one of the connectors. Repeat the USSTKO test, if still bad, 3. Remove ...101 relay S (fuel injection delivery pump starting relay) and only partially plug it back into the socket so that all of the male tabs are making good electrical connection but are exposed enough that you can touch them with the voltmeter probes. With the safety switch unplugged and the key "on", measure the voltage between terminal 30 and ground -- should be +12V, if it is 4. (Fully reseat relay S) Remove ...113 relay R (fuel pump relay) and again only partially plug it back into the socket so that the male tabs are making good electrical connection but are exposed enough that you can touch them with the voltmeter probes. With the safety switch unplugged and the key "on", measure the voltage between terminal 85 and terminal 86 -- should be +12V, if it is, your car should be working so let us know where you drop out of this test sequence .
Steve thans a lot for your time and for your help.... I have to say at first, that the relay "u" never works well, this relay always sounds like a "buzzzz", when i put the key on. When i yesterday put the jumper wire in the relay "r" and the engine runs good,when the engine runs, the "buzzzz" stopped. If i change this relay, the "buzzz" changes, but still working bad because when i touch the relay, i can feel the "buzzz" in my finger, then i understand the relay "u" doesnt work well......or is the relay socket? Other thing i didnt told you, is that i disconnet the wires two weeks ago in the main key and dont know really (i have serious doubts) if i plugged the wires in the correct position.....
Well you definitely need relay U to be working well because this is what supplies the +12V power to actuate relays R & S. Just like jumping the relay R socket from terminal 30 to terminal 87 to simulate a properly closed relay R, you can try removing relay U and put a jumper wire from terminal 30 to terminal 87 to simulate a properly closed relay U. If jumping the relay U socket (with the R & S relays plugged in) solves the trouble (i.e., you pass the USSTKO test with the U relay socket jumper in place) you've found the root of the trouble. Since you tried more than one ...113 relay in the U position, and they both buzzed, the trouble probably is with the socket or the upstream wiring. The +12V power from the key switch and the ground signal to close relay U both pass thru connectors on the fuse-relay panel so unplugging and reseating the connectors may help. As far as the wire connections at the key switch: -- the two R (red) wires are always +12V and should be connected to terminal 30 -- the GN (yellow/black) wire should be connected to terminal 15 and should be +12V when the key is "on". This is the wire that eventually goes to the relay U socket and is what causes relay U to close when you turn the key "on" and it goes +12V. (the ground signal to the other side of the U relay coil is always supposed to be present). -- the B (white) wire is the start command wire and should be connected to terminal 50 and would be +12V only when the key is in Pos III (start). Bottom line is that you need relay U working properly, and well, before worrying about relays R & S and the fuel pump running or not. Advise what you find and we'll go from there.
Hi friends, back again from a short holidays. Testing the relais i have found some news, the most important is what i found testing the "r" relay. Checking the current between the terminal 30 and the terminal 86, i have 12 volts with the key off......but its turn to 7 volts when i put the key in II (on ) position, and III (start) position. The most interesting is (pluggin in) the relay "r", if i put a wire directly from the 86 connector (ground) to the chassis (ground as well).....surprise!!!! the car runs perfectly, the fuel pump run only when the key is in start position, and all is ok. I suposse i found the trouble but, what is the next step to resolve definitely the affair? Looking desperately for your response..... Thanks
You don't need it -- if you: 1) know that terminal 86 on relay r, when plugged in, is supposed to be a good ground, and it isn't (i.e., measuring the voltage between 30 and 86, with relay r plugged in, and getting something way less than 12V), and 2) when you connect a jumper wire from terminal 86 to a good ground and the voltage between 30 and 86 now measures OK (and the car runs fine), I think you can be pretty sure that you need to either make a repair, or add a more permanent jumper, so that terminal 86 is always well grounded (but I didn't check the schematic). Does relay u also behave better with the jumper in place?
Thanks Steve, all is correct with the jumper wire to ground, but what is wrong ? is there a crash wire? is there a crash socket in the fuse box?. The "u" relay dont "buzzzzz" anymore with the jumper to ground in the "r" relay. I think we are in the end of the trouble, but what´s wrong?. Of couse i could put an "extra" ground wire on terminal 86 but, is this the correct way to resolve the problem?
It could be depending on just what the trouble is and how deep that you're willing to go to fix it. Here's the schematic (from the US 328 wiring diagram which should be the same for all 328 versions for this area) showing that relay u and relay r do share a common ground connection to their 86 terminals that passes thru connector V. First thing to do would be to check the condition of the connection at the V connector. The other possibilites are a broken trace on one of the PCB layers or a bad connection for the wire on the other side of connector V which should be hooked directly to the metal chassis (ground). Image Unavailable, Please Login
