Author Topic: fuel pump/non-start issues - been doing lots of research, still NEED HELP... please > (Read 44137 times)

RED IS 91 · « **Reply #75 on:** July 23, 2008, 05:58:54 PM »

If you remove the icv you can connect 12 volts to it and see if the little door inside moves when you connect the power.
It's not a good sign to be blowing fuses for the fuel pump .It should be a 15 amp fuse for that I believe.

I don't know how that relates to the icv??

also are you sure you hooked the hoses up correctly at the fuel pump??

Colo318IS · « **Reply #76 on:** July 24, 2008, 06:09:33 PM »

...well damn, thought this day would never come, but am happy to say I'm back in business! Just got back from a drive.

I did clean out the ICV, but it was functional and I don't think that was the issue...I started thinking that due to research I had read on rough idles/etc.

OK, I believe the issue was the connection on the pump (thank you to RedIS91 & Cobra Jet)...I did pull the cover off the pump and checked the connection, it was indeed not tight. It fired right up after that and idled normally. I have taken it out a few times and so far so good.

Thanks so much for everyone's help!

Jay

Cobra Jet · « **Reply #77 on:** July 25, 2008, 12:04:51 PM »

Wooohoooo!!

Glad to hear it's running again Jay and that this thread helped you out with your non-start issues.

So, in the end, it was the actual plug that goes on the fuel pump? Was it corroded or just loose?

What I also did w/ my fuel pump plug was I had opened the hard plastic that surrounds the inner metal female connectors (it's easy to do, just use a small flat head screw driver and pry the two plastic pieces apart carefully). Once I had the metal female connectors in my hand, I used a pair of plyers and pinched each one ever so slightly. What this did was to close up each round opening on each connector just a little so that when reinstalling the main plug back onto the fuel pump connection, it would now "grip" and be more secure on the fuel pump than it was previously. You may want to consider doing that if yours was loose. Also, just remember which connector goes back into the plug when putting the plug back together - because if you reverse polarity, the pump won't pump fuel out of the tank... LOL (learned that from experience)...

Great to hear that you're now out & about! Best of luck!

RED IS 91 · « **Reply #78 on:** July 25, 2008, 01:27:43 PM »

another happy ending, that's what we like to hear !:D
congratulations

Colo318IS · « **Reply #79 on:** July 25, 2008, 06:42:32 PM »

yes, mine was just loose, nor corroted, thanks for the tip, I will do that.

I dunno, it was a little bit of a blur when we put the new pump in and I honestly thought it was tight, but evidently not. Well one side benefit...prior to this issue, when I would start it, it would have a hard time maintaining idle until you drove it a mile or so...now after cleaning out the ICV..WOW, what a difference...idles like a champ.

Yes, very excited to be drivin it again! Thanks again...i hope one day to return the favor!

Jay

rt325 · « **Reply #80 on:** February 11, 2009, 07:14:48 AM »

Having a very similar issue, looking for some additional guidance.
I believe these could all 3 be related but not sure.
My fuel pump relay is having issues.
Has no ground, when I make a set of jumper wires I can make it work, yet when plugged in the Ground is lost. Is the ground routed to the computer (book states this) or elsewhere? I have an extra computer, tried it with no change in result so believe the ground must be else where.
Pump is only getting power when the key is in the START position, no initial2 sec power up and once key is to on position nothing, possibly due to the non start I am sure. But it should have the2 sec power up and it does not. What controls this, computer?
Last issue which may be the root of all this evil is (quite working on it when I found this) the Cam position sensor appears to be dead we cannot get it to read any ohms�, nothing tried all the combinations. What could this effect, all the above? Where is the best place to get a new one dealer or does someone else have them at a better price? BMA?
Thank you in advance.
Richard
Houston
A few e30's

RED IS 91 · « **Reply #81 on:** February 11, 2009, 05:57:55 PM »

Camshaft position sensor should have 1250 +- ohms . If you don't have that then replace it and report back. Link below to sensor.
Check you crank position sensor also.

http://www.autohausaz.com/search/product.aspx?sid=ovw5r355z2n4ig550yoybp45&makeid=800003@BMW&modelid=1011249@318I&year=1991&cid=25@Ignition%20Parts&gid=7192@Camshaft%20Position/Reference%20Mark%20%20Sensor

rt325 · « **Reply #82 on:** February 12, 2009, 06:09:46 AM »

Crank sensor was okay, in the car, so I did not remove it. Cam sensor has been ordered. I will keep you informed, appreciate it.

Thanks RT

B318M42W · « **Reply #83 on:** February 12, 2009, 10:57:16 AM »

good luck!

lindol · « **Reply #84 on:** April 28, 2009, 10:22:58 AM »

Hi everyone, I am finding this thread very useful in my quest to get my car started again. Last Friday, like the other stories in this thread I went to town without a problem, but when a few hours had passed and it was time to leave I cranked and cranked and cranked some more and in the end had to tow the car home as it just would not fire up.
I have been using the information below to guide me, but I am getting some results that I need help interpreting, I hope the author or others can help! I'll put my comments/questions below in bold and some bright color so you can all see where I am having problems.

Quote from: ak96ss;47710

I concur, it may very well be the crank position sensor, but to confirm that you are in fact getting power to the pump, let's go over how the start circuit works for the fuel pump (as I understand it, anyway!).

Power comes from the junction block down the yellow line to the DME all the time, but the DME doesn't send it into the starting circuit until it senses that you have the key on. So, the blue, green, and red lines have power, but aren't doing anything with it yet.
I have verified that I have power to pin 26 of the DME(Yellow), and I've also verified that there is power at pin 86 and 30 of the MAIN relay as well as pin 30 of the FUEL relay. This is before turning on the key!

When you turn the key to the ON position, it grounds the green line at port 27 (Main Relay Control), causing the green line to have power all the way through the main relay via tabs 85 and 86.
Here's where the problem occurs for me, I can feel the MAIN relay switch close and power goes from pin 30 to 87, but I cannot see power at pin 85 of the MAIN relay???

This energizes the coil and pulls the relay closed, sending power through the main relay from tab 30 to tab 87, and from there to (among other places) the fuel pump relay's tab 86. But the fuel pump relay's tab 85 is still not grounded, so power doesn't go through yet.

The DME checks to make sure that the engine is rotating using the crank position sensor - when it sees that the engine is in fact moving, it grounds the fuel pump relay control at port 1, completing the blue circuit.

I have checked both the Crank position sensor and the cam position sensor, they read 550 and 1200 with my multimeter. I also have removed a spark plug, connected it to the wire and witnessed it sparking while the engine was being cranked. I understand that to confirm the CPS is working correctly, or?

Now that the blue circuit has power going through it, the fuel pump relay coil pulls in, energizing the red line and sending power through tabs 30 and 87 to fuse 11.

Assuming fuse 11 is good, power goes to the fuel pump, and it starts pumping fuel.

If the crank position sensor is malfunctioning, the DME won't know that the engine is turning, so it won't turn on the fuel pump.

So, to systematically test and make sure that the circuits are working as they should, start with a fused jumper wire at the fuel pump relay. I actually use a switched, fused jumper, so I can turn it on and off from the engine area. For all of these tests, when I say 'ignition on' I mean in the RUN position, not the ACCESSORY position.

First, exchange fuse 11 with another fuse (same or lower amp rating, never higher). Just in case the fuse is bad, but still looks OK. It's rare, but it does happen. See if it will start. If not...

Remove the fuel pump relay. Insert one end of your jumper wire into the hole where tab 30 goes, and the other end into the hole where tab 87 goes. With the ignition on, the pump should start pumping. If it does not, but your fuel pump works when hooked directly to +12V, then you have a problem in the wiring between the fuel pump relay and the fuel pump.

My pump does NOT start pumping, is this related to my earlier question regarding pin 85 of the MAIN relay?

If that works, but it doesn't when the relay is in, you may have a bad relay. You can test the relay by applying +12V to tab 86 and grounding tab 85. Now check continuity between tabs 30 and 87 - there should be virtually no resistance. If there is a lot of resistance, or there is no continuity, replace the relay.

If the relay works, it may very well be the crank position sensor. Get out your multimeter and check the hole where tab 86 of the fuel pump relay goes. With the key on, there should be +12V there. If there is, then I would strongly suspect the crank position sensor.

If there isn't, you'll have to do the same tests on the main relay.

Looking forward to any help I can get, I have been working on this for 4 days now without reaching a meaningful conclusion. Nearly forgot to mention, there is a part in the engine compartment that is buzzing whenever the key is turned ON, I believe this is the ICV and that buzzing is what I want??

lindol · « **Reply #85 on:** April 28, 2009, 11:25:41 AM »

Forgot to mention in my previous post that the fuel pump did work when I removed it from the car and applied 12V to it.

CCE30 · « **Reply #86 on:** September 02, 2009, 10:27:00 PM »

Bringing this thread back up.

Disclosure: I have a little experience wrenching on E36s and E46s, but in no way consider myself a "mechanic." Bear with me.

I recently took possession of a 1991 318i. According to the previous owner, the car "suddenly died" and has not been able to restart since. He originally thought it was the timing belt, but discovered that nothing was wrong with it. He put the car back together, and decided he did not want to work on it. And now it's mine.

I've been reading the various forums regarding no start issues, and have discovered this is THE thread for this topic.

I've only had the car a few days and have not had much time to work on it.

1) Checked for spark on #1 coil (but did not check the other 3, should I?) There is spark.
2) I took the cover off of the fuel pump and can hear it working when I crank the car.
3) I am unable to smell gas from the exhaust.
4) Battery is fully charged.

My next diagnostics tests will be the CPS and CMP. I used my 5mm allen wrench to pop out the CMP today and discovered it to be coated in oil. Is that normal? Also does testing it require that pull it out, or should I leave it bolted in? Where should I make contact with the sensor to test it?

- If the fuel pump is functioning, but I do not smell gas from the exhaust, could it still be a fuel issue? A clogged fuel filter, perhaps?

- My friend suggested I drip some gasoline into the spark plug holes to see if it will turn over. Is he insane?

- The spark plug wires are in the order of 4-3-2-1 (4 starting at the windshield). I've read it might be 1-3-4-2, but the wires are not long enough to reach. What is the correct order?

Again, I'm sure these are really dumb questions, but any help will be greatly appreciated.

romeomike · « **Reply #87 on:** September 03, 2009, 01:50:51 AM »

Wire order is 4-3-2-1 (firewall to radiator). If the wire order is correct, the car knows how to do the firing order (1-3-4-2).

Once you get past the visual inspection for broken or badly frayed crank/cam sensor wires, the testing is done at the electrical connector end with the resistance settings of a multimeter. For your own sanity, mark which one is which. If the crank sensor is defective, your car won't start.

I've changed relays and a fuel pump to cure no-start issues, with the relays being the easier and far cheaper part to try replacing first:

http://www.m42club.com/forums/showthread.php?t=9396&p=77151

Unlike our M20 brethren, the M42 relays in the picture are on the firewall under a long black plastic cover. The M20s are under a short black cover just forward of the left front strut tower.

CCE30 · « **Reply #88 on:** September 03, 2009, 10:13:05 PM »

Thanks for responding Mike.

I removed the Camshaft Position Sensor and tested it. 600Ohms.

I hope this is the problem. It should be 1250, correct?

Now to find a good one to borrow and test . . .

romeomike · « **Reply #89 on:** September 04, 2009, 12:37:53 AM »

You correctly found the fuel pump and the relays. In your photos of the sensor, its wiring, and your measurements, you have to do it at the black plastic end with the ignition off (just saw your last post -- looks like you figured that out).

If you're curious that your multimeter is working properly, ensure you have a fresh battery and your leads are seated properly. You can buy some resistors at Radio Shack and see how close your reading is to what's printed on the resistor package.

When you undo the black plastic connector, you'll see three terminals on its back side. Set your meter to resistance mode (2000 ohm scale) and put them across 1 and 2. For the "cam" sensor, a valid reading is between 1150 and 1410 ohms. For the "crank" sensor, a valid reading is between 490 and 590 ohms. Terminals 1 and 2 are the only ones that will give a valid reading. 1 and 3 or 2 and 3 will yield a 1 or OL (as in out of limits -- infinite resistance).

For what it's worth, the cam sensor goes on the upper connector, and the crank sensor on the lower. In other threads, crossing those two up leads to a no-start condition.

Adios for now,

RM

Author Topic: fuel pump/non-start issues - been doing lots of research, still NEED HELP... please > (Read 44137 times)

rt325

rt325