M50 E30 No Start - HELP!!!

[NEOe30]

Driving home the other day on low boost (3-4lbs), I managed to somehow blow out my spark plug valve cover seals. Yes, to clear things up, my crankcase is vented. One happened a few miles from home and the other about a half mile, so I limped her home on 4 cylinders. My gaskets were almost brand new, so when I had the time, I took off the valve cover, re-seated everything, and put some RTV in the trouble spots along with the spark plug seals. Upon reassembly, the car would not start.

The car will start for about a second and die out. I would have liked to believe it was an easy fix, but apparently not. If I keep my foot on the throttle at least 50% pedal travel while starting, the revs shoot up but the car dies immediately after. So I borrowed a TPS from another local to test if that was the problem, same symptoms. I also plugged in his ECU for the hell of it, still the same symptoms.

After surfing the web, I suspected that the coil pack ground was not sufficient since I had cleaned up and painted my valve cover when I had it off. Even after cleaning the grounding surfaces, no start.
My battery did spark a bit when I reinstalled it after the valve cover job (vert batteries are in the front, much easier to completely remove it) so I thought I may have blown a fuse or possibly the main relay or fuel pump relay since they didn't look in the best condition. No fuses were blown, and I cleaned up the relay terminals and even bought a new main relay, still no start.

At this point I began to think I may have messed up something internally on the way home, so I ran a compression test and got beautiful results.

192-187-188-186-190-188

So I ruled out any internal issues.

After this I thought I should test the coil packs for kicks and found all to be 1.0-1.1ohm, even though the Bently suggests .8, my assumption was that my multi meter was just a tad off. I even pulled the coil packs and plugs out to test them and of course, all were firing.

These results still lead me to believe I have a fueling issue, ironic since my original problem was ignition. While testing the coil packs I noticed that I had a decent size fuel leak at the fuel rail feed side, so i fixed it believing that low fuel pressure could've caused my issue, still no start.

I am led to believe that I still have a fueling issue. My fuel pump DOES prime occasionally, so I'm thinking maybe it's dying? However when I jump the main relay and fuel pump relays, the pump doesn't prime.

My final thoughts are that I have a dying fuel pump or fuel pump relay, and I'm totally unsure of how this could've happened from a valve cover job. Normally I try to avoid asking for forum help, but it's been almost two weeks and I'm starting to get frustrated after at least 10 hours of trial and error. If there's anything you guys think I may have overlooked, I'd love to hear it because I'm all ears for anything at this point. Hopefully we can get her back on the road soon and crank up the boost!

Thanks much,
Neo

[TobyB]

Yup, my thought was fuel pressure- either the pump, or the relay. Or a connection in
the 'run' part of your ignition switch, so that the pump runs in 'start' but stops in 'run'

Stick a fuel pressure gauge on it- they do wonders at ruling all sorts of things like that out.

hth

t

[NEOe30]

Yup, my thought was fuel pressure- either the pump, or the relay. Or a connection in
the 'run' part of your ignition switch, so that the pump runs in 'start' but stops in 'run'

Stick a fuel pressure gauge on it- they do wonders at ruling all sorts of things like that out.

hth

t

Thanks for your input, glad to know I was on the right track. I had heard that the CPS can control power to the main and fuel relays, so i just tested it and results came back good at 545ohm, so no issue there.

To test that my fuel pump was getting power, I plugged in all my relays and took out the back seat and hooked up my multimeter to the fuel pump harness. Sure enough when the car would start just for a second, I was getting the 12V. Also, I checked to make sure none of the fuel pressure regulator lines were blocked or kinked and we are good there as well.

With that being said, I believe my problem lies in the fuel pump since there's power all the way to it. Is this correct? I picked up a fuel pressure tester from the store and will be reporting back with results.

Additionally, since my car is swapped, the fuel pump and O2 relays were backwards. So I was jumping the orange relay, not the blue. After jumping the blue relay, I was able to get the fuel pump to prime even with the car being off, as it should. Any suggestions?

[NEOe30]

Car builds 50psi at the fuel rail while cranking and spikes 52-55 when it runs for a second. This seems perfect...Anybody?

[pazi88]

What ecu do you use? If stock read fault codes?

[TobyB]

Yeah, sounds like you have plenty of fuel to get started...

t

[NEOe30]

What ecu do you use? If stock read fault codes?

Car is m50 swapped. ECU is a Bosch 402. Motronic 3.1 I believe. I'm not sure if this prevents me from doing the stomp test (pretty sure it does) or if the PO didn't hook everything up, but I can't get it to run the test.

Also I just replaced the sparks today and the coil packs with some spares that I had. The car is still really rough and sounds like it wants to try and save itself before dying but just isn't able.

[pazi88]

I mean connect the car to PC and read fault codes using INPA for example. Or get someone to do that for you.

[NEOe30]

I mean connect the car to PC and read fault codes using INPA for example. Or get someone to do that for you.

I'm not sure how I would go about doing this, I assume I'd use the OBD port. Unfortunately I did not swap the motor so I'm unsure where the PO put it. I appreciate the help but I feel like I'm at a dead end here guys.

The only other things that come to mind is a faulty injector or maybe a huge vaccum leak I'm missing. When I keep the motor running using the gas, it's not consistent, even if I'm consistent on the throttle. This is why I believe it to be a misfire.

[NEOe30]

Okay guys so I unplugged the maf and if I give the car some gas during startup then it will idle on its own, just very rough. Plug the maf back in and the car won't idle on its own. MAF sensor need replaced?

[NEOe30]

Anyone? Would appreciate a little more input before I drop $200 on a sensor.

[Klug]

Sounds like the MAF- hit up a junkyard and find an M50 MAF laying around- grab as many as you can and see if that was the issue.

as far as running the codes- not sure with ODB1 but you can use the pac-man connector (Diag port) to run the codes.

[NEOe30]

Hey guys! After almost ordering a new MAF and picking one up on the forums I did one more once over in the car. Silly me, the gooseneck for the idle control valve had popped off and I could not see it from the top of the motor. I was very relieved after finding the issue, and apperantly it's common. I wish I would have stumbled across that info earlier, the e30 was out of commission for 6 weeks! Back on the road and boosting again, and I'm going to epoxy that gooseneck into the manifold so we don't have any more leaks.