Author Topic: Another No Start... (Read 4935 times)

chade7320 · « **on:** October 05, 2011, 03:35:02 PM »

I have a 1991 318i with a no start issue.

Heres what I have so far...

Stomp Test throws no codes

New OEM Fuel Pump

Pumped out old gas and put in new

Pump Runs while turning car over (does not prime?)

Starts on Starter Fluid but dies when it runs out. While running has a smooth idle.

I pulled a plug after starting on starter fluid and it was dry.

Car sat for about a year and a half, it supposedly ran before it was parked and when he went to start it a few weeks ago didnt start. I just bought it to restore about a week ago.

I have a new fuel filter but havnt had time to do that one yet. Is it possible that it is so clogged fuel cant get though (when I pulled old pump, pick ups were clogged with gunk)?

All other suggestions welcomed....thank you.

DesktopDave · « **Reply #1 on:** October 05, 2011, 04:17:26 PM »

If the pick-ups were clogged, flush the tank, change the filter, clean the injectors & fuel rail. Check the fuel flow after it's buttoned back up. The fuel system must be clean enough to eat off of.

There's another problem that can cause this...bad crank angle sensor. Test it by checking resistance. Should be around 650 ohms, give or take 50. The cam sensor should be about twice that, 1280-ish.

These cars are famous for this fault...DME can't see a signal, kills the fuel pump relay...sets no codes. You can test the fuel pump by pulling the relay and jumping pins 87 & 30 IIRC. If the pump turns on when the key is in position II, it's most likely the crank sensor.

If you ever run into a later e36 M42 with the same trouble, check the DME for water damage. They tend to flood after heavy rain or power washes.

chade7320 · « **Reply #2 on:** October 05, 2011, 07:26:32 PM »

It could still be crank sensor even if I hear pump running while turning over car? Voltage at pump harness reads 12v while turning over and around 2 volts with key in position II if that helps at all?

chade7320 · « **Reply #3 on:** October 06, 2011, 09:45:34 AM »

Checked the Relay, ran the jumper and pump turned on and ran. Car still didn't start with the jumper in place.

DesktopDave · « **Reply #4 on:** October 06, 2011, 04:01:05 PM »

Good that the CPS and FP relay are tested...that's out of the way. What was the "gunk" on the pickup? If it's jammed the fuel pressure regulator open, or plugged the injectors, you won't get enough fuel pressure to start it.

chade7320 · « **Reply #5 on:** October 18, 2011, 07:55:56 PM »

Im not sure assume it was just from it sitting for year and half.

DesktopDave · « **Reply #6 on:** October 18, 2011, 08:23:03 PM »

I'd get some tests done on the fuel pressure. Clean out the tank & blow out the lines, maybe it's just a plugged filter?

SpartanE39 · « **Reply #7 on:** November 30, 2011, 01:54:13 PM »

Hey all, I am new to this forum and the E30, but have had an E39 for 5 years or so and been around bimmerforums for even longer. I purchased this car (Mentioned above^^^) from chade7320 last week and accidentally ran into this thread. Just to refresh it is a 1991 318i sedan. I am no professional mechanic by any means but I do enjoy working on my cars myself.

I have been trying to pick up where he left off and haven't been able to make a whole lot of progress. Here are some of the things that I have done so far...

First off I had to change around the plumbing and wiring on the fuel pump because it was installed incorrectly (no fuel was making it to the fuel filter on starting even though it was running). I have replaced the old fuel filter, cleaned out the fuel lines with an air compressor and have now confirmed that fuel is indeed making it to the engine while trying to start.

While troubleshooting, we came across a rats nest of wiring from a P/O when they installed an aftermarket alarm at some point. My friend who is very good at wiring cleaned it up and got everything back to factory, still no start.

The battery and wires in the car are new and the spark plugs look clean'ish so the spark appears to be good.

When trying to start the car we are not hearing any of the fuel injectors click.

I have just completed a stomp test and got the code "1444" which apparently means "No failure".

So my problem now is where to go from here. Would the DME throw a code if it was fried? And how likely is the crank sensor to be the issue if the fuel pump is working properly?

So at this point I am kind of stuck, thanks in advance for any help you can throw my way...

DesktopDave · « **Reply #8 on:** November 30, 2011, 04:02:15 PM »

I'll bet the crank sensor & pump are OK. I'd test the crank sensor just to see if you were getting the necessary 700-ish ohms. Cam sensor is easy to test too...about 1300-ish.

But the pump is sending fuel to the rail, so likely that's all OK.

The injectors on the Motronic fire in batch mode by the DME grounding the circuit. So I'd check power to the injector loom and maybe try a 12v test light on one of the connectors to see if the DME is firing them.

SpartanE39 · « **Reply #9 on:** December 01, 2011, 09:43:19 AM »

Ok thanks for the help Dave! I will try testing those out and let you know how it goes...

DesktopDave · « **Reply #10 on:** December 01, 2011, 04:35:23 PM »

BTW, those driver transistors (in the Motronic) are durable but prone to high-mileage failures. They're pretty robust but I've seen cracked solder joints and cooked ignition drivers. I'll bet the injector drivers can fail the same way. In that case the DME would think everything was OK, but it'd definitely cause a no-start.

SpartanE39 · « **Reply #11 on:** December 05, 2011, 07:14:39 PM »

Well, just replaced DME with a known working one and same result. Ran tests on both crank and cam sensors and got results close to what you mentioned.

Next step I guess is to check the injectors and related components and see whats going on there. Work on the E30 is slow due to final exams and graduation next week...

Thanks again for your help on this!

SpartanE39 · « **Reply #12 on:** December 21, 2011, 01:30:19 PM »

Ok this is getting to be really frustrating! But here's an update...

First we tested the injector loom with a noid light to see if they were getting power, which they are. Then I Replaced all vacuum lines, intake boot, removed fuel injectors from the fuel rail and cleaned them per the DIY from Pelican Parts site. Still wont start!

Could the injectors be so clogged even after being cleaned (Shade tree cleaned) that they wont allow the car to start?

I know I am getting fuel to the rail, am waiting on my buddy to bring me a fuel pressure gauge tomorrow at work to test pressure to get actual psi.

I need to get this thing running so i can get it out of my buddy's garage...

DesktopDave · « **Reply #13 on:** January 04, 2012, 08:03:25 AM »

Sorry, that last post was caught by the spam filter. Did you make any progress?

I'd figure at least one of those injectors has to open, especially at cold start as they inject roughly twice as much fuel.

Did you test the spark and double check the firing order? It's easy to get the loom mixed up with those coil packs. I'd test the coil harness to the DME plug just to be sure, then mark them then install properly 1-2-3-4 from rad to firewall.

SpartanE39 · « **Reply #14 on:** January 06, 2012, 11:28:50 AM »

The good - I was able to get the car started finally! After testing the fuel pressure, I was able to determine that the fuel pump was moving fuel, but not enough to even register on a fuel pressure gauge. So I ordered a new Walbro pump, did a little modification to adapt it to the housing and she started right up!

The bad - Now it will start, but will only run for a few seconds if I dont give it gas. So at this point I'm going to start off with replacing the rats nest of vacuum hoses under the intake as well as installing pull-apart salvaged Mustang injectors and new NGK plugs. I've also borrowed a compression tester from my buddy, so hopefully that goes well.