Totally stumped!

[monkeyodeath]

Hi guys, I know "won't start" threads are lame, but I have tried basically everything and this issue is still here, and I'm stumped.

I had some issues with a "new to me" '90 325i. It drove fine during the test drive, got me 30 miles to my house, and then immediately started acting up when I tried to move it 2 days later. The idle was rough, it smelled super rich (though it did smell rich during the test drive), and it would have a hell of a time starting. Hitting the throttle would cause the car to die.

So, to tune it up and hopefully get it running nice enough to pass smog, I did the following:

*Checked injectors for leakage, seemed OK.
*Checked coolant temp sensor - tests OK.
*Replaced FPR that was allowing fuel pressure to get too high. Now fuel pressure is within spec.
*Replaced totally crudded-up O2 sensor.
*Adjusted valves.
*Replaced water pump and timing belt. Checked literally 4-5 times to make sure timing was right.
*Replaced ignition wires, distributor, plugs, and rotor.
*Smoke tested for leaks (with a homemade setup but I think it works pretty well) and found one small leak, which was fixed.
*Tested ICV - OK.

And now, after all that, the car simply won't start at all now. The starter cranks happily. I have checked to verify that all 6 plugs are getting spark that looks hot and healthy. After maybe 15 seconds of cranking, I smell gas, and the plugs are wet when I pull them, but no start. I've tried flooring the gas pedal while cranking to no effect. Temperature doesn't seem to change things - I've tried it when it's cold and in the middle of the day.

Here are the things I've tried:

*Replacement DME
*Replacement ignition coil
*Replacement fuel and main relays
*Replacement CPS

None of these things have helped. I'm totally stumped at this point - I'm getting spark, I'm getting fuel, and I'm pretty damn sure my timing is right.

The only thing I can think of at this point is that the fuel pump, which seems to work fine when I jumper the relay and measure the pressure, is somehow not working well when the car is cranking or running. But then again, I'm smelling gas at the tailpipe when I crank it a lot.

Any ideas? Your help is very much appreciated.

[7pilot]

It Might help to go over all the electrical connections of all the components that were disconnected or replaced.
Check the fuses(although you do have power to the fuel pump)
Check the battery voltage and find out how much fuel is in the tank.
Check the quality of the fuel that is in the tank since the car is new to you.
Examine the connector C191 under the the throttle body for corrosion or contamination.


m

[jlevie]

Tee in a pressure gauge on the like that feed the rail and see what the fuel pressure is when cranking.

[monkeyodeath]

I looked thru the fuses and found no problems. I filled the tank with gas right after I bought it. Battery was on charger so it should be full. I'll take a look at that connector, though - had not thought of that.

If the pressure is wrong while cranking, is that a sign of a bad fuel pump, or bad electrical system?

[jlevie]

I looked thru the fuses and found no problems. I filled the tank with gas right after I bought it. Battery was on charger so it should be full. I'll take a look at that connector, though - had not thought of that.

If the pressure is wrong while cranking, is that a sign of a bad fuel pump, or bad electrical system?

The results of the fuel system tests in the Bentley will tell you if there are fuel system problems and where they are.

[cabriodster87]

Flooded? Dry the plugs with compressed air and pull pump fuse, crank the engine maybe 15 seconds, if it starts to pop over let it do that for a few seconds, then put the pump fuse back in and see if it responds. Had the same symptoms with mine, and changed the oil too. Its OK now. Good luck.

[monkeyodeath]

Just checked the fuel pump pressure while cranking and it doesn't change - pressure stays steady at what is specified by the BGB.

Took out the plugs after trying this and they were soaked - sprayed them off, put them back in, bled the fuel pressure, took out the relay, cranked it for a bit, then put the fuel pump relay back in. No dice.

[e30rapidic]

do you have another afm you could try?

[monkeyodeath]

Will try another AFM tomorrow.

I was super paranoid that I did the timing belt wrong and have bent valves because of it, though I have never actually been able to get the engine to run since doing it. I checked the clearances of all the valves, looking for signs that one was stuck open, no dice. I rotated the crankshaft to TDC and looked at the #1 cylinder's valves - both were off cam. Any other ways I can verify that the timing is right? I did everything by the book and checked a million times. The crank moves w/o obstruction.

Also, before I replaced everything, I was pretty sure the car was running pig rich, it smelled really gassy, the O2 sensor was totally crudded up, and it idled rough.

Now, it seems that in just 5-10 seconds of cranking, I'm already smelling gas at the tailpipe. Does that seem quick to you? Wondering if something is making it inject way too much gas to get it going.

I also checked the coolant temp sensor at the DME plug and the readings were fine. So I'm pretty sure it isn't a case of the DME thinking that I'm trying to start the car in the arctic.

[jlevie]

You've checked the rail fuel pressure and it is good and it sounds like the rail holds pressure after cranking. If it holds pressure the injectors probably aren't leaking and flooding the engine. You have also tried two DME's. Therefore, the cause is probably not the fuel system.

When you did the smoke test did you plug the exhaust and pressurize the intake with smoke to 3-5psi for at least 5 minutes? Those are requirements for a valid smoke test.

Is it possible that the ignition wires are not in the right order?

The CPS could be flaky or the harmonic balancer could have failed and shifted. If you used the marks on a bad balancer for cam timing the cam timing would be off and spark timing would be off. The check for that is to remove the balancer and upper timing cover, rotate the crank until the mark on the crank hub is at TDC on #1 and check the came timing marks. Then without rotating the engine, refit the balancer and see it it's marks like u.p

[monkeyodeath]

Yeah, I agree with you, the fuel system seems okay.

The smoke test was homemade, but I used a compressor to pump mineral oil smoke into the intake at 5 psi. I've used it before to find very small leaks and it seems to work well, but if problems persist, I guess I may need to take it into a shop.

I pulled the ignition wire harness apart to check and yes, they are in the right order.

I'll try another spare CPS I have around to see how that works.

I suspected the harmonic balancer as well too - I had no idea that the two parts can separate. I'll check that today.

One thing, though - the alignment of the timing mark and the teeth on the harmonic balancer on my car looks pretty much exactly like this picture: http://www.angelfire.com/blues2/bimm...ldbelt_cr1.jpg. Are those the two pieces that can get off sync?

My car has the little locator pin in the crank that indexes the harmonic balancer.

[7pilot]

What do the distributor cap and rotor look like?
Since the spark plugs have taken a good soaking from fuel, install a new set of NGK plugs.

m

[billybobjoseph]

One thing you might test is your crank position sensor. The brain needs it's signal before the car will start up. You will need a digital multimeter and some back probes.

[monkeyodeath]

I'm pretty sure the CPS is okay - I replaced it, for starters, and the car is getting fuel which I know is a good sign that your CPS is fine. I've pulled all the plugs and all of them have spark when the car cranks.

The cap, rotor, wires, and plugs are all brand new. I tried swapping in the old parts one at a time to try to identify if one of those parts were defective, but no difference.

[monkeyodeath]

One thing I should mention is that last night, I was working on the car, cranking it over with the spark plugs out to check that they were all sparking, when I heard a really loud pop. I stopped cranking immediately and saw smoke wafting out of the open spark plug hole.

The explosion also popped out the ICV output hose between the intake and throttle. Not sure what that means, if anything.