Need Opinions on What's Next

[Sean S.]

Hey everyone,

Let me describe what is going on here and hopefully, someone has dealth with this before and can point me in a direction I haven't thought of.

A friend of mine has an 87 325i convertible. It lost the waterpump on the freeway, blew out all the coolant, but proceeded to keep driving the car until it stopped. I took it all apart and the cylinder head is cracked at #5 coolant jacket. Piston bores look good, no scoring, turns by hand, no problem. Sourced new complete cyl head, installed along with new pump, belts, etc. Now, the problem: it will not idle or stay running at all ... in order to even think about turning it over, you have to crank with the accelerator pedal buried to the floor at which point it will barely start, run like complete shit, and send just clouds of smoke out the tail pipe. I have tried the following:

Swapped all the following parts from another well running car (mine ;D)
- FPS
- MAF
- Crank Sensor
- TPS
- 2 sets of plugs (bosch and ngk)
- DME
- Coolant temp sensor
- Run the valves at .010
- Torn the front timing covers back off and made sure timing was dead on
- Distributor cap and rotor are relatively new (>6mos) and look fine
- Compression is 125 across all cylinders
- Fuel return line is clear

In addition, when I took the potentially suspect parts off, I put them on my car and ran it. All work fine, so I can deduce that all parts are functional.

I thought it may have been due to a plugged cat; I dropped the down pipes at the headers and tried to turn the engine over. Nope - same barely running condition, just a lot louder.

I have another set of plugs coming as I think these are now fouled beyond running in a good car for cleaning. I'm running out of options here and hope someone can give a few pointers.

Thanks,
Sean

[IceWhite]

Have you tried swapping coils, since there is no mention of it?

[Sean S.]

Spark output looks strong, but it's only a few mins to do so. I'll try, for sure.

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[jeffnhiscars]

Whats fouling the plugs matters as does the color of the smoke and if he actually kept driving without coolant "til it stopped" who knows what he cooked.

[Sean S.]

Plugs are fuel fouled. I mean to the point of being wet when removed. All 6. This is why I went towards the temp sensor, FPR, return line, etc.

I'm sure this engine got hot, but far from the worst one I've seen. (I remember one that just smelled like burning railroad ties, stunk up the whole shop, THAT one had gone completely Chernobyl and was unsaveable.) I'm pretty sure I'm dealing with a peripheral problem here and not the block as I would have expected no or weak compression if I had collapsed or oblong rings.

I have to switch the coils out, maybe I'll get a chance to do that tonight.

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[IceWhite]

Is the front engine lift bracket installed?

You say "- Distributor cap and rotor are relatively new (>6mos) and look fine"

Did you really swap these to and from your running car?
and did you physically check to see if they are fine, or is this an assumption due to it being >6 months old.

[Sean S.]

Yes, front hook loop is on (good thinking though!)

While cap and rotor were off for the cyl head replacement, yes, they were inspected, they appear to be fine. No cracking or strike marks, no carbon build up on conductive surfaces, no arc tracks. I suppose a cap/rotor/wires assembly swap could be in the near future.

[IceWhite]

Cool!

What is FPS?

[jeffnhiscars]

Plugs are fuel fouled. I mean to the point of being wet when removed. All 6. This is why I went towards the temp sensor, FPR, return line, etc.

I'm sure this engine got hot, but far from the worst one I've seen. (I remember one that just smelled like burning railroad ties, stunk up the whole shop, THAT one had gone completely Chernobyl and was unsaveable.) I'm pretty sure I'm dealing with a peripheral problem here and not the block as I would have expected no or weak compression if I had collapsed or oblong rings.

I have to switch the coils out, maybe I'll get a chance to do that tonight.

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Wet plugs means you are getting fuel but not spark

[Sean S.]

Yes, but I have spark ... maybe just not strong enough ... I will finally get a chance to swap coils this weekend, maybe even tonight ... of course I will let you all know the results.

I sent a reply to the above "what is FPS?", but it didnt get posted
Should read FPR - Fuel Pressure Regulator

[Sean S.]

Ok, so I swapped the wires and cap as an assembly, rotor, and coil. No difference and the "suspect" parts work fine in my car so I now know that all ignition parts are good.

I'm running real low on things left to check.

[RobDog]

I’ve had my car act the same as yours with no starts or hard starts that required pushing the pedal to the floor, just to die the second the gas is released. I had fuel and spark so diagnosing was a little more difficult. After going through just about every possibility it ended up being the fuel injectors. The car was running rich to the point of flooding. The spark plugs were fuel soaked and not providing spark. M50 fuel injectors solved the problem and the car has been running better than it ever has.

[Sean S.]

I considered the injectors, but they were all replaced about a year ago.

[lcoleman]

Fuel lines reversed?
Engine ground connected?
Mechanical problem? (out of time, bad head)

[ForcedFirebird]

Lift the fuel rail so you can see the injector tips, crank the car and watch. Sounds like you have a stuck injector, or it's being physically grounded causing a full open condition.

Also, if the car has a c109 connector, it can cause issues.