318i just quit running randomly

oh also, I just did my first valve lash adjustment. ummmm. I hope I didn't screw it up LOL.

Each valve was very tight at 0.004" (as far as I could tell) while bentley specs are 0.008". r3vlimited guys seem to think that the bentley spec is too loose so I went for 0.007". Who knows. Busted my ring finger and now I have a nice blood blister under my nail. Where's that sweet video of the guy burning a hole through his nail with all the blood gushing out? Always wanted to try that. Maybe I should be a doctor...

I'm about to go buy some fresh plugs just for the hell of it.

Just throwing it out there....is the timing set correctly? (I know it shouldn't have changed).

Idle Control valve?

Luke wrote: Just throwing it out there....is the timing set correctly? (I know it shouldn't have changed). Idle Control valve?

I'll try to check these two things tomorrow. An engine needs four things to run... fuel, spark, compression, and timing. I have concretely confirmed one (compression) and will be attacking spark and timing tomorrow.

I need to check fuel pressure to confirm fuel...

Do you all suggest getting a permanent inline fuel pressure gauge, or an external temporary hookup testing gauge? Budget is the name of the game, but when dealing with fuel I don't want to cheap out too much.

See the info in this thread...particularly post #2:

Cold Start Valve?

HTH

Just replaced the plugs. Also checked spark at all four wires with a brand new plug. Spark is great.

So just to recap:

1. 1985 BMW 318i
2. L-Jetronic fuel injection
3. M10 motor

Car ran awesome, drove it around the block several times over the last few days with zero issues (other than a hunting idle).

I drove it up on ramps and cut off the AC compressor belt and after that it would start and run incredibly rich. Light black/gray smoke out the tailpipe and stinking to high heavens of gas. It stopped working between starts.

So far I have checked:

1. Has compression (165 psi cold on all four)
2. Set valve lash (was consistently set to about half bentley spec)
3. Has good consistent spark on all four cylinders
4. Cap/Rotor/Wires appear to be fairly new
5. Battery is 11.5v with the key off, but even if I jump a running car to it, nothing changes
6. Coolant temp sender(s) and Thermo Timer switch both pass bentley tests

When I pull the oil fill cap off while running nothing changes (supposedly this is a test for something according to bimmerforums users but I'm not sure what). It goes from running like poop to running like poop.

Taiden wrote: When I pull the oil fill cap off while running nothing changes (supposedly this is a test for something according to bimmerforums users but I'm not sure what). It goes from running like poop to running like poop.

You have a vacuum leak somewhere. Pulling the oil fill cap creates a large vac "leak" - if your car doesn't run any worse with that change then you've got a vac leak already.

here is just a suggestion. charge the battery to full capacity 12.5V minimum. disconnect it entirely from the battery cables and disconnect the battery cable from the junction block side too (passenger side engine compartment at the firewall). bring the battery to the front of the car and hook up a set of jumper cables to it positive side to the power block (be sure to isolate the block and cables from touching the body) and negative to a good ground. try to run the car and see if this helps. 11.5 is NEVER a good voltage for a battery and if it isnt getting higher (recharging when running) i suspect it isnt very well connected to the electrical system, or it has a bad cell. if it isnt well connected, even a jump (presumably from a connection at the battery) wont get consistently good voltage to the parts where it is needed (like sensors and the like). hooking it up to a charger and charging it to capacity will tell you if it is a bad cell.

pigeon wrote:

Taiden wrote: When I pull the oil fill cap off while running nothing changes (supposedly this is a test for something according to bimmerforums users but I'm not sure what). It goes from running like poop to running like poop.

You have a vacuum leak somewhere. Pulling the oil fill cap creates a large vac "leak" - if your car doesn't run any worse with that change then you've got a vac leak already.

+1

on my 325 the hoses from the cold start injectors to the throttle body went bad and made this problem. another popular location is the underside of the intake boot between the air box and the throttle body

Just swapped in a new battery that was just put in my VW. It happens to be an identical size and is 95% the CCA rating of the BMW battery.

No difference.

I am beginning to agree that it's a vacuum leak.

I'm going to need therapy after I deal with these vacuum hoses.

Here goes...

Also I just want to thank everyone for the ideas and helping out. I wrench alone and having a second flow of ideas helps a huge amount.

Wait a minute... How could vacuum leaks make a car run pig rich?

Check the vac line to the fuel regulator...

It is brand spankin new.

I'm just about to go buy another AC compressor belt and see if that was it. I know it make NO sense but that's the only thing that fits any cause and effect theories.

Ghetto vacuum leak test: get a can of carb cleaner and spray near the suspect vacuum hoses, when the idle goes up you found the leak.

Josh wrote: Ghetto vacuum leak test: get a can of carb cleaner and spray near the suspect vacuum hoses, when the idle goes up you found the leak.

I'll be completely honest. This has never worked for me! :(

However, I did hook up my fancy snap on vacuum tester.

4-3 in. Hg at idle. Normal is 15-22

Bentley says:

1. A rich condition will cause this (thanks Bentley!)
2. Severely retarded or advanced timing (says to check timing with car warm, thank's Bentley!)
3. Large intake leak...

So my large intake boot has a couple small cracks that dont go all the way through... however it does have a large amount of dark oil / light brown stuff? Right now I have it dripping out into a pan.

Taiden wrote:

Josh wrote: Ghetto vacuum leak test: get a can of carb cleaner and spray near the suspect vacuum hoses, when the idle goes up you found the leak.

I'll be completely honest. This has never worked for me! :(

Eh, it worked when I had a leak in that intake crap hanging off the front of the SE-R's engine, but then again it's always a pretty safe bet that that crap leaks.

Do you have a valve cover vent that plumbs into the intake boot? Can you just put a breather filter on it and seal up the intake boot?

Josh wrote:

Taiden wrote:

Josh wrote: Ghetto vacuum leak test: get a can of carb cleaner and spray near the suspect vacuum hoses, when the idle goes up you found the leak.

I'll be completely honest. This has never worked for me! :(

Eh, it worked when I had a leak in that intake crap hanging off the front of the SE-R's engine, but then again it's always a pretty safe bet that that crap leaks. Do you have a valve cover vent that plumbs into the intake boot? Can you just put a breather filter on it and seal up the intake boot?

No can do boss. Supposedly if the valve cover gasket leaks it will make the motor run like crap. Introducing a ginormous leak via breather filter I imagine will make things worse.

Seriously missing my japanese motors right now. :(

Taiden wrote: Wait a minute... How could vacuum leaks make a car run pig rich?

The sensors tell the chip that the motor's getting more air than it really is getting (through the leaks), and the chip richens the mixture. Stock stuff's not like Megasquirt..it reacts to what it "sees", rather than doing what you tell it to do.

Again, vac leaks a PITA to chase down, since you've gotta check what seems to be a mile of plastic & rubber by hand..

Alrighty. Well, I pulled all my vac stuff yesterday and checked everything with my vacuum tester. (tested to 25 in. Hg) I have about ten hickies in various places on my body in standard vacuum hose sizes. Good thing I'm single.

There were a lot of cracked or expanded ends on most of the hoses. I'm heading to NAPA in a few minutes to try to find some of the more bizarre ones.

OK. All vacuum lines/hoses and the intake boot are mint. All tested to 25 in. Hg and pressure tested with soap in a spray bottle.

Car still runs like E36 M3. 5 - 3 in. Hg at idle, bouncing around.

The good news is when I figure out what it is, this thing is going to run MINT!

Did you pull the plugs and clean the soot off them right after fixing all the vacuum lines, or might they still be all fouled up?

I'll check them out. I literally just bought an AC belt to see if that was it. If it was I might die a little inside.

Plugs are fine. When I take out the fuel pump relay, the car runs smooth until it totally dies. I think this confirms my belief that the car is squirting asinine amounts of fuel, since when I force it to lean out it runs amazing.

Perhaps my fuel pressure is through the roof. I really hope I don't have the same issue that the GRM spec e30 had. Dropping the tank in my driveway is a huge turn off for me.

Oh, and unplugging the cold start valve does nothing for this rich mixture.

maybe the FPR itself is cooked. How does one test that, anyway, short of swapping parts?