Is my engine really at TDC?

[deQuincey]

david, you will love these pictures of my old flywheel

your flywheel does not have a ball, but a single mark, see here how is arranged next to the letter Z

honolulu, i assume that the circle is not a fraction of the ball, but the "O" letter from the OT sign

i made a check, and more or less it is located at 22degrees

this info comes from my old thread:

http://www.e9coupe.com/forum/showthread.php?t=12400

 

[Stevehose]

So if you set your advance strobe gun to 32, bring the rpm up to 3500, you should see your white line, not the "z" mark. Then your all in timing is confirmed. Once this is set you can then lower the rpms a couple hundred at a time, lower the strobe gun advance setting until the line shows, and note that number from the gun. Keep doing this back to idle and you will have your curve, and also be able to see if your distrib is maybe not advancing or functioning properly at the rpms where the engine misfires. I believe this would eliminate or confirm the dist as a possible cause.

 

[m5bb]

At the risk of cross-posting, do either of you know where I can get the advance curve for an 0 231 184 008 distributor? Its not listed in the blue books. Mine has retard and advance.

If you know what motor it goes on you may have better luck looking it up with the motor specs?

 

[David]

Thanks guys.

Honolulu, the small circle in the flywheel photo is part of OT, not a ball. I time using the hash mark just below OT.

deQuincey, thanks for the photos. Your extensive use of photos in your posts is always very helpful. I really wish we had a way to store these photo essays on our own sever so they live on. I don't think I have the stock flywheel.

m5bb, it's a stock engine, but I don't know the source of the distributor. Strange that I cant seem to track it down. It's not listed in the Blue Books.

Steve, here is the curve I created. I still don't have the correct curve but I did find one for a Bosh 084 which looks close-, but I'm not sure if that's good or bad. I ran my curve by myself so Im guessing the curve would be smoother if I had help. It's not easy trying to set the RPM with your left hand and check the RPM and adv with your right leaning into a motor running at 3500 RPM. This is with the adv connected (from the carb to the distributor). Retard off at the distributor, carb and manifold capped.

With TDC confirmed all around, and this curve looking close (I think), that leaves the carbs to investigate. Ill pull the plugs and post.

Thanks again to all of you.

 

[Mike Goble]

This is with the adv connected (from the carb to the distributor). Retard off at the distributor, carb and manifold capped.

With TDC confirmed all around, and this curve looking close (I think), that leaves the carbs to investigate. Ill pull the plugs and post.

If you want to check the distributor mechanical advance curve, disconnect the vacuum advance/retard.

 

[Stevehose]

Yes the lines to the distrib should be plugged. Also, You can get a longer screw to replace the existing idle screw so you can make accurate adjustments at higher rpm. I have one for mine, when done I replace it with the stock shorter one.

If you want to check the distributor mechanical advance curve, disconnect the vacuum advance/retard.

 

[61porsche]

mmmm

Distributer timing is at camshaft speed= 2 times crank speed. Don't time at 3500 from your earlier post.

Go back and time at 1700 rpm+- 50. That's when all your mechanical advance should be in.

An 008 distributer is a BMW replacement for a 02 Ti. How you got that with a 6cylinder cam is a mystery. Heard of it from the old speed boys; like bigfoot.

Find a proper distributer or pay someone to blueprint it.

Mystery flywheel,- use the tdc, then turn back 11 teeth and mark it. That's your true mark.( OK- that assumes your harmonic balancer hasn't shifted on it's rubber ring. The first thing to check.)

 

[Mike Goble]

Distributer timing is at camshaft speed= 2 times crank speed. Don't time at 3500 from your earlier post.

The distributor runs at half the crank speed.

 

[David]

Also, You can get a longer screw to replace the existing idle screw so you can make accurate adjustments at higher rpm. I have one for mine, when done I replace it with the stock shorter one.

Nice. That's the tip-of-the-weekend.

 

[David]

Distributer timing is at camshaft speed= 2 times crank speed. Don't time at 3500 from your earlier post.

Go back and time at 1700 rpm+- 50. That's when all your mechanical advance should be in.

An 008 distributer is a BMW replacement for a 02 Ti. How you got that with a 6cylinder cam is a mystery. Heard of it from the old speed boys; like bigfoot.

Find a proper distributer or pay someone to blueprint it.

Mystery flywheel,- use the tdc, then turn back 11 teeth and mark it. That's your true mark.( OK- that assumes your harmonic balancer hasn't shifted on it's rubber ring. The first thing to check.)

The wrong distributor....that makes perfect sense for this car. But I think Bavauto is showing it for my car. Almost $600. 0 231 184 008.

Took the car for a drive. It doesnt diesel when I turn it off now and the idle is a little better, but it has no guts. It's like driving in mud. Too bad since I found some fun roads in Rancho Santa Fe.

 

[Mike Goble]

Rancho Santa Fe? I'm in San Marcos for about 4 more days, then I'll be back after the 23rd. PM me if you would like some assistance in getting your timing/carb problem solved. I'll drive my Bav over there and we can compare things. This stuff isn't rocket science.

 

[David]

Mystery flywheel,- use the tdc, then turn back 11 teeth and mark it. That's your true mark.( OK- that assumes your harmonic balancer hasn't shifted on it's rubber ring. The first thing to check.)

This is confusing to me. Why isn't the factory set TDC (OT) the true mark ?

 

[Stevehose]

Are you using points or electronic ignition?

Did you check the secondary barrels for leaks?

 

[m5bb]

This is from an earlier post in this thread by me m5bb and sfdon gave the answer below and he was right.
You may have a Motronic motor which originally had fuel injection.

Appears you could have a flywheel from a manual Motronic 1.1 engine.
That raised area is the TDC section that is read by one of the 2 magnetic position sensors on the bell housing. As a guess, I would say that it is about 120 degrees away from the window where you would look for the T l O mark that is on the flywheel for normal timing purposes. Set your front dampener correctly and then paint the TO mark on the flywheel. Count 7 teeth from there to have the correct mark for setting your distributor and paint that spot too.

 

[David]

I really appreciate all the help, but boy am I'm having a hard time following this.

From that earlier post, 7 teeth from OT was to find the Z mark to use for timing. But Im timing off of the OT mark with an adjustable advance strobe-so I didnt think I really needed to find the Z timing mark. My OT mark lines up with the damper and cam.

For what its worth, I may indeed have had a motronic flywheel and housing put in when I did the 5sd conversion. Ive always thought the motor was the stock US carb model but I suppose I should try to confirm that.

 

[David]

Are you using points or electronic ignition?

Did you check the secondary barrels for leaks?

Petronix. How do I check the secondary barrels for leaks ?

 

[sfdon]

Send me a pm if you need help on this- I will be in LA in a few weeks.

 

[Stevehose]

Is your Pertronix correct for your distributor?

For the barrels, put your hand over the secondary at idle to see if there is any change in idle speed. You can also squirt carb cleaner in there and see if it drains quickly or slowly. Also ensure they are not stuck closed and activate at the proper time via the linkage.

Are your carbs Zeniths or Weber replacements?

Petronix. How do I check the secondary barrels for leaks ?

 

[sfdon]

I have to ask- did you use /keep the metal pin or dowel in the crank to clock your flywheel properly?
Have you tried turning your distributor to the left 20 degrees?
Was there a small pin on the front crank flange?
Is your engine running hot?

 

[Peter Coomaraswamy]

David, I'm having the same problem, I'm trying everyone's suggestions, still popping, running rough and/or driving through mud. I'll race you to the solution, but I'll post anything positive I find. I replaced the spark plugs with NGK's (per forum suggestions) checked all the wires through the cap, made sure I did not reverse the firing order. I'm going to go back to the points to see if I did something wrong with the Pertronix install, though it seems pretty idiot proof (doesn't protect me).