924Board.org

[kris]

Okay!!! I am in a little better mood now that my project is progressing some more.

After putting the throttle body back on my 81/931 & putting the rest of the motor back together, I was still getting the same stalling out problem. The car would start, run for a second or two...sputter badly...then die as soon as the throttle body was cracked. SO, needless to say the fenders were about ready to require body work as I was to the point of kicking the damn thing!

So after brainstorming for a bit, I decided to check a few things (some double checked too):

Adjustment of the CIS:
The first thing I did was question the mixture of the fuel. The car would smell strongly of gas from the exhaust while attempting to get the car to stay running (I think I burned out all my nasal hairs this afternoon). So I decided to play with the air fuel mixture control next to the fuel distributor (I mean what do I really have to lose at this point by screwing it up right!?!?). After playing with it for awhile, and turning it all over the place. I decided to grab another unit that I had on the shelf & take it apart to see where the thread was lined up inside it (using it as a point of reference so to speak). It appeared to be about three thread lines over the lip of the studs housing. So I adjusted the one in the car accordingly...WOULDNT YOU KNOW IT! THE CAR STARTS & STAYS RUNNING!!... I MOVED THE THROTTLE & IT WOULDNT DIE AT ALL!!!!

Needless to say, "IM HYPED"!!.....HOWEVER, I play with the throttle & it is still missing a little bit upon acceleration. BUT IT DOESNT DIE (running 5 times better though)!.. I went ahead & tried to tune it a little bit, but I was still getting a "raw fuel smell" from the exhaust and some black smoke too (black smoke is an indication of fuel so I understand). So my thinking, is "ok, problem solved, but the mixture is just too rich." So I decide to lean the mixture out slowly in hopes that it will clear up the "stall out" I am getting while trying to accellerate the throttle cam. NOPE!!!... As I lean the mixture out, the car starts doing the same shit again (wanting to shut down & not run). And no matter what adjustments I make to the mixture unit, I still cant get a steady throttle response from the motor...it ALWAYS misfires while trying to accelerate the motor speed. So I enriched the mixture upto the point where the car will continue to run at an idle speed without stalling & left it at that for now.

Timing:
The next thing I did was elect to RECHECK the timing. The ingnition distributor mark was lined up straight on the rotor to the number one position, the cam pulley mark was lined perfectly with the top of the valve cover mark & the mark on the flywheel was visible too on the back of the motor.... NOW THE STRANGE THING! When I connected the timing light to the number one spark plug wire & fired up the motor, I was getting a PERFECT reading on the camshaft mark (DEAD CENTER), then I would go to the flywheel & hit it with the timing light & the mark on the flywheel was no where to be seen!! (WHATS UP WITH THAT???...ANYONE HAVE ANY IDEAS HERE??)....

Anyone have any suggestions before I continue onto chapter 2?

[Smoothie]

For checking TDC on the crankshaft, there's also a notch on the pulley and a pointer on the oil pump - view with the timing light from top-left-front of the engine and see what you can see. Put a dab of white paint on the v-belt pulley's notch first.

[kris]

Okay.. I will do that tomorrow then.

Now when I do this, if the timing is off mark on the crank shaft pulley/oil pump, then how is this possible, and how do I adjust it? The 81-82 931 models have the electronic ignition, and the timing is supposed to be handled by the DITC unit correct?...meaning no mechanical adjustments can be made to compensate right??

Could it be possible that the ignition distributor is lined up perfectly with the camshaft, but the crankshaft (and the piston cycling) is not in line with the ignition & valves (this puzzles me since the flywheel lines up okay with everything else when the car is not running)??

If the timing belt slipped ONE notch on the crankshaft, would that cause the flywheel mark to not be visible during a timing test? Could this also cause trouble in acceleration of the motor & trouble adjusting the enrichment of the Lamda CIS system?

[Lizard]

it could cause that yes to all the above although it probably retarded it one or 2 notches I think if only 1 notch you could still see it, although how can you view the mark on the flywheel? do you have the engine out or are you talking about the crank pully, this might be a good time to do the timing belt in the car

[Smoothie]

Right - no timing adjustment with DITC.

It is possible for the flywheel to be put on wrong - there are 6 different positions that it could be installed in and only one of them is correct. Just re-check the valve timing with the engine not running, but use the timing mark on the v-belt pulley on front this time - the pulley can only be installed one way, so it'll be right. Once lined-up take a look back at the flywheel again to verify whether or not it's installed right.

The correct mark to use on the back of the cam pulley is a dot with lines on both sides.

The distributor should be aligned so the clips go front-back (one clip directly to the front, the other one directly back) and #1 plug post is at the rear-right as viewed from the front. Firing order: 1-3-4-2

"If the timing belt slipped ONE notch on the crankshaft, would that cause the flywheel mark to not be visible during a timing test?"
Yes, but if the timing marks line up, the crank pulley hasn't slipped a notch.

[kris]

The mark on the flywheel is viewable from the drivers side of the car when looking down toward the clutch housing with the motor IN the car. The timing mark on the fly wheel is indicated with a "Z1" & a line underneath it (pictures on page 289 of the haynes manual).... This is the mark that the manual states that you use when lining the #1 piston to TDC.

So if the belt slipped off of the lower pulley gear, can it be adjusted on the camshaft pulley? I would think that would be ok since the distributor turns WITH the camshaft & that would basiclly be the same as adjusting it on the lower crank pulley gear....

[Smoothie]

The usual (only) way is to have the belt wrapped around the lower pulley first, then slip it onto the cam pulley. Have the marks lined-up when you do this and you're set.

[kris]

Well, the flywheel doesnt appear to be installed incorrectly actually. as stated above, the mark IS VISIBLE when the car is NOT running (If it was on incorrectly, it wouldnt be visible AT ALL I wouldnt think). It just decides to diappear when the car is running & I check it with a timing light (I am going to go ahead & check it on the front side though as suggeted & see what happens)... Everything lines up though..... cam pulley to valve cover mark....the mark on the flywheel is visible & the cap rotor lines upto the distributor mark (the distributor IS on correctly as I had to adjust it already)..

Should the timing be set to the blue dot when the car is off? That is what my assumtion was. And that is where it is set... It also marks the blue dot when I hit it with the timing light.....

If the belt slipped just ONE notch, then you could still see the mark through the window on the flywheel I would think. Its a fairly good sized window, and it would appear that a "one notch slip" would still keep the mark in the window with the car shut off....but then again, weighing the size of the front crankshaft gear pulley, it might not.... So I will assume it has NOT slipped.

But that still brings me right back to the start (passes go & collects my $200)!

Why wouldnt it be visible then during a timing check if it shows up when the car is off? Im starting to think maybe the DITC Unit I got is bad....

*RIPS MY HAIR OUT*

Im glad I have ALL DAY TOMORROW TO WORK ON THIS THING

[Smoothie]

Your belt isn't slipped a notch. That 1/4" or so between notches on the crank pulley translates to a couple of inches difference on the flywheel because of its' larger diameter. If you were slipped a notch, the mark wouldn't be visible through the flywheel window.

When the engine is running, DITC alters the timing, so you won't always see the timing mark through that window with a timing light.
"Should the timing be set to the blue dot when the car is off?"
I don't know - I don't have colored marks on my car, like I said before, the correct mark should be a dot with lines on both sides.

Have you replaced wires, dist cap, rotor, plugs?

[kris]

I replaced the plugs with NGK B8EV Plugs & gaped them at .65mm..

I didnt replace the plug wires or cap or rotor. But I did check the resisitance on them. I had a 2.2 Ohm resistance on all the plug wires, and a 0 ohm resistance on the cap & rotor.. The manual says the plug wires should have a 6 ohm resistance. When the wires go bad, with the resistance on the wires DECREASE? Would TOO MUCH current through them cause the plugs to miss?? This would surprise me if so...

Chris

[Smoothie]

Well, looks like you're ok with valve timing, distributor, wires, plugs, cap, rotor... Given that 12 pin connector on the DITC a wiggle or unplug/replug?
Thrown in a bottle of drygas?
Air filter pretty clean?
Tested the coil?

[kris]

I have pulled the DITC Unit out about 4 times already put it back in. So yea the plug has been jiggled ALOT. Also cleaned the terminals off of the DITC unit with a metal brush last time I installed it.

Coil, I havent checked that yet. I will check that today as well...

What is "dry gas"?

As far as the air filter goes, I have done several of these tests without the air filter & the airbox cover on the car (and with it ON the car...same results both ways). I know thats probably not the best idea in the world, but I am just trying to get the car at a smooth acceleration, then i was going to put it back on. I was also doing this so I could keep an eye on the sensor plate on mixture control unit. One thing about this may shed a new light on things is the reaction I am getting from the sensor plate. Everytime the car "stalls" during acceleration, the sensor plate will "jump" up into the horzontal position (closed) making a "popping" sound. It does this repeatably. This would make me think that the car maybe getting a lack of air during the mixture cycle causing the car to "flood" or making the mixture too strong & giving me the smell of "raw gas" exhaust. Any thoughts on this theory or what I might need to look for to resolve the matter?

[Smoothie]

Could the metering plate be sticking? Make sure it's perfectly centered.

Dry gas: aka "gas drier", "fuel line antifreeze", etc. Basically methyl alchohol added to gas to cause any water in the tank to mix with and burn with the fuel.

[kris]

I took the distributor off of the car & the plate moves freely. I also have a 0.010mm gap all the way around the plate (evenly). Its not sticking at all that I am aware of. The plunger inside of the distributor seems to move freely as well. It takes a second or two for it to slide out on its own, but this I would think is normal since it is a pretty snug fit...

Im thinking of tearing into the O2 system. Checking the O2 Sensor & the Frequency valve. If the Lambda system is similar to the 924 n/a CIS system, then maybe the O2 Sensor is bad & telling the Computer that in turn relays data to the frequency valve that the car is getting too much fuel & it is cutting the fuel back while Im accelarating....WHO KNOWS!! I am gonna go mess with it & see what else I can find...

[Smoothie]

Do a search on o2 sensor and frequency valve. There were a bunch of posts on the topic a while ago.

One thing I recall is if the lambda box senses a problem, it reverts to a default mode and keeps the frequency valve operating - resulting in, I think, a slightly richer mixture.