dsmith

My thoughts too, and I would swear it didn't seem like it was missing. I guess you just can't leave anything to chance.

Warm Up Regulator and Fuel Distributor are horrible things you don't have to worry about on Motronic. Air Fuel Ratio, you do.

JScott

David,

I'm having the same problems. It just happened today when I was out in the heavy rain driving around. I started to notice I was low on power and anything past 3K RPM the car was way lo on power and could barely break 4500 rpm.

So it was just the plugs? I'll be replacing those soon I guess!

dsmith

well....no. i think i helped the symptoms, but not the problem; it got progressively worse again. still not sure what it is, since i can't find any bad parts!

make sure your frequency valve is working and the fuse for the interior lights is not blown (powers the 02 brain circuit), and the relay is good.

so, i pulled everything apart this week and am replacing some stuff and checking everything else. this will be the last money spent on the CIS. if it doesn't work, it sits until i can buy carbs.

replacing due to low fuel flow on acceleration theory (though nobody can give me a test to confirm):
new:
-fuel pump-Bosch (tested too much amp draw)
-check valve (came with pump old one checked ok)
-fuel tank screen (old one not dirty at all)

replacing due to vacuum leak theory (can't get any idle change with starter fluid anywhere, so again, who knows)
new:
-airbox (old one looks to have been repaired and the seam is cracking, though i can't separate it, so who knows. it has a popoff valve, but maybe the oring isn't sealing??)
-all injector seats and seals (check pics below)
-t-body oring
-FD to mixture control oring
-mixture control to airbox gasket

Checked, cleaned, adjusted:
-cleaned a bucket of carbon out of the intake runners and heads
-drained and check fuel tank. no corrosion and fuel was clean
-checked ohms on FV, in spec at 2.8ohms
-checked AAR open at cold, closed at 12vlts
-decel valve has always been plugged off, besides i didn't have an idle or stalling problem
-cleaned carbon from t-body
-cleaned oil residue from pope hat
-cleaned varnish from mixture unit. no binding and plate is in proper position
-FD plunger is clean, no varnish, and does not bind, has a little air hiss moving up and down (ok??)
-no visible cracks from any of the various rubber cis hoses. no vacuum line issues

if none of this helps, i'll do a leakdown and compression tests

below are pics of the injector sleeves. note the carbon and the crumbled orings. all shown is what was left of my throttle bellcrank bushings. the other pic is what should be thrown in the trash LOL!

david

JScott

Do you notice a bit of a burning smell as well when you do push it hard? Unfortunately I don't have access to a bunch of tools or even a garage in my parkade so I'm hoping this is an easy fix.

dsmith

nope, no burning smell. my AFR just goes way lean. i serviced 18,000 cars and this is the second one to stump me. just a matter of time...

does your car rev freely at idle (no load)? mine does.
do you have a timing light to check advance at 6k rpms?
does it idle differently now?

JScott

It doesn't rev freely
no timing light but I can check that
It idles the same. up until 3k rpm it's basically perfect.

Man I miss my shop back home on the farm!

dsmith

Do your interior lights work (above the doors)?

dsmith

Well, got everything back together and running with no change. Runs leans, etc, etc.

I'll set it up for storage now and have to deal with it in 6mos - 1yr. Probably will have leakdown/compression done and have someone redo the cam timing/valve adjust/ignition timing/mixture and see if they find anything I've missed.

Feel free to propose possibilities.
David

JScott

FYI Dave, it was my throttle cable... Thanks for the help though!

dsmith

oh, yea, adjust your throttle linkage to make sure you have full throttle!

glad you're fixed.

dsmith

So, in conclusion, the new owner of my car gave it some professional help, and it appears I had one of the cam's timing off and a leaking accumulator. It now dyno's at 160hp at the wheels on a stock 3.0 SC motor. Oh well, I was pretty dang close! At least that result makes me less scared to own another one, but it will definitely be a Motronic car (not that that changes the timing issue).

Later,
David

Mike Murphy

Thanks for updating this thread. When you say cam timing was off, does that mean the camshaft needed to be adjusted, or just that you had to re-do the timing on the distributor? If cam timing was off, then sounds like the cams weren't aligned properly when/if new tensioners were installed?

Houpty GT

I believe my car had a similar issue on top of them many problems that were found. Amazingly the car still ran which is a great compliment for CIS, I would have to say. My car had really good compression but only had vacuum of I believe 14 inches. I believe minimum spec is 15 inches. The bentley list cam timing as a source of a low reading. Well I assume the original chain with 174,000 miles on it may have stretched some and resulted in a change in timing. This is just an assumption which I cannot confirm since the topend of the motor is currently apart. I do not remember if vacuum readings were mentioned earlier in this thread. Checking vacuum readings and cam timing may be a good area to look for some of those tougher problems.

theiceman

Very Interesting Dave. I had a quick run through your posts and did not see anything about internal engine work . CAm timng is cam timing, not dirstributor timing. Although it is feasable with chain tensioners , if they are working , I would not expect it to change the cam timing. unless someone changed the seals between the chain box and the cam tower and redid the cam timing incorectly. That would not cause un enexpected change in performance however. I would have though you noticed it right after the work. I guess the evaporator is a possibility if it affected fuel pressure but someone who is more intimate with the fuel system would know. I don't think it afects dynamic fuel pressure though.

Anyway glad it is sorted .... I'm goin with the cam timing ... but keeping in mind there is possibly more to the story

all the best Dave

ice

dsmith

Ice, you hit it. It would appear that when I replaced the seals, I didn't get the cam timing perfect. I don't know which cam or how far off, but at least it didn't leak! What really threw me off was the cat conv coming apart driving to the next race, but fixing that had no effect. Seeing how lean I was running it (on the LM1), I didn't want to pay to have the cam timing done, then still find that there was engine damage from the lean condition, etc, etc, engine rebuild, etc, etc. So, I just cut the loss. Let's just say the new owner is happy with his $8k car.

Anyhoo, on to the next race car project. A Ford Aspire with an Escort GT motor, built for the Rally-America series. My friend and I are building twin cars. We estimate about 140hp in a 2000lb car. I'm going out now to measure for the cage tubing order!

David