928toy

Hey Fellow 928 owners, my first post as a RL member.
Have a '79 928 that refuses to run. Has been at my mechanics place for months. Was running great (heard it going on the trailer when I arrived to pick it up a few days ago). No go since then, and my mechanic is away. Hoping someone has some ideas (my mech is getting stumped as well)
Car has ample fuel pressure leaving the pump and arriving up front.
Has rebuilt WUR, new timing belts, new fuel filter, new accumulator, new cap & rotor, rebuilt fuel distributor, new green wire, fuel injectors were sent away for reworking, new gaskets all around the Jetronic body, the screens into the fuel distributor are clear, the 14 pin connector was cleaned, pulse to fuel injectors good, new battery giving ample amps.
Short history - car stored indoors for past 10 yrs. Had some work done. All old fuel is gone & replaced w/high test. Dropped tank in summer to ensure no kinked fuel lines & tested pump. Car ran once at high idle (2500 rpm) left it running in driveway for 15 mins, moved it, stalled & refused to run for more than a minute. Depress accelerator, engine stalls. Then all work above was completed, mechanic took it for a drive, put it on the trailer and back to no go. Idles (just barely, but depressing throttle does nothing) Adjusting the 3 mm adjuster for the cam under the fuel distributor used to make a difference back before all the work, no it does absolutely nothing. Manually depressing the air intake flap stalls the engine. Lots of spark to the plugs, took one out - wet, but not soaked. Sprayed some quick start into the air intake while running - did absolutely nothing (like it didn't even get to the intake). Am totally stumped & $2500 poorer. Anyone with any ideas?? Sorry for the long story (hope I don't get banned!!

The Forgotten On

You won't get banned for an appropriate rant

Check your control pressures using a set of CIS gauges. They need to be set correctly or else your car will have issues such as the ones you are facing.

With all of the parts you put in, the only thing that could cause this issue is running rich from too much fuel. Next time take out all of the spark plugs to see if a few are running lean from a vacuum leak caused by a failed gasket at the base of the intake spider "legs" or a leak at the injectors.

I hope this little list of things to check helps. Happy new year

OTR18WHEELER

Bad TPS?

The Forgotten On

79's have CIS, They don't have TPS as the injection is mechanical.

medipedicman

This is something that I copied from another user and have used it on two CIS cars, both 1979. This is not a substitute for having and using proper CIS gauges, but it may improve your situation until you can properly measure.

" How to setup CIS with no gauges"
Here is how to set your mixture AND your cold control pressure with no gauges.

This will work on just about any CIS.. BUT you may not pass emissions.. though your car will be faster and driveability will go WAY up.

I did this and it worked PERFECT.. my car was a complete basket case before I did this... some will totally disagree with this and that is fine.. no reason to just post that you disagree.. this is just here for those that want to get their CIS up and running quickly and do not have gauges.. frankly, even if I had access to my gauge I would set it this way now.. its the best way to set it on an older car with vacum leaks and other things the factory did not plan for.. of course you should try and fix those things the best you can..

Okay.. first setting is hot run mixture.. you need to get your car HOT.. 180 degree's oil temp or better.

Okay, I am not going to go into how to adjust the mixture.. you can search for that.. but you need a 5" allen wrench.

Okay.. idle the car and turn the wrench all the way counter clock-wise. this should kill your car (stop when your car dies.. but DO NOT PUSH DOWN ON THE WRENCH!.. ). if it doesn't you got bigger problems and you need to stop and figure out why going FULL lean does not kill your idle... your idle should be about 900 rpm.

Okay. now, turn the mixture CLOCKWISE about 1 turn and see if the car starts.. if it does not, go half a turn until it does. Set your idle to 900 if possible.. if its unstable try going more clockwise.. get it stable.

Okay.. this is "my trick"... REV THE MOTOR a bit..

Let it idle

push down lightly on the wrench.. VERY LIGHTLY..

If the car revs more then you are too lean.. turn clockwise 1/4" turn. REV THE MOTOR.
Set the idle to 900 rpm

REV THE MOTOR

let it idle

Push down on the allen wrench.. if it revs more you are too lean.. 1/4 turn.


Keep doing this until when you push down on the allen wrench the car starts to die (too rich).

Your results may vary.

danglerb

If this is your mechanics problem, leave it alone and give him a chance to fix it.
If this is your problem, buy a set of CIS gauges and check over all previous work.

Put your model year info and a rough idea of location in your .sig and avatar thing.

linderpat

model year is there, geography irrelevant.

danglerb

Maybe if you don't want any local help, have no local special conditions, and it happens to be a model basically the same US and Row.

James Bailey

Given that the CIS injection has no pulse I too am somewhat stumped. But it sounds like the control pressure is way off... The allen screw adjustment on the airflow arm is for minor adjustments . You really need the two fuel pressure gauges to find out what is going on.

928toy

Many thanks for the replies!
Mech did use a proper set of CIS gauges for setting it up. Not sure why altering the adjuster screw for the fuel dist. is not making a difference (as medipedicman mentioned) - it used to. and was when it was put on the trailer). Every time the car is started it does something different. Fuel was low and the front of the car only was jacked up to change the starter - wondering if my p/u screen in the tank has sucked up some crap (going to drop the tank again and check it out, along with the fuel pumps while we're at it)
Also forgot to mention that the coil, ECU box and ignition distributor where also removed and replaced from another running car. Tried the cold start valve as well - unplugged it while the car was idling (as fast it would run was about 400 rpm) - engine stalled, leading me to believe it was running on the cold start alone, but I got back in and it started without the injector even plugged in, so I hooked it back up and no difference. Have been reading posts on RL for a year now and am getting more stumped (and frustrated) as the time wears on. Car has only seen the pavement three times in 10 years!
Just as a note, I am located in south eastern Ontario (Canada). Am considering sending the entire CIS unit (K-Jetronic & fuel distributor unit out for proper bench testing/re-build) while the tank is out of the car) since it seems from everyone's comments this is a fuel supply or over supply issue. Anyone recommend a reputable tester/rebuilder?
Thanks again, and everyone enjoy the New Year!!

vze2jshn

Who "rebuilt" your WUR. Have mechanic start over with gauges.

Fogey1

ECU? Engine Control Unit? As in computer? Not on your car, I don't think.

Maybe an ignition component of some sort, but if you have spark your problem is likely within the fuel system.

CIS/K-Jet fuel distributors/system get very wonky when they sit for a long time. Google search for CIS and K-Jet is your friend.

Good luck.

medipedicman

http://www.928classics.com/cis-service-and-parts.html

Jim Doerr offers rebuild service. Very reputable, solid resource

Jadz928

Thanks for the referral, Brian!

928toy

IT LIVES !
Turns out to be human error (of course). Initial problem turned out being that the female plug-in for the green wire had lost it's clip thus the trailer ride loosened it enough to bugger things up. The other issue ended up being that I had not fully tightened the bolt for the ground strap off the starter (as it has to get replaced after starting to make terrible noises trying to get the thing going till the green wire issue was discovered). Mech jumped in today and it started right off - even being cold as the heat had not been on in the shop. Runs amazing. Was ready to take it for a short drive up the road for the first time - and it started snowing while I was draining the old oil out of the engine. Damn. Now it is definitely going into storage for the next few months.
Hope everyone else out there gets their beasts problems solved over the winter as well. I'm sure more issues will arise when I finally hit the asphalt.