29CC, 29CD despite new plugs and coil pack

AussieXer · #1 07-31-2018, 04:29 AM

I have an annoying hesitation/faltering when I accelerate from rest or from a slow speed. When cold it is accompanied by a flashing engine light which usually goes off after flashing 3 to 8 times. Other than that the car seems to run fine. My Foxwell scanner shows two relevant codes when this occurs: "29CC/not present, DME Combustion misfires several cylinders" and "29CD/not present, DME Combustion misfires cylinder 1". These faults reoccur after I clear them. I have replaced all the plugs and today replaced the coil pack on cylinder 1 but it is still happening. My local mechanic says he thought it could be an air leak. Any suggestions would be appreciated.

wpoll · #2 07-31-2018, 06:17 AM

I see you on the 4.8iS registry, so is it safe to assume it's the 4.8iS you have the problem with?

'Cause someone's gonna ask...

wpoll · #3 07-31-2018, 06:19 AM

And because I'm not that familiar with the V8s, I'll ask... how protected is the wiring to the coils on the V8? Any chance this issue is caused by some chaffed wires on the loom(s) feeding the coils?

AussieXer · #4 07-31-2018, 07:23 AM

Thanks for the response Wayne. Yes you are right it is a 4.8is. I will check see if I can check the wiring to the coils.

AussieXer · #5 12-28-2018, 12:02 AM

Taken the car (4.8is) to a dealer and an indie. One wants more time to swap injectors and the other says it is eccentric shafts and/or intermediate levers and that the parts alone would cost about $8500. Have connected car to INPA and there are no outstanding readings for cylinder 1 although I have not checked injectors yet. Camshaft position for both banks was towards top of range (120.00) and air mass was 23.5 kg/h (max 25). Vanos readings were fairly consistent across both banks. “Adjustment angle” for 1-4 bank was 0.00 and for 1-5 bank was 2.00. Appreciate any suggestions. No sign of chaffed wiring.

AussieXer · #6 12-28-2018, 12:10 AM

When I changed the plugs I did notice that the number 1 plug was oiled and after I changed the plugs it looked like the new plug was heading the same way.

StephenVA · #7 12-28-2018, 06:58 AM

Is the #1 plug oil fouled or wet fouling by a faulty injector? A pressure test on the fuel system at rest will expose a leaking injector.
Question: Does this vehicle smoke when warming up or at an idle for more than a few secs? Does it puff oil smoke on idle to hard acceleration? Smoke after idling for 10-15 mins? The last one is valve seals....

Time to do a compression test on a few cyls to determine internal engine health. Oil splashing fouling maybe your symposium to a larger issue. Once warmed up and the oil burned off, the engine runs normal? Inserting a bore scope through the plug hole with the piston all the way down in the cyl will expose the cyl walls. Look for vertical scaring in the walls for busted rings etc. Engine ever run way too hot in the past?

If compression is good, look for valve stem seals cracking and wear. A compression test does not expose this issue only a visual will.

AussieXer · #8 01-24-2019, 01:24 AM

Looks to be oil fouled. Did a leak down test and seems ok. No sign of smoking. Did a compression test and looks ok. Used a bore scope and couldn't see anything abnormal but the picture wasn't that clear.
Postscript: Looks like I might have fixed the problem. Removed the right hand vanos solenoids and flushed them out with carby cleaner. I didn't realise the mesh filters were so fine. Very easy to block. Looked clean but looks like they weren't. Car runs a lot better and no sign of any warning lights or errors generated. There may be a slight hesitation on hard acceleration but the car is quite drivable.

AussieXer · #9 02-05-2019, 12:51 AM

I thought I would do an error check to see if 29cc and 29cd were cleared. I found that they were cleared but had been replaced by 2A63 and 2A64. I checked on these two errors and finally found out they were caused by me forgetting to connect the electrical connections to the solenoids. I connected them which cleared 2A63 and 2A64 but the original error codes(29CC and 29CD) are back again along with the misfire/faltering. Back to the drawing board. At least I now know I can improve the running of the car by disconnecting the vanos solenoids. Is this conclusive evidence that they are faulty?

AussieXer · #10 02-20-2019, 07:22 AM

Think I may have solved the problem. Replaced all 8 “o” rings on the four solenoid valves. Total cost about $20 AUD. The error messages went away and the car is running a lot better. There may be a slight hesitation but I will keep working on that.