Cylinder #8

[rascal]

Shortly after I bought my truck the SES light comes on (of course). So I went it got it checked which showed cylider 8 misfire. They cleared it and the light comes back after a short time later. I went out and bought the Auto Enginuity tool since I plan on having this truck for a long time and there it is again...

P0308: Cylinder 8 misfire

I ran a buzz test this morning after the truck sat all night and all injectors were signing loud and clear. So I fire it up and run a cylinder contribuition test:

P0284: Cylinder 8 Contribution/Balance fault.

Aside from all this the truck runs fine and I am getting 15 mpg which seems normal for a non chipped, stock truck. I have a new EPBS on the way and hope to see a little better mpg after that.

How big of an issue is this? Is it a ticking time bomb that could explode at any moment? Anyone here have any experience with this?

Thanks

[rascal]

Anybody? Ok, well I have been reading a bit more and since it is #8 I am leaning aways from needing to do a compression test or thinking it is a valve issue.

Apparently the #8 is a common issue that a lot of people attribute to the LL injector that is supposedly there. I have read that some people take of the valve cover and find the AD injector and not an LL.

Some people even talk about it being realted to the grey CPS issue and telling people to replace it with the black CPS. I will check my CPS tonight although I need to figure out which part of the CPS should be grey or black.

I turned off the SES and took a 12 mile trip doing 75 mph for a good bit of it and the light did not come back on but I am sure it is only a matter of time.

[rascal]

After reading a lot today the first thing I am going to try is changing my CPS.

I ordered the "improved" black IH version from dfuser tonight. They make quite a few claims about it:

If you own a 7.3L Powerstroke, you may already be aware of the shortcomings of the stock Cam Position Sensor (CPS). It is common for the CPS to fail causing the engine to run poorly or to stop running altogether and it usually happens at the most inconvenient times, such as in traffic or pulling a load so many owners carry a spare CPS.
This International Harvester CPS can be installed in the Powerstroke engine and will make the engine run quieter, smoother while increasing performance and mileage!
Provides a different signal (changes timing from standard CPS) to the Ford computer which results in a more accurate injection of fuel and better running engine with easier starts!
Works on all 94-03 7.3L Powerstroke Diesel.
Results vary by applications!
International Part Number: IHC#1876736C91

I will install it as soon as it shows up and let everyone know what effect it has if any.

I will keep the grey one (F7TZ-12K073-B) as backup. It should help me if I am in a jam but these are supposedly notorious for causing the cylinder 3 & 8 CCT failures.

Like I said, I will let everyone know what happens.

[rascal]

Got my new International CPS (dark blue) today and installed it. I immediately hooked up AE to run Cylinder Contribution test and now cylinders 3 & 8 are throwing the code! (UGH)

The CPS that was in the truck was the light grey version.

However, the truck started up quicker. I did not notice much difference in idle.

I am taking her out tonight so I am interested to see if she runs any different. I will be able to test MPG soon as I will probably fill it up tonight. I have been getting 15mpg.

[rascal]

Well I took her out for a run and call me crazy but she does seem to run better. The engine seems smoother and she just ran better.

I filled her up tonight so I will see if I get any better mileage. I got 14.1 mpg on my last 20 gallons.

However, my SES light remains. I am sure it is the #8 misfire code. I will check it before I go to bed.

Man, it really seems like I am talking to myself...

[Sticker Monster]

interesting that just last night i hooked up my ae scanner for the first time on my new to me ex. i seem to have a similar situation only i don't get the ses light. from what i have read, the big difference with the "blue" cps is the supposedly stronger magnet. how much did the blue cps cost you? i was considering running some fuel system cleaner through it before buying any parts. i read somewhere about the #8 injector being different because of it's location on the rail but i don't remember the details. i will have to look into that more.

SM

[rascal]

Got my blue CPS from dfuser.com last week for $49 but I happened to look at the site today and now they are $39 for a limited time!

Never fails...

[Sticker Monster]

looks like that time has run out. they are $49 now. thanks though, i couldn't find the blue one for less than $109 this morning.

SM