Well, While my car has been down (My FD) I started tearing into things that needed to be done.



I got to the spark plugs and this is the second time that I have changed them (since the new motor, 10,000 miles on new motor) and noticed the same thing. My front rotors plugs were fouled very bad. Rears were as expected, not fouled.



I then checked spark and from what I can tell all the plugs fire and have the same amount of spark. Nice blue one dancing around. I did this with new plugs, my current/old plug wires and grounded them out to the chassis while I sat inside and cranked the motor. So I don't think its my plugs, wires and coils. I think those are all ok from what I can tell and just did.



I replaced my primary injectors (550s) with new ones when the motor went in. Although my old modified 850's to 1300s were not replaced and have about 20,000 miles on them. And I did not have them flow tested or serviced, my mistake.



So I guess the question is, What can cause one rotor to foul plugs and the other one not?





I've searched a bit and found that one of my injectors (front rotors) could be leaking causing an overly rich mixture in the front rotor. So I thinking maybe my 1300s need replacing. I'll pulll then and send them out for service to be sure.



As I was searching I found some threads that stated the oil control rings could be going out and this would casue larger then normal amounts of oil into that rotor.



I also have a touch of oil leaking from somewhere near my oil metering bolts so while I'm getting the injectors looked at I'll track down the leak.



Another question is, could the OMP be causing this in some way shape or form?



This weekend I'm going to do some carbon cleaning to the motor (because I run a touch rich and didn't have a wastegate on for some time, so no boost and no hard driving to clean things out) and run a compression test. When I parked it it flooded so I'm also over coming that at the moment before I run a compression test.



Let me know what you guys think,

Thanks for your time,

Joe

The last time I checked compression was about 5000 miles ago and I saw three even pulses around 110 on the front and rear. So I hoping I see the same thing when I check it again this weekend after the deflooding and carbon cleaning.

the injectors would have been my first guess. yet if the omp if pushing and uneven flow to the front that might foul them also. me, i run my omp full boat and pre-mix. i clean my plugs every 2 weeks just for that reason. but i got plenty oil.

If the omp was having a problem that was related, id suspect youd be having a smoking (blue) problem as well. As for the OMP leaking... they allways leak. But when you replaced the motor I dont know if you replaced the o-ring inbetween the front cover and the OMP or not.



They get VERY brittle over time, and can feel as hard as the metal they are put on. If you havent replaced the o-ring allready Id suggest doing so. Also if you HAVE replaced the oring, its very easy for the oring to get pinched during installation. Id check the oring out if thats the case



My money is on the injectors. Get those injectors checked out, and see what happens.



Keep in mind on the FD also that the runners going to the rear rotor are shorter than the ones going to the front rotor. (problem mainly for USDM cars) However I doubt this is enough to make one set of plugs foul and the other not in just a few thousand miles

if the car isnt showing signs of extra oil in there ( blue smoke) then yeah like horn bm id bet one of the injectors is haywire, maybe ones gettin stuck open or something??

i have come accross this problem several times.... and it ended up to be a combination of a couple of things.



one was dirty front rotor injectors (which you have ruled out)

another reason was because my car was tuned via air fuel ratios..... the total a/f was 10.8 so the rear rotor was running rich and the front was running lean, but combined it was 10.8 a/f.



next problem in my equation was a bad ignition wire in the rear rotor, as the new plugs were put in, the car would run great, and as i drove the car the spark that was not intense caused richer conditions.



in other words... my suggestion is for you to check your ignition wires for any tears any greenish residue inside the coils and the leads for the wires. lastly, make sure you use new plugs.



good luck

No blue smoke really, I'm just very rich. So I don't really think its an oil problem either. I was just adding information and some history.



I'll have to ask Mike if he replaced that o-ring inbetween the front cover and the OMP. I believe he did, we replaced all the seals/gaskets/o-rings. But it is not leaking from there. I have small amounts of oil at the top of the motor by the OMP bolts. So I'll track that down and replace the crush washers probably. It could be the OMP lines which I'll look at.



Yes my car is tuned off of AFRs only also and I dip into the 10.8 range under boost also and 12.0 at idle. So very rich. This was one thing I was going to tackle but the I ran into the fouled plugs in the front. I need to hook up my vacuum line to my FPR and lower the base pressure. Then watch for the rising rate and go for a re-tune.



So I'll pick up new plug wires and test my coils. I guess I'm hoping my front secondary injector is the problem.



Everyone, Thanks for your time and input.

Joe