Relevant mods -

ID1000's
255
stock FPR
Sparktech Non CDI

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Situation is this - Been fighting with this since the end of the season, and tried to take another crack at it.

Cylinder 3# is not firing, but is getting fuel. So much in fact that after approx 5-6 mins of idle, I had almost a quart of gasoline in my oil. I suspected the injectors, so I sent them back to ID, and they checked them over and they said they were fine after being cleaned. Awesome - put them all back in, fresh plugs. Fired up right away. Idled perfect.

Went to drive it to put gas in it, didn't make it 20 yards before the misfire came about. Immediately turned around drove back parked it and pulled the fresh plugs. This is what I found. 1-2-3-4. #3 is dripping with gasoline. The rest are dry.



Only other recent changes to it are, q16 is currently in the gas tank(first and only time ever run, and before someone says something q16 is fine to us on ID1000's.)

There is currently a puddle of gasoline sitting on the number 3 piston. Running the fuel pump via evoscan didn't show any spraying in to the cylinder(if injector were stuck open). However I just realized that with the piston at the top, the valves are closed, so I will have to go repeat the test and comment back.

The only other thing I can come up with is the one coil in the COP died? I really have no clue here.

Im going to attempt to try turning the motor over so the valves in that cylinder will be open and then try the pump again to see if the injector is stuck.

 

So far at least until SparkTech gets the email - the only suggestion was to move the number 3 coil to another spot and see if the problem follows.

 

what fuel pressures, ive had injectors tested cleaned and had them fail in running conditions, if you are running higher pressures than what they test them at it may cause it to fail. if that is not an issue swap coils. they also have those testers you can hold over the coil to test for firing

 

idle it works fine -- never saw boost before the situation started.

moved coils, going to try it in the morning.

 

like i said, i believe its coils.. guess you will see in a few hours.

 

Ok sounds like you could possibly have a defective coil. I briefly looked over your work order and you purchased the system on 12/9/09 just over the typical 1yr warranty on new coils. However your fortunate because our warranty is 2yrs on these coils. You've got another Year of coverage Simply return the system and we'll test all of them and replace if necessary.

Are the plugs pictured in the correct order? Plugs 1 & 2 don't look as fresh as 3 & 4 were they all changed at the same time? It idles ok? How does it drive?

 

They were all changed at the same time, and have about 2 minutes of idling, 20 yards of driving, and the 20 yards back of the misfire ordeal.

I used an IR Therm gun to test runner temp to determine if there was any inconsistencies in combustion(hopefully they would manifest in a temperature difference). Runners 1 and 2 showed 350 degs at idle. Runner 3 was cold to the touch(60-70degs) and runner 4 showed 225 degs(indicating to me - partial burn or incomplete combustion)

I have swapped coils 1 and 3 and am going to retry and see if the problem moves from cylinder 3, to cylinder 1.


When the problem isnt there -- idles fine. Does not drive -- drives down worse then one cylinder. And when it idles with the problem acting up - it sounds like a cammed 700 horse subi

 

Testing it in a closed garage is nearly impossible to let it idle for long.

But after about 20 seconds of idling with the coils switched - the problem persisted the whole time.


Temps were 135-135-75-175

I have NO ****ing clue what the hell else could be causing this. Why is number 4 the hottest?!


In the short matter of seconds it was running it managed to fill the entire garage with noxious gasoline smelling fumes.

 

Just like you swapped the coil try switching the injectotrs and see what happens.

-Em

 

The injectors are new(fresh). They were sent to ID to be tested, cleaned, flowed and were returned.

The likely hood of the same #3 injector going there, being tested, passing, coming back, and ending up back in the exact same cylinder - is astronomical haha.

 

Going to try swapping the injector from 3 to 1, and see if that fixes it.. anyone else got any ideas?

 

As astronomical as it sounds, its odds are only 1 in 4 that its back in the #3 cylinder. Considering the issue happened, injectors were sent in, sent back, and its the same cylinder, youre safe to say its unlikely the cause. From a mechanical standpoint, its the quick and easy way to eliminate the possibility.

You say it idles fine? It may be worth running a compression test. Once you've ruled out mechanical issue, spark plug, injector, and coil, then you need to look further down the line towards the ecu.

Ive chased several coil issues on GM's 4.2L engines where one cylinder misfired all day on the scanner, switched the coild and it didnt change, and ended up relpacing the coild next to that cylinder and it fixed the problem. Food for thought.

 

yep hes in the process of testing a oem coil system to see if its a short in the sparktech system.. like you said one bad coil can make others screw up.

 

Im not even sure I got the same injectors back. But A switch of the injector did nothing.

Next is a set of stock coils if i can find a set to borrow.

 

Just tried a stock set of coils.


Fired right up, rev'd and idled perfectly. Zero signs of misfire or any problems.

Looks like COP has a problem


I will be contacting sparktech to send it back for warranty work.