sweanders

I purchased another 951 a couple of days ago and second day of ownership I chipped it along with FPR and boost controller.

After almost two hours of driving I decided to see how it did at high speed and gunned it. After a few minutes of full throttle application in fifth gear it started hesitating and I stopped by the side of the road. It had a rough idle but I couldn't spot anything obviously wrong. I limped along to a friends place and it got progressively worse. But temp was fine and as long as I kept the revs at 3500-4500 and at steady speed (no boost) it ran fine with no vibrations.

When I got to my friends place I had a chance to pull the plugs, #1 completely burned. #2 looked normal, #3+4 were white as chalk. Not knowing what kind of plugs they were I swapped them for a set of known good plugs. But there was no difference when starting the car and it still had rough idle. I had a closer look at things and found the injectors looked like they were burnt brown, instead of the stock green the looked melted/fried on the outside plastic. I have pics but won't be able to post them for another few hours.

I have a set of stock injectors ready to go in but would like to find out if the ones on the car were bad or if they gave up because of something else.

When cracking the bolt on the fuel rail there came fuel, and one of the plugs indicated that it was getting plenty of fuel.

Could it just be that I had set the boost to high and in fifth at full speed (6000 rpm+ / ~1 Bar) the injectors simply were run over their capacity and overheated? The car has AFM and a K26/6.

sweanders

Just spoke to a tech/friend and I am swapping the injectors tonight. A few symptoms indicates that the problem is limited to bad injector(s).

OriginalSterm

if you run injectors at or near 100% duty cycle for an extended period of time, the coil will fail. not sure if this is what happened, but it is a possibility.

sweanders

Ok, this is bugging me beyond belief. If you have any idea please help.

The car is running rich at idle and hesitates when it gets some gas. When driving it it acts the same.

I've replaced injectors, rotor, plug wires, plugs, rotor cap, BOV, FPR.

I've measured the ignition coil and compared to another working car and the values from Clarks Garage.

Vaccum was good and after me chasing some minor vaccum leaks it is even better.

I've cleaned the battery points and ground points.

What happened was that when I was driving along at high speed it started hesitating and it gradually got worse. Now it is stuck where as it is. What is wierd is that it sounds like all cylinders are firing but it is running rough, from the exhaust it sounds like a fishing boat. The oil smells of fuel so there is no doubt that it is not burning all fuel...

I am running out of ideas, it is running constantly rich whether driving.

JET951

have you checked your TPS? if these arnt set for idle properly they can cause strange running. and they commonly fail. which also causing strange running.

sweanders

I disconnected it and there is no difference, does this mean that it is faulty?

jyoon

get a scope and check your injectors. they should make a clicking sound. did you just change the one injector? is it possible your cat is clogged?

KuHL 951

I find the comments the "plugs were white as chalk", and then "the oil smells like fuel" after replacing the injectors very contradictory. Are you sure you didn't run super lean at WOT and do more than just toast 4 injectors and a set of plugs? I would do a compression test myself if I found 3 white plugs and 1 with the tip burnt off. If you did surpass the injectors duty cycle there's no telling how lean you were running at that speed unless you had a good WBO2 on the car. Hopefully it's just something in the DME or a plugged cat.

sweanders

I changed all 4 injectors to a known good set.

Would a clogged cat run to the car running rich?

JET951

yes possible. dont you have another 951? just start swapping a few of the easier parts. like the TPS then maybe AFM. etc. im sure that with the TPS disconnected it will stumble may even stall off idle

sweanders

I'd love to swap parts, but the cars are not in the same location.

anders44

use your multimeter and measure both

Driftomagnifico

Compression test time.

sweanders

Unfortunately my compression test gauge is in my other garage.. I have a limited set of tools where I am located.

Pulled the plugs again:

Cylinder 1: white, dry
Cylinder 2: black (healthy), wet
Cylinder 3: white, slightly wet
Cylinder 4: brown/white, slightly wet

Driftomagnifico

Pull the PCV, see if you have alot of blow-by or air coming out of it.

Cracked ring land would pressurize the crankcase on combustion.