Bruno'S2

Hi,
Did an engine out reseal over the winter, changed the clutch while at it now everything is back together and cylinder 2 injector is injecting fuel constantly instead of in sequence. Engine starts but burbles and shakes plus fuel is coming out of the exhaust manifold. First suspected the injector, had it tested and I was told it was finished so I replaced it with a new one. Tried switching it with another one with the same results. Add other 3 rebuilt, no change. There is fire, compression is good. In one of the trials, the plastic cap on the tip of the injector came apart and fell in the head. Had to retrieve it and the seal from the injector hole but succeeded. Don't know where to go from here to resolve this injector problem or is it an injector problem?

konakat

There isn't really a sequence. All the injectors fire every spin of the camshaft, they are all controlled by the same signal. I don't really see how it is even possible for one injector to fire differently than the others unless the injector itself is at fault. Any short in the wire would affect all the other injectors as well.

Dougs951S

What he said, the injectors are batch fired so you have an injector that's hung open. Don't run the car anymore till you replace it.


Edit: Wait, just to be sure...what you are saying really doesnt make sense. if you replaced the injectors..it probably isnt the injectors. How do you know one injector is constantly firing? Have you tried cranking the car with the injector rail out of the head and spraying into something like a bucket or even the open air? (not a good idea btw, but is a telling test)

Bruno'S2

Yes, the car was cranked with the injector rail out and there is a lot more fuel coming out of number 2 has if it's spraying constantly.

Sysgen

Salut Bruno,

The injectors fire when the signal to that specific injector is grounded, could it be that the wire is touching anywhere? Has to be that.

konakat

The only way a single injector could have a problem like that would be if the ground wire to just that injector was broken and then the disconnected ground wire got grounded. Not impossible, but highly unlikely.

Sysgen

An unsheilded wire to that injector touching metal would do that, no? It doesn't need to be broken, just exposed and touching something.

konakat

All the injectors are wired together. If one was grounded, all would be grounded.

Sysgen

I've identified the lines for injector #2, red is the ground to the DME, and blue is 12volts, right? I don't know how this translates into actual wires in the harness but there is a small section where they could be cut and making ground. I also notice they fire in two banks, 1-2 then 3-4 together.

Sysgen

Bruno, just spoke with Simon and he is of the same opinion, if you've swapped the bad injector for a good one and the problem remains, and since injector 1 and 2 fire at the same time using the same wire, it has to be a wire in the harness that is keeping the injector #2 to ground. I just don't know where the grounds for injector 1 and 2 meet in the harness.

You could check that also with a Scope, I have a small one if that can help.

Bruno'S2

Thanks guys. I will start digging into this.

Bruno'S2

I'm throwing in the towel. Can't find any electrical problems or grounded wires. I'm looking for recommendations on where I can send the car in the Montréal area to get it back on the road. Any suggestions?

V2Rocket

have you tried another DME?

Van

Is Markus Blazak in the Montreal area?

Sysgen

Ron Green?