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Recently my EJ20G has ocasionally stuttered randomly while driving along. It just completly looses power for up to 4 seconds. I have already replaced the fuel pump, and checked that the coils were firing with a scope. Coils, plugs and leads are all fine, fuel filter is only about 18 months old. There are no codes on the computer that have anything to do with it. I've checked all the connectors and they seem ok.

What else can I try? The only other thing I can think of is to put the scope on the fuel injectors to check for loose connections.

kinda sounds like spark could be dropping out intermittently
maybe igniter module is on the way out or something liek that to do with the spark.

altho being a turbo they suffer badly if any of the fuel lines are obstructed/bent and stuff like that

and obviously there wuld be fuel in the tank

fuel regulator?

Matatak wrote:kinda sounds like spark could be dropping out intermittently

I checked the power to two of the coils and it was still pulsing properly even when it cut out. Guess I have to check the other two now.

Matatak wrote: altho being a turbo they suffer badly if any of the fuel lines are obstructed/bent and stuff like that

I think they are all ok, but I was pondering if I should blow them out with compressed air just to make sure.

Matatak wrote: and obviously there wuld be fuel in the tank

hehe yep I filled it up just to make sure!

vidler wrote:fuel regulator?

Is that the little round thing attached to one end of the fuel pump? (RX fuel pump) I've got a bosh 040? in there now but it made no difference.

surely you would try the fuel filters before replacing the fuel pump but to me it definately sounds like a fuel problem if it lasts for a short period then returns to normal, anyway try your fuel preasure your local workshop should have a preasure guage also check for contamination in the fuel! hope this helps.

tex wrote:surely you would try the fuel filters before replacing the fuel pump but to me it definately sounds like a fuel problem if it lasts for a short period then returns to normal, anyway try your fuel preasure your local workshop should have a preasure guage also check for contamination in the fuel! hope this helps.

he said his filter was only 18 months old
and i wuldnt expect a clogged fitler to act like hes sayin dropping out complettely every now and then

it is basically a 50/50 to wether its fuel or Spark but seen as uve tested the spark and its still there when its dropped power then that wuld lean towards fuel

I just tested the fuel pressure, 30psi at no load, 40 psi full load, and it doesn't vary outside of these when it splutters. If I put my foot to the floor when it's spluttering the pressure goes to 40 and it makes no difference to the splutter.

I guess I'll have to check the other two coils and all the fuel injectors now. fun.

Have you tried cleaning the AFM? they tend not to throw a code when if a little dirty and will affect running.
What other codes is the computer giving? have you tried the green test mode connectors and driven it?
Did it stutter before the 040 pump was put in?
Any particular time when it seems worse/more regular? Cruising, idleing, spirited driving?

I think I found the problem - Somewhere there is a loose/broken positive wire on the other two coils. When I was hooking up the scope I wiggled all the wires to check the connectors and the problem has now gone. I did over 100km today with the scope running beside me and it didn't play up once. I did notice a little corrosion on the copper wire going into some crimp connectors, but it was still solidly attached. On the weekend I'll pull all the wires out and solder + silicone them up.