Mikey93

Hi all, First off sorry for the long post.

Desperately needing some help with my V4 STI
Spec as follows,
Alcatek ECU running Mafless
550cc injectors
md321h turbo
Swirl pot set up in boot

The car was off the road for 1.5-2 years. Had quarter a tank of fuel in it. When I first brought it out of the garage it was running rough as expected but managed to get it to the petrol station and pretty much filled the tank with 99 ron. Drove it a few miles which seemed to clear up the rough running then parked it up for a few days.

Now when I start it the car idles shoot straight to near enough 2K and misfires fairly badly. Drivable but barley and clearly over fueling. If I remove the plugs they are wet and is the same for all cylinders.

Things I've checked so far...
New plugs and leads, changed for coil for a spare - No difference.
Injectors removed cleaned with carb cleaner and pulsed with injector tester. All seem ok to me.
Fuel pressure steady 40ish PSI
Voltage of TPS 0.5v at the ECU
Voltage of coolant temp drops to under a volt when warm.
O2 sensor reads between 0.1 and 1 volt
ICV removed and cleaned although I think it was fairly new. Checked resistance but I dont have a scope.
Checked map sensor with a vacuum pump and voltage changes.
Intake air temp sensor voltage changes but I have no idea what it should be as it's an alcatek one.

Would greatly appreciate any advice as I'm tearing my hair out. Does anyone with knowledge of Alcatek know If I can somehow read fault codes.
I have had the battery unplugged and various sensors disconnected, Does anyone know if the Alcatek ECU has some sort of learning cycle if it has been unplugged for a while. Do you think it could be the old fuel?

Any advice greatly appreciated

Cheers
Mike

1509joe

iTrader: (2)

Possibly injector O rings.

Mikey93

I've had the injectors out and put them back in with a dod of vaseline. Would I not see evidence on this on a fuel pressure gauge? If I prime the pump the pressure in the rail stays solid for a while. Is there any other way to check? Thanks for the reply

1509joe

iTrader: (2)

Well if that's the case there probably ok.
You'll have fun with Alcatek unless you've the dongle and lead.

Mikey93

Tell me about it🤦 think there still is a chance it could be the seals? Is it worth taking the manifold off to check 100%. You wouldn't happen to know if there's any way to reset the alcatek? Thanks again

1509joe

iTrader: (2)

You don't need manifold off just undo the rails and you'll get enough to see.

Mikey93

Getting somewhere... Makes no difference to the running if injector 1 is unplugged. Checked with a test light and seems to be pulsing rapidly! I'll whip the plug and injector out and see what I find! Best way to clear an injector anyone?

Mikey93

Also can anyone tell me how I would go about checking the ignitor?

Mikey93

Varying good news... checked for spark on all cylinders (again) and all look spot on no difference for either head so I'm reckoning igniter and ignition side are all good. Changed no 1 injector for a v5 one I had lying about. Had to make a small loom but fired up and is idling far better.

I've hooked the injector up to try and clean it out but this is where things get strange... Has anyone ever came across an injector that will shut it's self off under pressure? I'm using an injector tester which pulses and a can of contact cleaner as all out of carb cleaner. I can pulse the injector and spray into it but as soon as I block the other holes to build up a bit of pressure the injector shuts off. We can't be talking more than 10psi out of a half empty rattle can.

Any thoughts would be great before I order another set of injectors👍

Mikey93

1509joe

iTrader: (2)

Take them all out and get them professionally cleaned and then if that's not a success get some new ones the old fuel lying in them must of gummed them up..

Mikey93

My thoughts exactly👍one other thing.. would bad injectors cause the high idle or do you think it maybe another problem?

Mikey93

Right folks, stumped with this🤦 I've swapped cyl1 and cyl2 injector and the problem stays with the cylinder. Definitely getting fuel and spark on cylinder 1 and it has the best compression of all the cylinders. Any advice what to look at next? If I unplug the cam sensor the engine still runs. Is this the norm for alcatek? Will try and check the timing when kids are in bed. Does this sound like it may have jumped a tooth?

Mikey93

Took plugs out. 2 and 4 are fine but 1 and 3 are wet and as if it isn't firing

Mikey93

It's blatantly jumped it's timing🤦🤦 how many teeth can I get away with before it's game over for the engine?

1509joe

iTrader: (2)

Wouldn't like to speculate but have seen four and still ok. Remember the timing marks leave all pistons midway up all the bores.

Mikey93

Re timed the engine... Compression test is spot on with 130 give or take 5 across all cylinders which I think is ok for forged pistons. Starting up and running like a bag of spanners😭🤣 any suggestions? Match and lighter?

Mikey93

Update for anyone this might help...
TIming had jumped 2 teeth drivers side.
Timed back up still running like muck so went back to basics.

Engine was still flooding and oil smelled of petrol. Change oil and fuel filter. Took injectors out and cleaned them through for a second time. Took great care installing them with some vaseline. Turned engine over with plugs out fuel pump fuse pulled. Put an old set of 6 plugs in. Fired up right away and has not idled as good in my 5 years of ownership


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