EJ20G running rough

adamb · Post by **adamb** » Fri Feb 01, 2008 12:41 am

hi,

im having a few problems with my conversion. the engine is in the L series and i cut the wiring loom down myself.

It doesnt have an exhaust on it as of yet and i got 2 of the connectors mixed around, (air flow sensor and ignitor). i tried starting it for a while before i realised i had done this, then swapped them around and it started first click. Its the first time ive ever heard this engine run, (was a half cut from swan auto), and it runs like an absolute pig at idle.

Jumps around all over the place in terms of revs and sometimes just dies altogether. it sounds like its not running on all 4 pots but it could just be the rough idling making it sound like that. im not getting any error codes on the test mode of the ecu either. could i've stuffed the ignitor by putting the air flow sensor connector into it? I borrowed an air flow sensor off matatak to see if it was that but it still runs the same but still am unsure about the ignitor. Any help would be grately appreciated as im not sure as to what to look for.

cheers,
adam

julian · Post by **julian** » Fri Feb 01, 2008 11:04 am

Any chance this could be caused by a missing exhaust oxygen sensor?

Outback bloke · Post by **Outback bloke** » Fri Feb 01, 2008 12:49 pm

If the front cut sat for a while then the injectors will be clagged. Very common problem. I take it you put new spark plugs in before you fitted the motor? If not, do both. Injectors and plugs, then take it from there.

Outback bloke · Post by **Outback bloke** » Fri Feb 01, 2008 12:50 pm

You can find out which one it is misfiring on by unplugging a coil at a time while the motor is running and listen for engine note change.

thesaidbin · Post by **thesaidbin** » Fri Feb 01, 2008 3:13 pm

id put money on the oxy sensor not hooked up and also check the plugs & leads for corrosion

Ben · Post by **Ben** » Fri Feb 01, 2008 4:21 pm

If it's an early single turbo then the IAC (idle air control) valve will likely be toast too...

adamb · Post by **adamb** » Fri Feb 01, 2008 4:58 pm

Julian: the oxygen sensor is hooked up but im unsure as to whether it works alright, it has a small dent in the side of it.

BYB: thats probably what it is, looks like its been sitting at swans for quite a while. i changed the plugs before i put it in.

thesaidbin: the oxy sensor is hooked up, but should probably buy a new one since it has a dent in its casing

Ben: could be Ben, not sure on that one.

cheers for the help.
adam

thesaidbin · Post by **thesaidbin** » Fri Feb 01, 2008 5:17 pm

also if its a suspect afm you can run it up unpluged(it will idle fine). just dont try and revup or spool the turbo :P

Outback bloke · Post by **Outback bloke** » Fri Feb 01, 2008 5:41 pm

The idle may be slightly rough if the o2 isn't right but it won't cause a miss. I doubt you would even notice the difference. The variance that the O2 can justify fuel mixture is SFA. With out it connected they default to full rich. Sounds bad but it really isn't much at all.

adamb · Post by **adamb** » Fri Feb 01, 2008 6:26 pm

oh ok, thats another one to cross off then. i have some pretty good evidence that it could be a broken igniter, i did the unplug coil packs one at a time trick and it seems theres definitely 2 cylinders missing. my theory is that when i crossed the igniter connector and the air flow sensor over, i may have stuffed one of the transistors in the igniter, causing 2 cylinders to not get a spark. if im reading my wiring diagram correctly there looks to be 1 transistor per 2 cylinders. i also checked for voltage across the coil pack connectors and i got nothing. would anyone agree with this?

cheers,
adam

PeeJay · Post by **PeeJay** » Fri Feb 01, 2008 7:26 pm

I've unplugged my oxygen sensor before and nothing much happened. Make sure you also have no vacuum leaks, when I first got my engine running it did much the same thing until I put all the air intake bits on!

PeeJay · Post by **PeeJay** » Fri Feb 01, 2008 7:30 pm

Get a test light and connect it between the + terminal on the battery and the - terminal on the coil - it should flash off as the engine fires. Then connect it between the + terminal on the coil and the bodywork (or - on battery) and it should stay on.

98choppa · Post by **98choppa** » Sat Feb 02, 2008 1:44 am

fuel pump? it took me a while to get my h.p.pump running(my wiring) and it(ejNA) was running as you described... until fuel pressure was there....oops

SuBaRiNo · Post by **SuBaRiNo** » Sat Feb 02, 2008 11:54 am

I agree with pretty much everything above. If your doing an EJ conversion with a motor that has not been run for a while i HIGHLY recomend you...

Replace O2 Sensor, Clean MAF sensor, get all the injectors flow tested and cleaned and remove and service your Air Bypass Control valve. It should be one of these as long as you have not done something wrong with your conversion (like swapping your fuel return line in the car with the fuel evap line from the tank).

The list of things it could be is endless at this stage. But i belive you MUST do all the above things. I have been involved in a few EJ conversions and these things seam to be very common problems when the motors have been sitting. Usually it is a combination of a few of them.

Also when you get it running right expect the idle to bounce around a bit searching for it's correct setting. With the car sitting there idling i have found this can take up to about 20 minutes before it sorts itself out.

Dave

adamb · Post by **adamb** » Sat Feb 02, 2008 2:02 pm

yeh, the ignitor was buggered, one of the transistors was blown. it runs perfect on all cylinders when revved, just when its idleing it sounds like a cylinder is dropping out and the engine shakes. it must be a partially blocked injector?

cheers,
adam

Matatak · Post by **Matatak** » Sat Feb 02, 2008 2:05 pm

adamb wrote:it must be a partially blocked injector?

cheers,
adam

i wuldnt think so.

id say clean out the Throttle body first and run some upper cylinder cleaner shit into it. (Subaru stuff works ALOT better than other stuff ive tryed.

a gummed up throttle body can cause a rough idle.

adamb · Post by **adamb** » Sat Feb 02, 2008 2:30 pm

oh ok, do i spray it straight into the air intake while running? another suggestion, could i have fouled the plugs because of it running on 2 cylinders for a while?

adam

adamb · Post by **adamb** » Sat Feb 02, 2008 3:48 pm

Peejay: i just did ur test with the light across the coil wires and i got no flashes when i put it on the negative. on the ignition wire it lit up all the time. i thought the ignitor wouldve fixed it but it seems it hasnt. im really confused at this point. i wont be able to find out if its the injectors until monday when i can get them cleaned.

adam

PeeJay · Post by **PeeJay** » Sun Feb 03, 2008 7:37 pm

If the engine is firing the light should flash. The idea is that you put one end of the light on the + of the battery to supply power, and the other end of the light to the - on the coil. As the computer fires the coil it disconnects the ground which should turn off the light. But on second thoughts it may happen so fast that the light never turns on or off.

Matatak · Post by **Matatak** » Mon Feb 18, 2008 12:15 am

how goes it Adamb??

did those injectors fix it up?

im keen to get taken for a spin when shes running good