Blacky's Impreza RA (Updated 27-01-08)

blacky · Post by **blacky** » Mon Feb 19, 2007 7:52 am

Cheers chaps

Just an update, drove the car down to work today, 140 miles, so in total I have done about 250miles of running in, hopefully fixed an oil leak I had yesterday, but now have anotehr issue, car seems to idle very lumpy, like its hunting and will hesitate at low revs whilst accelerating, I have changed the MAF, but its nowt better, so wondering what it is :?: :?: :?

My reckoning is its electrical or some sort. plugs are new, if it were the HT leads then when under load it would hesitate, but seems fine...any ideas???

duncan · Post by **duncan** » Mon Feb 19, 2007 8:26 am

Has it been mapped yet Logan?

Sounds like it is running rich at idle or that the ignition is too advanced...

blacky · Post by **blacky** » Mon Feb 19, 2007 8:35 am

No, its not been mapped, just on the standard map, but the only difference really is the FMIC and K&N. I am running my catted downpipe at the mo to run it in, just so it keeps it sensible.

As I said, feels like a electrical issue. Going to go out at lunch and check the fault codes, as due to it being in bits maybe one has got damaged :?:

other thing wwas maybe an earth is not good, as wehn the engine was out I dod wash and power hose the engine bay tehn it has sat for a few months in the workshop :?: :?: I checked the earth from the battery to the chassis last night, cleaned it up and put it back on, and no difference.

blacky · Post by **blacky** » Mon Feb 19, 2007 8:42 am

Anotehr thing that is preplexing is that the oil pressure gauage starts to fluctuate at 4k rpm, got a little above this and it settles back down...wondering if this is anything to do with if the an erth is dodgy :?: As I am sure that the actaul pressure won't flutuate +/- 0.25 bars for like 200 rpm range then settle down :?: :?:

ian · Post by **ian** » Mon Feb 19, 2007 7:37 pm

nice work mate
so nearly bought a scoob, love the sound 8)

Pavlo · Post by **Pavlo** » Mon Feb 19, 2007 11:07 pm

Could be the K&N is having an effect on the MAF, but I would check for airleaks between MAF housing and the turbo. Could be an incorrect plumbing of breathers.

Try unplugging the maf and see how it idles.

frayz · Post by **frayz** » Tue Feb 20, 2007 5:42 am

I agree with Pavlo.. i think the K&N is causing the hunting and lumpy low end running. Id imagine the MAF scaling to be out now it has a free flowing filter attatched..

As for the gauge..

Have you checked the earth to the oil press gauge mate? Sounds to me like this is more your problem.

Do you have an earthing kit installed?

blacky · Post by **blacky** » Tue Feb 20, 2007 9:09 am

Okay, did an ECU re-set last night, code 32, which is the lambda, which would explain the okay idle from cold, but once warm it hunting. The MAF seems fine, unplugged it, engine cuts straight away. Also checked for air leaks, seems fine as far as I can tell. Cleaned the crank sensor at the weekend. so think I have covered most bases.... :?:

As for the gauge, its just plumbed in where the old oil pressure sender should go, there was no earthing wire for it, I don't have a earthing kit, but I was thinking that this was the issue and I am going to make up a kit for mine, unless anyone knows of a good kit thats not silly cash :?: :?:

Cheers for the input chaps

Pavlo · Post by **Pavlo** » Tue Feb 20, 2007 9:26 am

The "unlplug the maf and see if it stalls" test is a load of old bollox I'm afraid.

You need to run it witht he maf disconnected, and see if it trasforms it from running like a bag of shit to sort of normal. You can disconnect the lambda and it will ignore it.

blacky · Post by **blacky** » Tue Feb 20, 2007 9:57 am

Okay thanks Paul, but, without sounding like a spanner, if I disconnect the MAF and it cuts, how can I drive it with it disconnected?? Will it start with it disconnected and default to a nominal value?

Okay, I will unplug the lambda and run it this evening and see if that makes a difference to the hot idle.

I did have the MAF CEL when I checked yesterday, but once re-set it went away, so I was assuming that this was an "aged" fault from the old MAF. I will check teh codes again as well to see it anything has reappeared.

Cheers