fishfire

I rebuilt the engine on my 1997 WRX about 5 weeks ago and have had nothing but problems since.
The engine itself seems fine but I have great difficulty starting it from cold and will sometimes cut out if I am cruising below 2000rpm. It will also be very hesitant at low rpm especially if I sudenly put my foot down.

Its not so bad when it is warm but the hesitancy and sudden cutting out do still happen. I should also mention that when I try and turn it over, after a few trys the starter motor will not respond at all, although I can hear the fuel pump whirring, I then have to wait for a minute or two before the starter motor will then turn over again
I can also hear what I can only discribe as a fizzing noise coming from behind the dash if I hold the key right round to Ign when the starter motor doesnt turn. The starter motor does not always respond instantly when I turn the key to ign.
A friend has suggested that maybe the immobalizer could be fault?

I have spoken to the auto elecs that fitted the immobalizer and they seemed doubtful that it would be the immobalizer but sujested that maybe it was a bad earth.

The only way I can discribe this problem is it feels like either the fuel supply has suddenly been turned off, or there is no spark.

Also after a bit of turning over it trys to start and I do get a slight backfire but in the engine, if that makes sence?

Spec is

Built ej20
Apexi power fc & commander
740cc injectors
20G Turbo
standard FPR
standard fuel rails
NGK PFR7G's
Magnacor HT leads
Walbro fuel pump

exhaust, filter, FMIC etc etc

I had to adjust the fueling on the ecu just to get her running, as my wideband was showing it was running very lean on the old map (Pre rebuild and 20g) Injecters were globally increased from 60% to 85% to get her running and I have had to put the idle up to 1200rpm just so it wont cut out so often!

The problem is not consistant ans there doesnt seem to be any pattern to it. One day it will be ok, the next its a pig. The only thing that is consistant is it is a pig to start every time!

Sorry its a bit random, but have tried to include all my observations.

johnnyroper

first off i would advise checking all the earths around the engine are clean and tight.
basically just go back over all the loom plugs and connections ensuring they are all tight.
have you rechecked the timing marks are all lined up?

Hol

iTrader: (1)

Ditto the earth sentiments.

I would even go so far as to stick on a few extra earthing wires to the endone black as a temporary fix to see if thet cures it.

You will know for definite then.

Also check and clean the main engine multiplag connector and the one under the battery/waterbottle.