I've recently finished putting my rebuild back together and I'm so close to the finish line, but not quite there. It is a 2004 car, rotor bearing had spun was its ultimate death, and had low compression due to one apex seal being stuck down. Reused housing and couple of irons from original car, and different used rotors, e-shaft and other iron. Compression is good on front rotor and OK on rear using piston compression gauge. I've gutted the cat as it was glowing red and causing the car to die - and I had a spare. I've reset the ECU with the 20 brake stomp - although I'm sure it took a couple more than 22 before the oil needle swept. End play was fine at 0.06mm. Tried spraying intake with carb cleaner to look for vacuum leaks and couldn't find or hear any.

It struggles to start when cold, but does start. Oddly it starts right up when hot. It won't idle at all hot or cold, and if I use a bit of wood to keep the revs up it dies after 5-10 minutes - I guess this is the computer adjusting think the gas pedal is fully up. If I sit in it and alter the revs I can keep it going all day with no misfire lights, but I do get quite a few backfire pops every time I let off the gas. When I'm driving it seems to struggle with misfire lights below 4000rpm, better, but not quite right below 7000rpm, and completely fine above 7000rpm.

I guess the big clues are the better running at high rpm, and the struggling to start from cold?

I was super careful about the injector wiring, but could be one culprit. Also I wonder if it is one of the intake valves, but I haven't fully got my head round which one - or how to test them.

I'll pull the upper intake manifold off to check the injector wiring, then I'm after some assistance what valves can be tested without stripping too much off the car. I had the VDI actuator off the LIM so I could get the injectors out to test - so that may not be quite right - and I understand this opens at high rpm.

 

Injector wiring seems fine (although I check once more before putting it back!). But there is a fuel leak from my rear primary 2 injector - looks like injector to fuel rail o-ring is bad. Could this be the cause of my problem or do I need to carry on searching while fixing this fuel leak?

I checked the VDI and SSV actuator operation with a vacuum pump - both fine.

 

Oh yes, always good to fix a know problem which I might not have spotted if I hadn't been looking for rough running problems. I've sucked up as much petrol (gas ) as I can and I'm just waiting for the excess petrol to dry off before putting back together so I can check again for any more leaks.

I also think I may have mixed up the front secondary and front primary 1 - distinguishing light green and green may have got the better of me.

Feeling confident I'm getting there - thanks for your help