blitzman

Suspect culprit at the moment is spark plugs, replaced with brand new NGK leads, new dizzy and rotor. Had NGK 6097 BKR7E installed gapped @ 0.030 but only cylinders 2 & 3 firing up with miss fire every now and then. Compression tested on all 4 and 270psi across the board, all 4 injectors and circuit tested.

Replaced with different used plugs from another car but not sure of the make and all 4 fired up now. So not sure what plugs to go for now!!!

Cranked car with plugs and leads out and dim/weak spark or no sparks at all some times on cylinder 1 lead and dim/weak spark on cylinder 4 lead.

2kdrift

definetly replace the plugs with new ones and report back
BKR7E are the goto plugs on a boosted setup, gapped to .028. spark plugs are considered routine maintenance I would recommend changing them at every oil change as they are cheap enough and can make a big difference.

using used spark plugs is not going to help out very much as far as diagnosing the issue. If you still have weak spark you will need to look twards, plug wires, rotor and then possibly the coil but start with the cheap/easy methods first

king06

iTrader: (1)

You replaced the distributor?

blitzman

Using stock distributor which was working fine before rebuild, only replaced the rotor and distributor cap. Ignition leads are NGK and brand new but I've dug out my old OEM ignition leads and we'll test them but car is at the local garage and I can test this until I go up there next Friday.

I will try to trouble shoot more but I've arranged to get the car into a Honda tuner who's 25 miles away from me as my engine builder doesn't seem to have the will or interest to sort this issue anymore so I'm taking the car off him end of the week.

wantboost

iTrader: (2)

Move the plugs and see if the issue follows them.

Use an infrared thermometer to measure exhaust manifold runner temperature

ohsnapzafingcu

iTrader: (2)

Or a small squirt of water will tell you approximate temp of the manifold runners.

king06

iTrader: (1)

Friends car started running rough after sitting for months. Only two runners would get hot, the other two you could touch. It ended up being a bad coil.

blitzman

So tuner changed dizzy, leads, plugs but still car misfires. Cylinder 1 & 4 always comes out with black plugs but 2&3 are clean. Tuner now says could be injectors, could bad injectors cause misfire?

dpetro1

is your firing order correct?

blitzman

Yeah we checked this even before I took the car from builder to tuner and both checked it.

2kdrift

yes.....i dont think thats the problem tho....move the injectors around and see if the problem follows them, I would actually recommend compression/ leak down at this point. once you know that is good troubleshoot the issue through injectors / spark. I highly doubt that 2 injectors are failing and only causing missfire but it is a posssibilty

blitzman

That's what the tuner will test next, the injectors but we've done compression test on all 4 cylinders and all came 270psi. I can only think that the injectors might got damaged when we tried to fit them first time, they won't fit no matter we tried and as hard as we tried and had to machine the fuel rail by 0.5mm to get them fit in with supplied O rings.

2kdrift

which injectors? on my id1000s with aem rail it was a very tight fit but a small amount of oil did the trick

blitzman

Fuel Injector Clinic 1000cc, the stock injectors went into the AEM fuel rail just fine but the Fuel Injector clinic came with 2 O-Rings for each injector and when we tried to get them in , they would not slide in.

2kdrift

Yea same story with my id1000s, oem injector fit fine. I tried Oem orings with the ID's those were even worse. Best luck was with the supplied O ring from the maufacturer, some lubrication and gently wiggling them in

blitzman

Fixed guys, it was the injectors after all. Looks like the fuel rail wasn't cleaned properly after it was machined and caused the injectors to clog. Cleaned, firing all 4 cylinders now and got initial map on Dyno done on Saturday with rev limit of 5K. Time to get the engine run in now before full dyno once I've done couple of hundred miles on the engine. Thanks all

blitzman

Ok, the misfire is back but in a different way now. All 4 cylinders are working but car has no power, feels sluggish specially on all RPM range from 1000 to 5000RPM where the rev limiter is set to and sounds like a Subaru Imprezza when driving on low RPM.

Previously cam cover was lifted because one of the bolts snapped and oil leaked into one of the spark plug wells. Replaced cam cover, replaced plugs with new NGK BRKE7-11 and cleaned the spark plugs wells. Still misfires, regapped plugs to 0.30 made it even worse, checked fuel filter and this is clean like new, spark leads are in the right order (bottom 1-2, top 3-4), test injectors by unplugging them one by one and they all are working as can feel engine tone has changed when each was disconnect.

Other observation, IVAC was loose when I checked and car was idling up and down. This has now been tightened. Other than I gave the engine bay a quick jet wash before the problem started.

Update: I thought I'd double check the IACV since that was loose before and the gasket that goes between it and the intake has gone (this probably explains the surge in idle specially on cold start up) but would could this cause misfire? I'll order replacement tonight but it will be at least 2 days before it arrives, might have the old one before the rebuild which if I find I'll try and test with it.

2kdrift

when it sounds like a WRX usually means its running on 3 cylinders in my experience

jet wash? sounds like some water got somewhere it shouldn't be... pull the cap and make sure everything is dry in there

blitzman

Do you know when idle if the engine can run on cylinders 1 & 4 only? Reason I'm asking is that I've disconnected the injectors for cylinder 1 & 4 and the engine kept running but when did the opposite and disconnected the injectors for cylinder 2 & 3 the engine stopped.

This brings me back to the original misfire where cylinder 1 & 4 weren't working and the cause was the injectors then! So I've got to try and get the injectors out and test them.

2kdrift

sounds like cyl 2 & 3 were running and 1 or 4 maybe were not running at all. I think u need at least 3 cylinders for the engine to run tho. This test does not specifically point to injectors however the cylinders in question could be misfiring for other reasons such as spark etc

blitzman

Fixed: My suspicions where right, it was the injectors or mainly the injector for cylinder 1.This is pain in the a$$ job when you've not got the right tools but I managed to pull the fuel rail with the injectors on it and disconnected the spark leads.

Cranked the engine few times and it was obvious to me that injector 1 wasn't spraying as much fuel as the other 3 injectors. On removal of the injector and closer inspection I could clearly see tiny metal shavings and some black dirt at the end of it and some more came at the back when tried cleaning it on the kitchen table.

Anyhow some 4 hours later, cleaned injectors 1 and 4 and after many tries to get this injectors back in and replacing one of the torn O rings. I fired up the car and while idle it didn't sound different but once I reved it from the TB I could tell it sounded different than before, drives nicely now and pulls really really hard all way to 5K.

I've had enough of those FIC injectors so will be looking for ID or something else, kinda shame as I only paid like $80-$100 less for the FIC instead of the ID's.

2kdrift

glad you found your issue. I loved my 525cc FIC injectors but switched to ID1000's I like both brands. they both use the same boche injector and put a specialized top hat on it if IRRC