Long time issue

[Baddog]

So I have been playing with engines on my 96 Legacy L for quite some time. Some of you know, some of you don't. I have been having weird issue that I cannot seem to figure out.

To start off. I had a 12:1 compression EJ25D/22E combo with delta cams. This motor ran like a top for 8k miles. Yes 8k. Motor was un-tuned on 92 octane. It was an experiment. Ran great till the day I blew a hole in the #4 piston.

I then built a standard frankenmotor. You know the one with stock EJ25D pistons and cammed Ej22E heads. Stock head gasket size on both of these motors. This motor ran great until about 15k miles. Then it started to burn oil and all that jazz. Also started to idle really rough.

I had scored the cylinder walls on the last motor when installing the pistons so I figured that would eventually happen.

Decided it was time to build another short block. So I built an EJ251 with ACL race bearings and NPR piston rings. Cylinder walls are great on this motor. Short block is solid.

Got this motor put together and used an STi HG when doing this motor. Same heads as I started with.

I still have the same rough idle. Sporadic idle sometimes but not all the time. However always rough when warmed up. If the car has been sitting over night and I go to start it in the morning. It starts like it normally would but slowly revs up to 1.5k RPM's (cold start idle) but while it is doing this it is misfiring. Every morning this happens. About 30-45 seconds later this stops and the motor clears up.

Wondering if my issue is in the heads. Since that is all I used from the last motor.

So far what I have done.

Crankshaft Postion Sensor
Camshaft Postion Sensor
Checked timing
Replaced coil pack
NGK plug wires
New plugs
Coolant temperature sensor
Smoked tested the intake. No vacuum leaks.
Replaced the MAF with a known good working one
Replaced the IACV with a known good working one.
Replaced the ECU
Oxygen Sensors
Cleaned the fuel injectors
Replaced fuel filter
Fuel injector o-rings

Probably a few other things.

Next step I am going to do a Leak Down Test. Just here looking for more ideas because I am just about out of them. :smt021

[86bratman]

It's not uncommon for cammed frankies to have bad idle habits. But since it came on later from the sound of things it makes me wonder if you don't have a burnt valve, or a sticking injector possibly.

[Baddog]

Yeah I know it's not uncommon on the OBD1 cars. Myself as well as a couple of my buddys have cammed frankenmotors with 0 idle issues.

Injectors I was thinking about replacing

[harrymaneuvers]

Which cams are you running? Did you also couple this with a light weight flywheel? If so, I would bet dollars to donuts that is where your issue lies.

If not, are you throwing any CEL's at all?
What do you mean when you say you "cleaned your injectors"? Do you mean that you used an injector cleaning solution and ran it through the tank? I sent mine to Doctor Injector (down in Sacramento) and they replaced all replaceable parts AND flow tested them for like $21 per injector. I know there is another Doctor Injector franchise here in the Portland area.

[Baddog]

Video never seems to come out good. Anyways. Motor stalls hard when coming down from revs and sometimes just shuts off randomly. I checked my timing and it is half a tooth off on the drivers side. But if I were to adjust it at all it would be just as far off on the opposite side.

Did a leak down test and all are between 15-17%. So they are all consistent.

When all the timing marks are lined up is it normal for the intake valves to be open on cylinder 2 and the exhaust open on cylinder 4?

Got one step colder plugs and gapped them to .28 with no change.

https://sl-i.net/FORUM/images/imported/2014/01/th_20140129_171031_zpsdaucohys-2.jpg (http://i830.photobucket.com/albums/zz223/Baddog909/20140129_171031_zpsdaucohys.mp4)

[Baddog]

So I did the vacuum test. The first video is of it being semi cold (coolant gauge on the C mark). Second video is after it is warmed up @ ~750rpm idle.

https://sl-i.net/FORUM/images/imported/2014/02/th_20140201_140432_zpsqpuu0jkl-2.jpg (http://i830.photobucket.com/albums/zz223/Baddog909/20140201_140432_zpsqpuu0jkl.mp4)

https://sl-i.net/FORUM/images/imported/2014/02/th_20140201_140624_zpsnd0g7uxc-2.jpg (http://i830.photobucket.com/albums/zz223/Baddog909/20140201_140624_zpsnd0g7uxc.mp4)