Car Firing On 4-5 Cylinders For A Few Min Until It Warms Up And Smell Of Fuel In Engine Oil.

[sonicz]

The past week my RB25DET has been developing a problem where for the first few seconds of being started it would not be firing on all 6 cylinders properly. Its getting to the point where it does it for 2-3 minutes after being started. Some days it works fine from cold. And some days it does it on a warm engine, but eventually clears up, and quicker if the engine is warm. It works great afterwards.

Something I've also noticed, when I pulled the dip-shit to check the oil level, the oil that came out smelled of unburnt fuel, though that could be a a separate issue as my car is going through more oil than it should so I could have broken rings in the pistons, which would cause this even if the car was working normally. Compression is fine at 155psi, and that was cranking on a weak battery.

My guess is its something like coil packs (1 year old yellowjackets), bad wiring or broken/stuck open injectors, but I thought Id ask if anyone has any more to add to it.

I will be checking the spark plugs but as usual my bet is they will be clean.

I also have a smell of fresh fuel that surrounds the car even when I just prime it on reds, so I probably need to get to the fuel rail and check injector seals. But I have no idea how to get to the bolts that are underneath the stock intake manifold to get to the injectors.

[blue_vl_t]

Your injectors need cleaning, that's my guess.

When injectors get older they get clogged up and can get stuck slightly open when you shut the car off, bleeding all of the fuel from your pressurized fuel rail into one cylinder. This causes a miss when you start the car as it's too wet for the plug. Quite often it will last longer as the plug is fouled.

[Blackkers]

Are you on the factory injectors?

[sonicz]

Your injectors need cleaning, that's my guess.

When injectors get older they get clogged up and can get stuck slightly open when you shut the car off, bleeding all of the fuel from your pressurized fuel rail into one cylinder. This causes a miss when you start the car as it's too wet for the plug. Quite often it will last longer as the plug is fouled.

Makes sense. Will replace fuel filter soon and run injector cleaner first to see if it makes a difference.

Yes Blackers, they are factory injectors.

I got spare injectors off ebay in case I need to replace mine, but they came in a lot worse condition than I expected. They are of an R33 RB25DET and I believe they are 370cc ones, though I don't know what year they are off.

Can anyone tell me if the plastic claw on the end is necessary so I don't make a new thread about it? As most of them are broken on the ones I bought. If they dont do anything I will rip the rest off just to even it out.

Edited March 2, 2014 by sonicz

[Badgaz]

those are pintle caps. I'd get them cleaned and flow tested before using those....most places that service those will replace the pintle caps and filters as part of the service.

[MrStabby]

Might be worth throwing some plugs at it (and seeing what the current ones look like) since that's cheap if you're using coppers, but yeah agree with injector cleaning (and oil change!).

[sonicz]

Ok. Swapped the coil packs around and swapped the spark plugs around. Problem Stayed in cylinder #6 near the firewall. So looks like that injector is stuffed, but I will replace all 6.

Can I get someone to confirm that the injectors are compatible between 1993 R33 GTS-T throught to 1998 R33 GTS-T? I have no idea what year RB25DET year the injectors pictured above came out of. I have heard the injectors of the series 1 and series 2 are different. Is this true? Would either year fit in my stock 1993 fuel rail? I dont want to have to open it up to find they dont fit.

And can anyone tell me what O rings I need for the pictured above injectors, preferably E85 compatible.

Edited March 9, 2014 by sonicz