May go to craigs list - I am done

[urdrwho]

I have not been able to do away with P304 and I am done. Thought is might be the injectors, swapped them out and it came back. New plugs, new cables (oh and BTW today while pulling one out of the coil, my hand slipped off the boot, pulled on the wire and it tire). Errrrrr!!

 

New fuel filter, new air filter, new PVC, what else??? Oh -- removed and cleaned the IAC, fitted new new gasket. Cleaned every ground wire on the damn car, cleaned the MAF (twice). Cleaned the ports in the EGR valve.

 

Seafoamed the engine.

 

It never, ever, never throws a code while cruising down the freeway - it is always at idle or low throttle. It feels like it surges a bit. At idle you can hear the misfire at the tailpipe.

 

On the freeway you would never know there is a problem.

 

Well maybe there are a few things yet before Craigs list. I need to check the timing marks and I need to check the fuel pressure. I know when I swapped the injector rails out the one rail on cyl #4 side didn't seem to have much pressure in it.

[subikid90]

What plugs and wires are you running?

[urdrwho]

Running OEM from Subaru and NGK platinum plugs. It was doing this before the wires and plugs.

 

I am thinking about the coolant temp sensor. When I first start the car in the morning it doesn't have a looping idle nor has it ever thrown a code. The car is always warmed before a P304.

 

I've never known of a bad coolant temp sensor causing a P304 but if it is sending incorrect information and leaning / or enriching too much I guess it could throw a P304. But I would think I would get P300 > P304.

 

Coil ohms out correctly. Noid light shows #4 is firing.

 

I have used propane to search for an intake leak but received no results.

 

This really stinks because my main car, my Jaguar just seized its engine and I want to make the Subbie number one. If it isn't running well I can never make it number one. The 95 Legacy Wagon engine with the 2.2 runs great. Kind of weird because we only paid $1,000 and the engine runs fine.

 

The only thing I can see is the quick movement of the vac gauge needle as it wiggles about half a bar in the 20 range.

 

 

I am at a loss. The one day I went all day and it never threw the code.

 

What plugs and wires are you running?

[spooln30]

I can almost guarantee its either a dropped valve guide or a intake manifold gasket leak. While the cars running and using a can of carb spray, spray around all of the intake runners where they go into the heads. If the engines wants to die then remove the manifold and replace the gasket. You'll have to spray a lot in all over to get the carb spray in every spot. To check the valve guides, drop down the exhaust header and look into the exhaust ports and if you see a valve guide dropped down further then the others or more then about an 1/8" sticking out the heads will need to be removed and the updated guides are needed.

I actually had both problems on my old 96 L. First the manifold gasket then 2 yrs later it dropped a guide. GL

[urdrwho]

Thanks for the thoughts about this matter.

 

I'll give the spray another chance. I've done it before, I've even used the propane around the engine, I didn't get any change but maybe I missed a spot.

 

Drop the exhaust shouldn't be too bad because this engine has only been in the car since March 2013. It was supposed to be a 50,000 mile engine that came out of a totaled car.

 

Replacing a valve guide isn't something that I would want to tackle and wonder if it is worth the expense $$$$$$$. Would a dropped valve guide only be apparent at low speed because at high speed you can't tell anything is wrong.

 

The manifold gasket I would do myself. Although there are a lot of bits to remove it is only time consuming not $ consuming.

 

Although....hm????? I only paid $1200 for the car, it has 145,000 miles on the clock, the body has only one small spot of rust, the leather is 98% perfect, I installed a new stereo head, carpet is very good --- I think I have room to pay someone to do the work and still be ahead of the game. Except for the engine the car is very good - toward excellent condition. The question is how much for a dropped valve guide?

 

I can almost guarantee its either a dropped valve guide or a intake manifold gasket leak. While the cars running and using a can of carb spray, spray around all of the intake runners where they go into the heads. If the engines wants to die then remove the manifold and replace the gasket. You'll have to spray a lot in all over to get the carb spray in every spot. To check the valve guides, drop down the exhaust header and look into the exhaust ports and if you see a valve guide dropped down further then the others or more then about an 1/8" sticking out the heads will need to be removed and the updated guides are needed.

I actually had both problems on my old 96 L. First the manifold gasket then 2 yrs later it dropped a guide. GL

[johnegg]

do a compression test on #4, you probably have a burnt valve.

not common, but not rare eithr.

often caused by not adjusting the valves on an ej25 engine, 96 - 99.

they get too tight and the exhaust valve burns up.

 

good luck.

[urdrwho]

I was just talking about that this morning. My compression quage is on a long hose that works well on an engine with deep plug wells. I'm not sure if I can get it to work in the skinny space along the side with #4 cyl. The last thing I want to do is cross thread the plug hole.

 

What I need is a cold engine that hasn't run so that the alum. threads can't be messed up taking out the spark plug and/or inserting the gauge.

 

Today I've been running about and no codes. The engine is lumpy but no codes.

 

do a compression test on #4, you probably have a burnt valve.

not common, but not rare eithr.

often caused by not adjusting the valves on an ej25 engine, 96 - 99.

they get too tight and the exhaust valve burns up.

 

good luck.