Hey Everybody, thanks for reading this hopefully you don't get too annoyed with me. I've been searching the archives and I think I'm just getting more confused of where to start with this.
I have an 89 xjs thats been sitting for awhile and I'm trying to bring it back to life. The car will start and idle kinda rough, however I don't think the passenger side of the engine is running. The reason I think this is because:
1. when the car is running, there is no air being drawn into the passenger intake.
2. The passenger exhaust has a steady stream of exhaust coming out that is not being broken up by cylinder firing.

I took apart the distributor and although it is not a marelli, everything looked good and new. I also pulled one of the plug wires, attached a plug to the end and was getting real good spark.

Now my mechanical knowledge says that I have a cylinder head problem, but I'm hoping maybe it's a sensor or something else.

Thanks in advance for any direction I can get...

Or if anybody is in north east pa and wants to make a few bucks to come and give me a hand, I'd be open to the help!

Thanks again

 

theres no way that your engine isnt pumping air through the intake. if its turning, its drawing air. check all your plugs for fire on that bank, and check all of your injectors for pulse on that bank.

 

I agree with you, What I can tell you is that I can hold my hand over the right side intake and there is no suction. Now, when I take the filter cover off, there is a ton of air being pumped in through the breather, that must be where it's pulling it's air from.

I will check spark on all wires and check the injector pulse and report back.

Thanks for the advice.

 

check the rear of the breather and the throttle body. open the breather up and see if the engine starts running better.

 

Is the air HOT remember this a 6 cylinder (on each side) so the exhaust will be smooth with no pulsing.

How do you know it is not a Marelli? How big is the distributor?

 

yes the exhaust is hot.

I was working on it this morning, going on the advice of m90power. I got under the car and noticed that it is true dual exhaust front to back. So m90power and you are correct in that there is air being drawn in and exhuasted.

I am totally new to jags and v12's. I guess what is throwing me off is that the drivers side is really drawing air in strong and pulsating from the exhaust, while the passenger side is hardley drawing any air at all and the exhaust gas is very smooth.

I'm still going to get some noid lights today and check the injector pulse.

I do think it is a marelli ignition, but the cap and rotor are aftermarket.

 

As far as *that* particular aspect goes...it's perfectly normal on the V12 so you can out it put of your mind

Cheers
DD

 

im thinking its drawing in air from the other manifold via the air rail, crossover, and the bit at the rear of the breathers.

 

Thanks for the info, I had no idea that is proper behavior for this motor. We'll I guess thats it then. I'm still going to go over it and try to figure out the rough idle and hunting, but at least I know the intake it acting correctly.

 

mine was running really rough as well until a member told me to check the TPS. its an easy check. also check each injector for pulse by listening with a screwdriver or stethescope.

 

I would be looking at the side that is pulsing you more than likely have one or more cylinders not firing.

The exhaust from each side of the V12 should be a smooth flow air with No pulsing

You can identify Marelli by having 2 HT leads going into the distributor. It will also have 2 ignitors on the top radiator support and a 3 tooth reluctor wheel on the crank

 

I was just thinking can you take a video of each side of the exhaust with your hand in front of the flow so we can hear what is happening. Post it back (or a link to youtube)