Fired up the jag yesterday for the first time in years. Cleaned injectors, new fuel pump and fuel hose, when I first fire it up it runs really rough and rich. If I give it some throttle it doesn't want to rev, if I put it to the floor, plumes of black smoke come out the exhaust. After playing with the throttle for a little bit and returns to normal. Revs fine and sounds good (besides the loud tapping sound coming from somewhere) if I let it sit and idle, it will idle for a minute or two, then the revs drop, it stumbles for a little bit and dies. This is pretty consistent. What's are your guys' thoughts?

 

.

 

The 'could be' list is long but you have to dive in somewhere, so.....

How old is the fuel?

Assuming fresh fuel, I'd find out why it is running rich.....


XJ6 Series - EFI Rich Mixture

XJ 6 Series III 4.2 - Cold Start EFI Overfuelling


........and then clean the throttle body and make sure the throttle blade is set to the proper .002" gap.


Also, make sure the ducting from the air flow meter to the throttle body is intact

Cheers
DD

 

OK so I've jumped the thermotime switch at the water rail with a paper clip. It seems like it helped with the stumble but... Still get some grayish black smoke when at WOT. And it still dies when its idling for a bit. Ducting is in tact and tight. Vacuum leaks? Distributor? O2 sensor?

 

It's not the thermotime switch that you want to jump. It's the coolant temp sensor for the fuel injection


Cheers
DD

 

I jumped #3 connector on the coolant rail. Is that the coolant temp?

 

I assume you have found the source of the 'loud tapping noise coming from somewhere' as it could be the exhaust cam striking one of the tappet buckets that has come loose from the head.

 

I have not, it has quited down a lot. I do plan on installing tappet stakedowns but first I just wanna get this dang thing running how it should

 

OK, you're good. #3 sensor is the coolant temp sensor, yes. The thermotime switch is #1 position

Cheers
DD

 

Alright. I'll get a new temp sender. Where is the mixture screw on the AFM? Any thoughts on why it "chuffs" and dies?

 

From what you've said it sounds like yours is OK. Bypassing it didn't really make any difference, correct?



If you're face the AFM from the RH fender the adjustment is at the left top corner of the AFM, in a hole, likely covered by a plug



I'd be tempted, at this point, to replace the coil. They're known to give trouble after absorbing a bit of engine heat. Any 12v coil with about 1.0 ohm primary resistance will be OK

Cheers
DD

 

Bypassing the sensor has resolved the crappy running upon startup and having to wait for it to warm up to smooth out. Or so it seems, I'll confirm that tomorrow.

Ive heard lots of good about the pertronix dizzy and coil, I think I'll go that route once I figure out which part #s to order

Last question, maybe I took out the fuel changeover stuff do to a stuck valve and a broken button on dash. It's only drawing from the right tank. Some of the returning fuel goes into the left tank. Is there a way to fix this? I do plan on putting the changeover stuff down the road but not in the near future. Also.. The car idles at about 1100 rpms. Seems a little high yeah?

 

http://www.amazon.com/gp/product/B004OXKHZM?tag=viglink21907-20 is this the right dustributor and coil?

 

Put 0.5 miles on it today... Car has absolutely no power. Won't even break the tires loose in gravel under full throttle. Tranny is full of type f, head gasket is still good. Car has 115k miles. Air flow meter? Have a little road trip planned in 3 weeks and was wanting to take this. Might have to take the vr4 or Luv if I can't figure this out.

 

Clogged exhaust?


Cheers
DD