Hello all. Thanks for taking a look. I'm mostly here to complain and argue if I needed help I would have used the search. To start, I have a 1996 xjr that has been having some problems. At this point i'm confident the original forward propulsion hamster (FPH) has been replaced with 4.0l aj16 engine to its detriment.

My issues are poor performance, poor fuel economy. Excessive fuel smell, exhaust leak, reverse is jerky/misfires, and intermittent misfire.

Things I've thrown at it: BNG coils, temp sensor, crank ps, valve cover gasket, fuel pressure regulator, thermostat, one fuel injector, champion spark plugs, fuel filter, and feces. I had to stop after I got pink eye and itchy nose.

I have an idea of whats wrong but, I need a good swift kick in the rump and some independent verification.

Thanks.

 

Throttle Position Sensor?
MAF?
Gunk build up on the throttle itself?
Don't forget, when throwing faeces at it to use only Jaguar Approved faeces otherwise it won't work.

 

You might have got the feces stuck in the EGR valve. Better check that. No more throwing... proper installation is recommended. Even if it is a crappy job.

Imagine a day when your XJR is running exactly as you want... smooth power with a little bit of blower whoosh, that swiftly kicks you in the rump and nearly puts feces on your leather seat. No additional motivation needed!!

 

I note from your introduction that the SC was discounted when you bought it, were you given a reason for that? Is it actually working?
The fumes could be exhaust manifold cracked.
To improve performance I fitted an ‘Andy bracket’. I note he has them back in stock, a very worthwhile upgrade.
The other thing that really made a difference for me was a SC pump upgrade, again, a cheap and worthwhile upgrade.

 

Cleaning the throttle body is on my list. I've wanted to clean it but I didn't want to start with out new gaskets. But not a single person in the history of jaguar xjr throttle bodies has mentioned anything about gaskets, orings, or silicone so I have no idea how to seal it after it's taken apart so if you know how it's sealed now is the chance to declare your secret with the world. Even when I do get up the nerve to clean it I just have my fried back over my toe with his truck and feel i've made the better decision.

 

I think the only reason I haven't tuched the egr before is because it's hot! And I have no idea where it's at and I'm scared to look lol. I think you're driving up the right pole though.

 

Bad cafepete no upgrades until it's sorted! There was no reason given for the missing belt. I asked the guy played dumb. The car did run well after that little bit of first maintenance I gave it, but I decided it could be better and then pulled the injectors cleaned them and replaced the one with the code. That's when it started running rough, but It doesn't run bad all the time. It's like 1 month of crap then 1 week of normal it alternates. It was fast enough to beat one of those new turbo ford focus things. He was very disappointed when I told him it's six cylinder. I think he was trying to justify it by thinking it had the v12 haha.

 

So a little more info and my thoughts on the matter.

The last thing I replaced was the thermostat and cps followed by the fuel pressure regulator. I replaced the CPS because it was taking longer to start. The last day of running was a perfect start up and idle for a bit then dying completely and would not start again. I replaced the cps it started back up normally and let it run briefly. I then immediately replaced the fuel pressure regulator. The car proceeded to run fantastic for about a day and a half before returning to bum. I really want to blame the regulator but I can't.

My thoughts are the initial problems came from a miss fire caused by coils and oil on plugs. So I replaced that. Although the prolonged over fueling clogged the catalytic converters. Then the exhaust manifold got super hot cracked causing air leaks throwing the o2 sensors so a continuation of over fueling. After the cps, regulator, and thermostat replacement it has run at a more stable condition. Although still under performing and loaded with fuel. But the one day of fantastic and the every once in a while normal fuel economy. negates everything I just said.

 

I drove an XJR/6 for years. Great experience in most respects but I called it "The Tormentor", as numerous driveability problems plagued the car. I learned that not all failures provide a consistent, expected, or traditional symptom. And separating cause and effect really twisted my brain cells at times.

Anyhow, pull the connector to the ECU and check for sign of corrosion

Cheers
DD

 

Fortunately my brain cells never get twisted! Mostly because I only have one and it's hard to twist it around its self. I'll check the ecu

 

Do you have a tool to read real time data, specifically O2 Sensor voltages (swing) and STFT. Those readings may be quite useful.

If you don't have one, a cheap (chinese fake) ELM327 interface to your phone can be had for about £10 or less. A good investment.

 

Hi Greg,

Sorry to join your thread late. I just read the entire thread and found only one mention of diagnostic trouble codes (quoted above). What was the code that prompted you to replace the fuel injector, and were/are any other codes present?

Cheers,

Don

 

My car has had, in 5 years and 85,000km, these new goodies

TPS
temp sensor
waterpump
timing chains
clutch
throttle cleaned out at least twice.
lambda sensors
replacement MAF
coils
secondhand ECU
supercharger
new throttle cable (custom made) improved max throttle opening from 55 to 96%. About 100 free bhp.
radiator (before a plastic tank failed).
lots of water hoses.
Bosch electric water inter cooler pump - very worthwhile
fuel pressure regulator- may be your problem - can let you down intermittently.
rubber gusset between MAF and rest of intake - a split here messes with the mixture. Worth checking...!
...and for fun, rorty exhaust and powerhouse supercharger drive pulley.