My car was a block away from my house when the engine died. The dash read stability control, engine fault etc. It would not restart. Codes are p1224 - p1240 and p1241. I plugged it into a battery charger which is what I do during the winter and the next morning it started up as though nothing was wrong.

After reading these incredibly valuable forums without which I would have lost this beautiful car years ago, I removed the air filter, MAS and associated tube to the throttle body. I thoroughly cleaned the MAS, tubes and throttle body inlet (including the flappy thing inside) and removed each wiring harness and cleaned the contacts of the MAS and TB before putting it back together.

After cleaning of these systems the car ran like a top and I drove about 5 miles enjoying the super smooth ride when I got home the same thing happened again....same codes, same dash warnings.

I checked the battery which is 6 months old. 12.30 volts (no load - engine off) 14.6 with engine on.

I would welcome ideas as I am 4 hours from a questionable dealer/shop.

Thank you in advance - I will happily hit the 'Thank You" button for all replies

 

12.3 is rather low, I expect to see 12.7 or more. You might want to put the battery on charger overnight or have it load tested. It may have a bad cell.

 

Hello Brad,
First I agree with RJ about getting battery tested. It might not be you problem but the voltage is a bit low.

I had similar problems last week with my 99xk8. I first check to see if it was getting fuel. When test I found out that I had no pressure when the car wouldn't restart. Pointing to fuel dilvery problem. I was thinking it was the fuel pump but it also could of been fuel pump relay, clogged filter, or debris in fuel tank plugging the pick up. Start with simpliest and least expensive. Being I have donor/parts cars I have the spare parts to do test. I started with fuel pump relay. When I disconnected it the relay was warm. Replaced with donor relay and it has worked perfectly since. If when I tested the fuel pressure I had good pressure my next step was to swap throttle bodies. Most of the replys I got seem to point to throttle body.

I did research using jagrepair.com to see what your codes point to. He is the link.http://www.jagrepair.com/images/Auto...%201997-99.pdf

My guess would seem to be TPS or throttle body. But first if you have a fuel pressure gague check the pressure first.

 

Thank you BobRoy and RJ237!

As with so many issues with this car low voltage may be the culprit. With this huge storm we are having at the moment, that will be the best I can do today!

Otherwise I will follow your advice in starting with the fuel pressure and working toward the TB.

Thank you!

 

Yes a poor battery voltage could cause this issue so have the battery and alternator charging system checked first. If that is OK then look at cleaning the plugs to the TB. If that does not work pull the TB and send it to ASI for testing and repair.

Gus
www.jagrepair.com

 

Thank you Gus!

That is something I can do today !

 

Brad, if after doing your testing it points to throttle body I have a 97 throttle body I can loan you for a test. And if that cures it you can use it while you get yours repaired.

 

AutoZone & Advance Auto provide a free service on checking the charging system.

 

After letting the battery charger on all night, the car started with no problem, no codes. The battery at rest is 13.7 and charging is at 14.9.

I'm going to have the charging system/battery tested this morning and see what it shows.

 

Thank you for the offer BobRoy!

I am going to try to see if it the charging system/battery today. the next step would be to try that. With the battery charger on all night the car fired up perfectly. No codes, no shirt, no problem.

I will give you all an update.

 

I know that is not topical, but go to this album and check out some of the pretty nice Jags that came through my little town of Weaverville last summer. We had a nice lunch and visit. I've been meaning to post this. You can see them here. weaverville, ca Jag meet! by bradstuff | JaguarForums.com

 

OK - After being on the charger all night, the car started right up and I drove to my local big box auto parts store. They put it on the tester (in car, it's raining) and the 6 month old battery showed less than 10% available life. I happily walked out of the store with a brand new battery (no charge) Alternator tested good.

I drove home and the car ran sweet all the way home where I quickly pulled the old battery out and connected the new battery.

I did a hard reset while I was at it.

No start ugh - same codes - p1240 and p1241

Back on the battery charger.

 

Clear the codes and try it again. The codes may have been set when you got it home.

 

ok cleared the codes and tried to start but no joy. The interesting thing is that according to my Torque app, my throttle position shows at 100% and my load is a 68% which makes no sense to me. The engine is off.

 

Put your shifter in "N" and try it again.

 

Can you hear the fuel pump working? If not see if you can get a gauge on it.

 

Thank you all your help Gus.

I switched the relays out as instructed. No Joy.
I unplugged the connectors on the TB. I got 3 off- one was impossible for me to reach (driver side of the TB at the bottom)

Still no joy. I work all week (not taking it on a business trip now )

But I can't thank you enough for the time spent with me.

Fuel pressure when cranking is about 41 psi.

 

Brad,
You have fuel pressure so let's try the throttle body. I have a TB from a 98xj8. I think it is the same as the 97xk8. Maybe Gus or one our experienced members can confirm. Sent me a PM with your address and I'll send it out tomorrow.

 

I am unable to confirm that it will or will not fit. My gut says yes but not sure.

Ok when the car will not start I would like for you to test voltage at the fuse boxes under the hood.

 

Fyi

throttle body assembly fits 1998-1999 xj8 up to vin 853935 and 1997-1999 xk8 up to vin 031302