I recently purchased a 99 XJ8L which now has 29K miles on it. The car ran flawlessly for the first several months but has recently exhibited strange behavior on start up in the
morning.

When started the MIL illuminates and message center state Traction Control Fail, Stability Control Fail, Engine in Fail Safe Mode. I pull code P1251 Throttle Motor Relay Off Malfunction or Throttle Position using AutoEnginuity.

Freeze Frame data shows: Fuel System Status B1 & B2 Open Loop, Calculated Load 75%, Coolant Temp 115 F, Engine RPM 0, Speed 0, Intake Air Temp 61 F, Air Flow Rate from MAS 52.89 lb/min, Absolute Throttle Position 7%.

This occurs on the first start of the day. The engine is restricted to about 1700 RPM. I have restarted the car up to a dozen times and let it run for 10 minutes with no change in behavior. I often smell fuel as in an over rich condition.

This does not happen every day but seems to be happening more often. The car has never failed to start later in the day and run perfectly with no warnings or errors for the duration of the day. The big cat just does not seem to like the mornings.

Can anyone offer any ideas or suggestions on making my Jag a morning cat again?

PLEASE CREATE LINE BREAKS!!

 

I suspect your battery is weak. Have it load tested or just replace. A weak battery causes many different codes on cold startup. Once the car has been running the battery charges sufficiently to get through the day.
You may have other problems, but I would start there.
And welcome to the forum. When you have time, please visit the new member area and introduce yourself. Link below:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

I said basically the same thing posted on the Jag-Lovers forum.
You can verify by monitoring the voltage drop during cranking in the morning and then later in the day to see the difference.

bob gauff

 

Thanks for the input. I did not intend to post and run but could not get logged on again to respond. My issue, to quote Ron White, "you cant fix stupid". Now I am back and wanted to provide an update in case someone was interested.

Replaced battery.... no change. Cleaned MAS and throttle body and connectors, same. Pulled cleaned and reinstalled all fuses, relays and electrical connectors involved with TPS and throttle motor relay (remember P1251 code retrieved with AutoEnginuity complete with enhanced Jag codes) and got no MIL or warning lights for the first time in 10 days. Dont know if the saga is over but the big cat did purr normally in the morning. I saw no sign of corrosion or dirt during inspection but this is a positive change. I hope it last. Thanks again for the input.

 

Thanks for coming back to post of your findings to date Bratch.

I'm thinking good thoughts for you & fingers are crossed.

Please be sure to drop by and keep us in the loop on this.

Thanks

 

With hope in my heart I insert key and twist to Key On, Engine off position. Up come the same old warnings about traction control, stability control and engine in failsafe mode. Off to the kitchen for more coffee!! Back to the car and one more quick check. All messages still in force. Off with key, open hood swap throttle motor relay for fog light relay. Both 12v, 40 amps, brown, same part number. I used a rag to ensure no transfers from me to relays of heat or whatever. Key on, no messages or codes and as expected she purrs like a kitten and the fog lights work as designed!

Am I making progress??? Dont have a clue. The car will most likely run as designed all day. I will try this again tomorrow morning to see if there is change. What a slow agonizing process.

 

turned key on and no messages or codes. One day in a row of normalcy! On top of that one son unexpectedly payed $500 on a car I sold him cheap. Thought I would never see that money again. I think I will buy a lottery ticket! We will see what tomorrow brings but there is a ray of hope.

 

Sounds like you're turning the corner bratch........thinking good thoughts for you

 

two days in a row... all is well. I believe the culprit to be the throttle motor relay. It works fine, for now, in the fog lamp relay position but will be replaced as it must be failing in some way shape or fashion to have caused so much aggravation. One more good day and there will be cause for celebration.