98 XJR Engine Sputtering
#1
02-16-2010, 08:46 PM
Guest
Posts: n/a
98 XJR Engine Sputtering
Upon driving my car for about 5-10 minutes, the engine sputters and the entire car shakes. However, if I shut off the engine and let it cool off, the sputtering stops only to return when after 5-10 mins of driving.
The sputtering also does not occur when car is idle.
Any idea what may cause this?
Vacuum, sensor? I am assuming this only happens when the engine is warm.
Thanks.
The sputtering also does not occur when car is idle.
Any idea what may cause this?
Vacuum, sensor? I am assuming this only happens when the engine is warm.
Thanks.
#3
02-16-2010, 09:01 PM
Veteran Member
First thought is throttle body. There was a Service Action on this vintage car that provided replacement or ECM reflash. See post #2 here: https://www.jaguarforums.com/forum/s...ad.php?t=25334
There was also a TSB on throttle body connectors causing intermittent issues that involved replacing the electrical connectors.
There was also a TSB on throttle body connectors causing intermittent issues that involved replacing the electrical connectors.
#4
02-20-2010, 09:27 PM
could be a boost leak,happens whens its warm,if you shut off and restart does it have a long crank ? it could be just a throttle
the supercharged cars have 2 fuel pumps it starts with the 2nd pump and transfers to the primary when started,the 2nd fuel pump come on at boost aprox at 3k rpm,hook up a fuel gauge and see what your fuel psi is???
keep us posted
the supercharged cars have 2 fuel pumps it starts with the 2nd pump and transfers to the primary when started,the 2nd fuel pump come on at boost aprox at 3k rpm,hook up a fuel gauge and see what your fuel psi is???
keep us posted
#5
02-21-2010, 01:20 AM
Veteran Member
How does the car drive in the first 5 - 10 minutes? Is it close to as how it should? Do you have all the power?
The difference with a cold engine and warm one, is that when cold, the ECU is running in open loop. That means it will not manage the engine based on the O2 sensors, but mainly on the MAF input.
So it could be that the the ECU is thinking the mixutre is not right (eventhough it is) and will adjust it wrongly. My first guess would be the O2 sensors themselves, but would only judge this by measuring some sensors of the car.
The difference with a cold engine and warm one, is that when cold, the ECU is running in open loop. That means it will not manage the engine based on the O2 sensors, but mainly on the MAF input.
So it could be that the the ECU is thinking the mixutre is not right (eventhough it is) and will adjust it wrongly. My first guess would be the O2 sensors themselves, but would only judge this by measuring some sensors of the car.
Thread
Thread Starter
Forum
Replies
Last Post
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)