Rough Idle
#41
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If I understand correctly what you are measuring is the injector pulse timing and not the pulse duration
#42
#43
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Is your idle quality good in "D" and choppy in "P"?
Has now changed. When coming to a stop, the engine will miss, possibly just the once, and then its fine. If I stay in D, it may occur again in the next minute or so but its not very consistent. So im assuming that the underlying condition is getting worse, as I have only added andy's bracket in the meantime. Ive also ran some injector cleaner though to no avail. I may purchase a single "made in japan" coil and try it in each cylinder, to rule out a coil problem.
#44
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*Update*
Was commuting this morning, car was missing more frequently, and then there was a very short cutout at 60mph, enough to trigger the check engine light briefly, but car continued to drive until I got to my destination. When I returned to drive the car back home, started the car and the engine was stumbling then surging then stumbling etc. Put in drive and it was ok, but there were obvious hesitations and flatspots. finally about a mile down the road it cut out and wouldnt start. when it did it took all of a few seconds to cutout again, so I decided not to chance it as I was in a decent place to breakdown as it where.
Ive already ordered a new CPS as that last time I started it, there were no revs during cranking. Its at 106k miles now so if its the original CPS its definitely overdue. Anyone else think its likely to be CPS?
Was commuting this morning, car was missing more frequently, and then there was a very short cutout at 60mph, enough to trigger the check engine light briefly, but car continued to drive until I got to my destination. When I returned to drive the car back home, started the car and the engine was stumbling then surging then stumbling etc. Put in drive and it was ok, but there were obvious hesitations and flatspots. finally about a mile down the road it cut out and wouldnt start. when it did it took all of a few seconds to cutout again, so I decided not to chance it as I was in a decent place to breakdown as it where.
Ive already ordered a new CPS as that last time I started it, there were no revs during cranking. Its at 106k miles now so if its the original CPS its definitely overdue. Anyone else think its likely to be CPS?
#45
#46
#47
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New crankshaft position sensor cured the problem, these things really do fail just like that. Warning sign seemed to be very infrequent misfires when in drive, usually only noticeable when stationary. The CPS that was removed is Lucas stamped, no date but looks old and the wire/rubber is very rigid.
Did notice though that the idle occasionally dipped too low for my liking when coming to a stop, drop from ~600 to 500rpm etc, others have attributed this to low ATF fluid level. Mine was on the first mark for the hatched "hot" section so Il add another 250ml of Redline D4 and recheck. If not il look at the IACV.
Did notice though that the idle occasionally dipped too low for my liking when coming to a stop, drop from ~600 to 500rpm etc, others have attributed this to low ATF fluid level. Mine was on the first mark for the hatched "hot" section so Il add another 250ml of Redline D4 and recheck. If not il look at the IACV.
#48
#49
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How do you do this in the IDS? Do you need exhaust reading to adjust the idle? I have an iDS and have not figured out how to do this.
thanks.
thanks.
Glad that a new CPS fixed it. Many fellas have learned to have a spare one, even a used one, in the trunk.
I recently adjusted my idling using the Jaguar IDS. It now idles beautifully at 750 rpm at operation temperature. Yours is pretty low if it is just around 600 before dipping to 500.
I recently adjusted my idling using the Jaguar IDS. It now idles beautifully at 750 rpm at operation temperature. Yours is pretty low if it is just around 600 before dipping to 500.
#50
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Find "Vehicle Configuration" under the top menu, then select "Set-up and Configuration" where you will find "Throttle Pot Adaption Test" and "Oxygen Sensor Orientation Test". Suggest you do the O2 sensors test first even though you have not replaced them. Then conduct the "Throttle Pot Adaption Test", during which IDS will guide your through including warming up the engine. You will notice the engine idle speed going up and down before leveling off by itself - which will be your new idle matching the prevailing ECU, TPS, O2 sensors, etc.
#51
#52
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I got the VCM kit a few months ago from forum Moderator Cambo. See his earlier thread "Original VCM Diagnostic Interfaces" in the Classified Section. He runs a Jaguar performance centre in Australia, and has a very strong network with software specialists, auto electricians and engineers.
Last edited by Qvhk; 10-09-2017 at 06:14 AM.
#53
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#56
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Am about to get a set of used injectors, thought id look at the purge valve first. Pulled hose off at the valve side, sealed the tube with an Allen key and started engine, no measurable improvement. Its getting booked in for a scan soon, these cars are hard to diagnose without such equipment in my opinion.
#57
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The injector pulse time or duration is at it's shortest in the park position , idle , and or maybe reverse position as the ECU senses this through maybe the transmission connector or the TPS or other means say the ECU sensing from the shift gate switches by way of the TCU . Unresponsive or binding injectors is the term often used . The cleaning method I used like in the video just used straight hose with hose clamps for 2 injectors at a time with a hole drilled in the middle for the glued in red tube . The connectors on the trunk compartment lights are the same as used in the engine so they can be barrowed
Last edited by Lady Penelope; 10-28-2017 at 01:41 PM.
#58
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Little sidetrack, since I ignored the first instance but now its happened twice so..
Cruising at 70mph, had been for several minutes, trans randomly shifts down to 3rd, then 2 seconds later shifts back into 4th. I dont think it started accelerating when it changed to third, was just as if id moved the stick to 3 then back to D.
Only thing ive done recently is auto fluid swap, so could this be the redline working some crud loose in the valveblock? Also saw a suggestion that it was a bad TPS or an engine misfiring under load.
Cruising at 70mph, had been for several minutes, trans randomly shifts down to 3rd, then 2 seconds later shifts back into 4th. I dont think it started accelerating when it changed to third, was just as if id moved the stick to 3 then back to D.
Only thing ive done recently is auto fluid swap, so could this be the redline working some crud loose in the valveblock? Also saw a suggestion that it was a bad TPS or an engine misfiring under load.
#59