Thought it was my stepper motor but...
Discussion
....now not so sure.
I've had tickover problems with my Chim since I got it a few months ago. It started off by just stalling if left ticking over for more than about 20 seconds and mild shunting. Then it got worse. Revs all over the place, toe and heeling coming up to lights etc but even then the revs would vary wildly with no change in throttle input. Basically, undriveable. I checked the stepper and it was perfectly clean. I did notice it wasn't done up tightly at all, it could easily be turned by hand. I would say it was actually slack. Put it back in with some PTFE and nipped it up and it was a different car. The car was transformed and a pleasure to drive. How I always imagined it would be.
Today, we are back to square one. In fact the problem is even worse as there is very bad misfiring higher up the rev range.
If it is a stepper motor bad connection or something then surely it wouldn't affect higher up in the rev range. And where would the non-stepper end of the stepper loom be in order to check the contacts? On the ECU?
Anything else I could easily check? I could do with sorting it myself rather than taking it to someone who know what they are doing as money is tight.
Ideas would be great.
Pete
I've had tickover problems with my Chim since I got it a few months ago. It started off by just stalling if left ticking over for more than about 20 seconds and mild shunting. Then it got worse. Revs all over the place, toe and heeling coming up to lights etc but even then the revs would vary wildly with no change in throttle input. Basically, undriveable. I checked the stepper and it was perfectly clean. I did notice it wasn't done up tightly at all, it could easily be turned by hand. I would say it was actually slack. Put it back in with some PTFE and nipped it up and it was a different car. The car was transformed and a pleasure to drive. How I always imagined it would be.
Today, we are back to square one. In fact the problem is even worse as there is very bad misfiring higher up the rev range.
If it is a stepper motor bad connection or something then surely it wouldn't affect higher up in the rev range. And where would the non-stepper end of the stepper loom be in order to check the contacts? On the ECU?
Anything else I could easily check? I could do with sorting it myself rather than taking it to someone who know what they are doing as money is tight.
Ideas would be great.
Pete
"very bad misfiring higher up the rev range"
Every time? Enough to stop you accelerating? Getting worse?
Is the car at all sluggish to start?
Reminds me of when i had driven 50 miles after the 100 amp fuse had blown (unbeknown to me).
About 10 miles later, after the car had found it progressively harder to exceed 60, then 50, then 40, I headed for a layby and it died.
The 100 amp fuse, which is under the car directly below the alternator, had blown and so no juice was getting from the alternator to anywhere else, and the car was running entirely on battery, which of course was running out. Posted my woes on PH, within an hour I had the answer to tell the RAC man
Every time? Enough to stop you accelerating? Getting worse?
Is the car at all sluggish to start?
Reminds me of when i had driven 50 miles after the 100 amp fuse had blown (unbeknown to me).
About 10 miles later, after the car had found it progressively harder to exceed 60, then 50, then 40, I headed for a layby and it died.
The 100 amp fuse, which is under the car directly below the alternator, had blown and so no juice was getting from the alternator to anywhere else, and the car was running entirely on battery, which of course was running out. Posted my woes on PH, within an hour I had the answer to tell the RAC man
Yes it was every time I accelerated but it was only when under part throttle. If I accelerated harder then it would get up and go perfectly. I took a plug out before. Looks like we're running very rich. That was after a reasonable run, engine well up to temperature.
I've checked the air flow meter with a voltmeter and the values are fine for ignition on and idle.
It did have a new temperature sensor before I bought the car but I'm suspecting that will be worth changing, just in case...
Wow, that's a hefty fuse to burn through. What was the cause of that then?
I've checked the air flow meter with a voltmeter and the values are fine for ignition on and idle.
It did have a new temperature sensor before I bought the car but I'm suspecting that will be worth changing, just in case...
Wow, that's a hefty fuse to burn through. What was the cause of that then?
blaze_away said:
Have you tried doing a hard reset on the ECU ?
If not give it a go. Easy ways are disconnect battery or unplug ecu then reconnect.
Easier to unplug the ECU IMHO. Good idea.If not give it a go. Easy ways are disconnect battery or unplug ecu then reconnect.
Did you check all the plugs, or just that one?
One misfire is barely detectable,. especially at speed.
Two are still barely detectable at decent speed and revs, car just feels a bit less keen on hard acceleration.
But at low revs, or in town traffic, it becomes obvious because of the pops and bangs on deceleration.
I drove 120 miles to London with a trained mechanic and TVR owner in the passenger seat. I felt the car was slightly sluggish on the A1, yet he and I only properly detected the misfires (plural) when we hit London traffic. Pops and bangs were amusing the kids on the pavement, but we knew we had to get the digital thermometer out when the car had cooled. Sure enough, two dead plug extenders, my fifth and sixth failures from a new batch.
Since when we have cured a misfire on Phazed's car on the rolling road (replaced number 7 extender) and two on Chim 871's car (numbers 1 and 8 IIRC), all by replacing decent looking extenders with spares from an old set. It is also quite common for the extenders simply to pop off the plugs, so check they are all fully on.
And yes, over-fuelling would cause sooty plugs and misfires at low revs, but from your description it has happened suddenly, so component failure or disconnection would be my bet. Of course the misfiring plug would be sooty, hence my question about how many you had checked. Also any bad connection in the HT system could cause the problem.
I would recommend getting rid of plug extenders, changing temperature sender, changing spark plugs to BPR6ES, and changing rotor a quality one from here
http://www.distributordoctor.com/rotorarms.html
Also check MAF plug. I replaced mine as often I would give it a wiggle which instantly improved engine idle.
In my case I cured my rough running by doing all of the above and have never looked back since.
Also have a look at this thread
It has some good info.
http://www.pistonheads.com/gassing/topic.asp?t=154...
http://www.distributordoctor.com/rotorarms.html
Also check MAF plug. I replaced mine as often I would give it a wiggle which instantly improved engine idle.
In my case I cured my rough running by doing all of the above and have never looked back since.
Also have a look at this thread
It has some good info.
http://www.pistonheads.com/gassing/topic.asp?t=154...
They look to be the same length as the originals with the same size hole so should be a simple swap. Often found in the fuse box on top of batteries in Renaults. Only downside is you can't see when they have blown without a multimeter.
Curiously the original flat type are fitted in the fuse boxes on top of the batteries in VW Polos and the ones for the ABS crack just like the TVR ones do.
Curiously the original flat type are fitted in the fuse boxes on top of the batteries in VW Polos and the ones for the ABS crack just like the TVR ones do.
QBee said:
One problem with the flat fuse is that it can crack with age, but still give an intermittent contact, so be hard to diagnose.
When you check it, get a spanner and actually remove it, as it can look intact but fall out in two pieces.
Would it be best to just replace it once a year for the measely sum of a £1When you check it, get a spanner and actually remove it, as it can look intact but fall out in two pieces.
Englishman said:
I believe some of the better dealers treat the original variety fuse as a service item. Not sure if they change every year, but probably every two at the 12000 mile service.
Personally, once changed to the midi variety, I've never had a failure.
How do you check if the midi type has blown ?Personally, once changed to the midi variety, I've never had a failure.
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