Rough running - Advice requested
Discussion
As the weather starts to improve the Chimaera starts to play up. Can I request some support from the wealth of experience here.
The situation is that the Engine appears to be running on only half it's cylinders.
I checked the spark, all appears to be ok, changed the plugs, changed the heat shield extender things on the plugs, absolutely no effect.
Changed the temp sensor for good measure, again no effect.
Checked the temperature of each port on the exhaust manifold, five measured around 340 degrees C, one was 90 degrees and two measured around 110 degrees.
Clearly there is a problem with these three not firing correctly or not at all.
Can anyone offer some assistance, could this be the injectors ?
I am no expert but would like to be able to resolve but clearly I need some assistance here. There is a smell of petrol on start up and it's noticeable that the fuel consumption has gone through the roof.
Would appreciate some advice.
Thanks.
The situation is that the Engine appears to be running on only half it's cylinders.
I checked the spark, all appears to be ok, changed the plugs, changed the heat shield extender things on the plugs, absolutely no effect.
Changed the temp sensor for good measure, again no effect.
Checked the temperature of each port on the exhaust manifold, five measured around 340 degrees C, one was 90 degrees and two measured around 110 degrees.
Clearly there is a problem with these three not firing correctly or not at all.
Can anyone offer some assistance, could this be the injectors ?
I am no expert but would like to be able to resolve but clearly I need some assistance here. There is a smell of petrol on start up and it's noticeable that the fuel consumption has gone through the roof.
Would appreciate some advice.
Thanks.
You have the problem diagnosed correctly - you are not getting a sufficient spark at the correct time at three cylinders, so are running on 5.
You clearly have fuel getting there - there is a smell and the fuel usage has gone skywards.
Concentrate on those three.
1. Are those three leads connected to the correct distributor ports? Tell us which plugs are not firing and we can tell you where they SHOULD be connected to the distributor. A nice bright spark at the wrong time would give the symptoms you describe. Once one lead is on the wrong plug, two must be, and three could be.
2. Take each of the three plugs out in turn, one at a time. Sniff the open hole and plug for fuel. Lay the plug on top of the rocker cover, with the lead and extender still attached, and make sure the body of the plug is touching metal. Start the car and check there is a good bright spark at the plug tip. If little or no spark, first try to make sure the lead is on properly. If still little or no spark, take the extender out of the sequence and try again. Still no? Try a different plug, ideally a new one. Still no? Try a different lead, perhaps one from one of the good cylinders
3. Repeat for the second faulty cylinder
4. Repeat for the third faulty cylinder.
5. If STILL a problem, try a new distributor cap and rotor arm.
You clearly have fuel getting there - there is a smell and the fuel usage has gone skywards.
Concentrate on those three.
1. Are those three leads connected to the correct distributor ports? Tell us which plugs are not firing and we can tell you where they SHOULD be connected to the distributor. A nice bright spark at the wrong time would give the symptoms you describe. Once one lead is on the wrong plug, two must be, and three could be.
2. Take each of the three plugs out in turn, one at a time. Sniff the open hole and plug for fuel. Lay the plug on top of the rocker cover, with the lead and extender still attached, and make sure the body of the plug is touching metal. Start the car and check there is a good bright spark at the plug tip. If little or no spark, first try to make sure the lead is on properly. If still little or no spark, take the extender out of the sequence and try again. Still no? Try a different plug, ideally a new one. Still no? Try a different lead, perhaps one from one of the good cylinders
3. Repeat for the second faulty cylinder
4. Repeat for the third faulty cylinder.
5. If STILL a problem, try a new distributor cap and rotor arm.
Edited by QBee on Sunday 29th March 11:27
On the basis that 3 cylinders aren't firing its unlikely to be something that isn't common to all 3 so unliely to be the leads or plugs.
Examine the distibutor cap carefully for any signs of burning or tracking and see if the rotor arm isn't damaged/cracked so its not running concentrically.
Examine the distibutor cap carefully for any signs of burning or tracking and see if the rotor arm isn't damaged/cracked so its not running concentrically.
Tyre Tread said:
On the basis that 3 cylinders aren't firing its unlikely to be something that isn't common to all 3 so unliely to be the leads or plugs.
Examine the distibutor cap carefully for any signs of burning or tracking and see if the rotor arm isn't damaged/cracked so its not running concentrically.
^^^^^ It would be interesting to see if the 3 non firing cylinders are next to each other on the dizzy cap. Examine the distibutor cap carefully for any signs of burning or tracking and see if the rotor arm isn't damaged/cracked so its not running concentrically.
I made the mistake of removing the plugs to look for a spark whilst cranking a fuel injected engine- problem was the un ignited mixture came out through the plug hole and found a convenient spark at which point it ignited with an almighty bang. No damage apart from my pride, but its worth bearing in mind if you are dangling leads and plugs near the plug hole..
HHV8 said:
................., changed the plugs, changed the heat shield extender things on the plugs, absolutely no effect.
Changed the temp sensor for good measure, again no effect.
Checked the temperature of each port on the exhaust manifold, five measured around 340 degrees C, one was 90 degrees and two measured around 110 degrees.
Clearly there is a problem with these three not firing correctly or not at all.
.....................
Just gone back to the beginning to check. Yes, you might just have the same problem as me....trusting new parts.Changed the temp sensor for good measure, again no effect.
Checked the temperature of each port on the exhaust manifold, five measured around 340 degrees C, one was 90 degrees and two measured around 110 degrees.
Clearly there is a problem with these three not firing correctly or not at all.
.....................
My car had its 12000 service on 1st March, good TVR indie. New plugs, new extenders etc
I cured the last of the resulting misfires last week. All down to the complete new set of extenders being faulty.
My TVR guy thought my old ones were a bit shabby and so replaced them with a set from a top notch supplier before they broke and caused me a problem.....yes, really!.
Drove the car home, seemed ok, then realised that I had a misfire. Had a free morning, so decided to see if I could find it myself. TVR guy said he thought I might have a slightly faulty no 6 injector, so i started by taking the numbers 2,4,6 and 8 plugs out to see if any of them showed obvious signs of a problem. Nothing, so i put them back.
Started on the other side, immediately noticed that the no5 extender came away from the plug with no effort. Looked inside it, all the others were shiny brass, this one was blackened. Tried it on a different plug, still loose. The clip inside the extender was faulty. Parts supplier sent a replacement, I fitted it, job a goddun.
Got to a sprint day the following week, blow me, I had a misfire. Phazed helped me to test things, but we couldn't track it down. 4 seconds off the pace, well pissed off.
Following day I rang Rob (V8D) to see what make/model of injectors he had fitted. He told me, but said it didn't sound liken that was the problem. Drove over to Rob, he diagnosed.....no 2 extender was electrically dead. Spark aplenty without the extender, none with. Rob replaced it for me, problem solved. Or so I thought. Went to see the TVR guy to have some new dampers fitted, and he immediately noticed that the spare extender supplied by Rob (FOC from his bits box) was actually tracking and causing.....yes, you got it - a misfire.
So just because you have three cylinders down, don't just assume that the brand new extenders are fine - mine weren't. And they weren't cheap chinese imports either - Beru, made in Germany.
Thanks for all the help, Dissy cap and rotor arm look to be ok but have ordered new just in case. Taking your point about faulty new parts.
Certainly the plug extenders do not seem to fit as well as the old ones, in fact a couple seem very loose compared with the old ones. I put that down to the old ones being on for some time and virtually welded on...
I will check that they all are working correctly as I was just assuming that new parts would be ok.
It's Easter weekend and the sun is out but I am still in the pits.......arh !!!
Thanks guys
Certainly the plug extenders do not seem to fit as well as the old ones, in fact a couple seem very loose compared with the old ones. I put that down to the old ones being on for some time and virtually welded on...
I will check that they all are working correctly as I was just assuming that new parts would be ok.
It's Easter weekend and the sun is out but I am still in the pits.......arh !!!
Thanks guys
Update......don't laugh!
The parts supplier sent me a replacement for the second faulty one. They have been very good, so I won't name them as they don't make the parts.
Fitted the new extender this morning and found that it didn't clip onto the plug - another faulty loose one. So now three faulty out of nine!!! Yes, I did try it on a spare plug - same result, if you turn it extender downwards, the extender drops off......
The parts supplier sent me a replacement for the second faulty one. They have been very good, so I won't name them as they don't make the parts.
Fitted the new extender this morning and found that it didn't clip onto the plug - another faulty loose one. So now three faulty out of nine!!! Yes, I did try it on a spare plug - same result, if you turn it extender downwards, the extender drops off......
Up date on the situation, replaced dizzy cap, rotor arm, new plugs. Leads all ok, changed coil but still not firing on two cylinders on left side(drivers side) anyone one got any ideas where we go from here?
Checked spark all looks ok.
I am at the end of my limited knowledge, I need your help.
I think I will need to get it to a TVR specialist and get a diagnostic check, where is a good place to take it in Berkshire / Surrey / Hampshire area.
I am desperate to get sorted this good weather will not hold for ever.
Any help would be appreciated.
Thanks
Checked spark all looks ok.
I am at the end of my limited knowledge, I need your help.
I think I will need to get it to a TVR specialist and get a diagnostic check, where is a good place to take it in Berkshire / Surrey / Hampshire area.
I am desperate to get sorted this good weather will not hold for ever.
Any help would be appreciated.
Thanks
For specialist help try any of these guys
Calvin at Wilton-Morgan in Hurst near Wokingham http://www.wiltonmorgan.co.uk/#/
Jamie at TVR101 in Bentley http://www.tvr101.co.uk/
David Batty at the garage in Godalming http://www.davidbattythegarage.com/
Calvin at Wilton-Morgan in Hurst near Wokingham http://www.wiltonmorgan.co.uk/#/
Jamie at TVR101 in Bentley http://www.tvr101.co.uk/
David Batty at the garage in Godalming http://www.davidbattythegarage.com/
gavgavgav said:
Take all the extenders off and directly connect the leads to the plugs, start it up and see if it runs fine. This will rule out the extenders. It takes a little while to get hot enough to melt the leads so don't leave it running/ testing too long just incase.
^ Thats what I'd try next too. I found with the latest batch of Beru extenders that the metal shroud wasn't quite big enough to fit over the plug properly. I had to splay the shroud slighly so they sit on the plug securely.
Gassing Station | Chimaera | Top of Page | What's New | My Stuff