SR3 1500 misfire after 10 month layup
Discussion
Hi guys, i could do with a little help regarding whats next in the process.
Just to put you in the picture, i stopped using my Rad in December of last year. admittedly i used no special treatment to lay her up.
I was asked if i would take my rad out of storage (trying to sell her but don't have the need or desire to) to one of these driver experience days at the Prodrive track in Kenilworth, so that the public could pay for rides etc.
Before i got to the event she had a spanner check, oil and filter change and the brakes were bled through. I filled the fuel tank from the jerry cans that were filled 10 months ago (but were sealed) and then went to the BP and and filled the Jerry cans with 60 litres of finest super.
At the event, she ran like a breeze for the morning (first 1 hour of running). I wasn't driving, but a young and upcoming driver pedaled it with paying passengers.
I made it clear to the driver that he could rev it to the last green light as there was no need to go to the last 2 red lights.
she ran for about 1 hour taking about 8 passengers with no problems. At one point i heard it coming down the straight and a misfire had developed. the driver pulled in and i had a look all over but could see no problems visible.
The fuel warning light was not on, but i put some fuel in just in case. she took about 30 litres of fuel. The car returned to the track, but a misfire was still evident at the upper end of the rev range.
whilst at the track i took an opportunity to drain the float chambers, fit a set of older plugs and generally check what i could. I did wonder if the fuel filter was blocked and replaced one in the engine bay as i had a spare. I do believe that the engine bay fuel filter is not standard and that the previous owner installed it.
Anyway the fuel flow that was being delivered was delivering fuel at about 500ml in 27 seconds which seamed ok to me. what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all.
The engine has done 30 hours of track-day use and not being revved past the last green light (well mostly)
its a 2002 car with carburettors.
I have now removed the side pod and replaced the primary fuel filter and left in it situ. the fuel pump has no debris in it and there was no evidence of the dreaded tank breakup foam in the filter or the mouth of the pump.
when checking the fuel delivery with the new filter there was an improvement. fuel delivery is now about 20 seconds to deliver 500ml.
anyway, i have it at home now and i have done the following:-
New spark plugs
checked the leads for resistance / continuity. I spoke with the owner of Magnacore and he doubted that there was anything wrong with the leads but he gave me pointers regarding what might to look for that would lead to the high end misfire. i check the leads and found that on the coil end i had 2 leads that had a damaged phosphor bronze connector (these connect in to the coil outlets). I hooked out the broken bits and replaced the leads with some that the previous owner had given me when i purchased the car.
Before installing the replacement leads i checked the for resistance and continuity and all was fine 2.2k ohm per foot.
drained down the fuel tank to empty and refilled with new fresh fuel. still no change in the misfire. (when revved to 9,000k at the very top you can just perceive of a misfire at the vey top.
i had checked all of the connection on the ignition circuit and cleaned with brake cleaner and blown every thing out. retested the performance and still no change.
next i removed the carbs and stripped them down. all jets were removed and blow through.
remounted the carbs and still a misfire persists.
Then I removed the alternator stator housing to inspect the crank sensor. no problems found in that area (no debris around the pick-up). measured the resistance and at round 220 ohms.
engine starts and runs fine until the top end of the rev range.
Air filter cleaned and re-lubricated
Still no change.
If anybody has any clues to this particular problem i would appreciate your input.
I have a mechanical / electrical background and this one has me stumped!
Oh forgot to mention that i had a look at the coil relay, so will change then next.
if all else fails i will get it over to radical and let them sort it. Like this it cant be used or sold!
Dario
Just to put you in the picture, i stopped using my Rad in December of last year. admittedly i used no special treatment to lay her up.
I was asked if i would take my rad out of storage (trying to sell her but don't have the need or desire to) to one of these driver experience days at the Prodrive track in Kenilworth, so that the public could pay for rides etc.
Before i got to the event she had a spanner check, oil and filter change and the brakes were bled through. I filled the fuel tank from the jerry cans that were filled 10 months ago (but were sealed) and then went to the BP and and filled the Jerry cans with 60 litres of finest super.
At the event, she ran like a breeze for the morning (first 1 hour of running). I wasn't driving, but a young and upcoming driver pedaled it with paying passengers.
I made it clear to the driver that he could rev it to the last green light as there was no need to go to the last 2 red lights.
she ran for about 1 hour taking about 8 passengers with no problems. At one point i heard it coming down the straight and a misfire had developed. the driver pulled in and i had a look all over but could see no problems visible.
The fuel warning light was not on, but i put some fuel in just in case. she took about 30 litres of fuel. The car returned to the track, but a misfire was still evident at the upper end of the rev range.
whilst at the track i took an opportunity to drain the float chambers, fit a set of older plugs and generally check what i could. I did wonder if the fuel filter was blocked and replaced one in the engine bay as i had a spare. I do believe that the engine bay fuel filter is not standard and that the previous owner installed it.
Anyway the fuel flow that was being delivered was delivering fuel at about 500ml in 27 seconds which seamed ok to me. what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all.
The engine has done 30 hours of track-day use and not being revved past the last green light (well mostly)
its a 2002 car with carburettors.
I have now removed the side pod and replaced the primary fuel filter and left in it situ. the fuel pump has no debris in it and there was no evidence of the dreaded tank breakup foam in the filter or the mouth of the pump.
when checking the fuel delivery with the new filter there was an improvement. fuel delivery is now about 20 seconds to deliver 500ml.
anyway, i have it at home now and i have done the following:-
New spark plugs
checked the leads for resistance / continuity. I spoke with the owner of Magnacore and he doubted that there was anything wrong with the leads but he gave me pointers regarding what might to look for that would lead to the high end misfire. i check the leads and found that on the coil end i had 2 leads that had a damaged phosphor bronze connector (these connect in to the coil outlets). I hooked out the broken bits and replaced the leads with some that the previous owner had given me when i purchased the car.
Before installing the replacement leads i checked the for resistance and continuity and all was fine 2.2k ohm per foot.
drained down the fuel tank to empty and refilled with new fresh fuel. still no change in the misfire. (when revved to 9,000k at the very top you can just perceive of a misfire at the vey top.
i had checked all of the connection on the ignition circuit and cleaned with brake cleaner and blown every thing out. retested the performance and still no change.
next i removed the carbs and stripped them down. all jets were removed and blow through.
remounted the carbs and still a misfire persists.
Then I removed the alternator stator housing to inspect the crank sensor. no problems found in that area (no debris around the pick-up). measured the resistance and at round 220 ohms.
engine starts and runs fine until the top end of the rev range.
Air filter cleaned and re-lubricated
Still no change.
If anybody has any clues to this particular problem i would appreciate your input.
I have a mechanical / electrical background and this one has me stumped!
Oh forgot to mention that i had a look at the coil relay, so will change then next.
if all else fails i will get it over to radical and let them sort it. Like this it cant be used or sold!
Dario
Edited by DarioT on Saturday 6th November 18:53
The bit that stands out is this bit >
"what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all."
Presumably you mean it went cloudy after actually laying in the 3's tank for about five minutes?
Surely it's got to be the tank foam breaking down? I'm no expert on what that foam actually is, but maybe whatever it's breaking down into is so fine that even the filters won't stop it? .......... I'd expect the fuel to be as crystal clear at the combustion point as it is when it comes out of the PFS forecourt petrol pump.
"what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all."
Presumably you mean it went cloudy after actually laying in the 3's tank for about five minutes?
Surely it's got to be the tank foam breaking down? I'm no expert on what that foam actually is, but maybe whatever it's breaking down into is so fine that even the filters won't stop it? .......... I'd expect the fuel to be as crystal clear at the combustion point as it is when it comes out of the PFS forecourt petrol pump.
Edited by splitpin on Saturday 6th November 19:51
splitpin said:
The bit that stands out is this bit >
"what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all."
Presumably you mean it went cloudy after actually laying in the 3's tank for about five minutes?
Surely it's got to be the tank foam breaking down? I'm no expert on what that foam actually is, but maybe whatever it's breaking down into is so fine that even the filters won't stop it? .......... I'd expect the fuel to be as crystal clear at the combustion point as it is when it comes out of the PFS forecourt petrol pump.
I here ya!"what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all."
Presumably you mean it went cloudy after actually laying in the 3's tank for about five minutes?
Surely it's got to be the tank foam breaking down? I'm no expert on what that foam actually is, but maybe whatever it's breaking down into is so fine that even the filters won't stop it? .......... I'd expect the fuel to be as crystal clear at the combustion point as it is when it comes out of the PFS forecourt petrol pump.
Edited by splitpin on Saturday 6th November 19:51
I also don't know what broken down fuel foam looks like?
but if its getting through 2 in-line brand new fuel filters (probably 20 micro filtration?) what harm can it do, and why is it not constant misfire. ok its not on load, but as i build up the revs to all green lights i can definitely perceive a misfire.
I did drain a fair bit out of the carbs and allowed it to settle in a jug today and that didn't go cloudy.
I do wonder if i have bought some piss poor fuel. Must go and get some shell.
If the tank is breaking down, i saw no evidence in the primary filter or fuel pump.
my guess is to take it to a track and ask to do a handful of laps for a few laps for a drink. Failing that it can go to Radical and let them stick it on their rolling road as its fully repeatable and does not need cornering or braking inertia to induce the the misfire.
Dario
splitpin said:
The bit that stands out is this bit >
"what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all."
Presumably you mean it went cloudy after actually laying in the 3's tank for about five minutes?
Surely it's got to be the tank foam breaking down? I'm no expert on what that foam actually is, but maybe whatever it's breaking down into is so fine that even the filters won't stop it? .......... I'd expect the fuel to be as crystal clear at the combustion point as it is when it comes out of the PFS forecourt petrol pump.
I here ya!"what i did find is that the fuel that came out was clear (as expected) but when allowed to stand for about 5 minutes it went cloudy which was quite a surprise. I have no answer to this cloudiness at all."
Presumably you mean it went cloudy after actually laying in the 3's tank for about five minutes?
Surely it's got to be the tank foam breaking down? I'm no expert on what that foam actually is, but maybe whatever it's breaking down into is so fine that even the filters won't stop it? .......... I'd expect the fuel to be as crystal clear at the combustion point as it is when it comes out of the PFS forecourt petrol pump.
Edited by splitpin on Saturday 6th November 19:51
I also don't know what broken down fuel foam looks like?
but if its getting through 2 in-line brand new fuel filters (probably 20 micro filtration?) what harm can it do, and why is it not constant misfire. ok its not on load, but as i build up the revs to all green lights i can definitely perceive a misfire.
I did drain a fair bit out of the carbs and allowed it to settle in a jug today and that didn't go cloudy.
I do wonder if i have bought some piss poor fuel. Must go and get some shell.
If the tank is breaking down, i saw no evidence in the primary filter or fuel pump.
my guess is to take it to a track and ask to do a handful of laps for a few laps for a drink. Failing that it can go to Radical and let them stick it on their rolling road as its fully repeatable and does not need cornering or braking inertia to induce the the misfire.
Dario
Simon T said:
1. The tank foam breaks into particles about 2-5mm so its not that.
2. If its only at the top of the rev range could it be an adjustable rev limiter fitted to the car?
3. Got a data logger on the car?
Simon
Hi Simon, Thanks for the heads up about the foam. I did not know what i was going to be looking for, but as you say this is not foam.2. If its only at the top of the rev range could it be an adjustable rev limiter fitted to the car?
3. Got a data logger on the car?
Simon
There is no adjustable rev limit on the car that i am aware of as it looks all bog standard as it came out of the factory in 2002.
No data logger i'm afraid as its only a play thing.
what do you think about the coil pack. I tried to test the windings for resistance, but not knowing which is primary / secondary winding and which cable is which is a certain set back.
Bugger!
Dario
Lateral thought, probably 'daft', but easy enough to try ........
If you were running on the 'quiet' exhaust, try the race can in lieu (beggar the neighbours
) and see what happens.
Reason for suggesting is that the other day I was watching an SR4 running the old teapot sealed for life quiet exhaust and it was as flat as a pancake - wasn't revving freely at all and it was misfiring at the top end, sounded horrible - which was then changed to the far less restrictive race can, whereupon it was revving freely and with no misfiring at all, sounded beautiful, sweet as a nut. The difference was simply astonishing ........... just a change of exhaust, but it sounded like it had had an engine change.
Just a thought.
If you were running on the 'quiet' exhaust, try the race can in lieu (beggar the neighbours
) and see what happens.Reason for suggesting is that the other day I was watching an SR4 running the old teapot sealed for life quiet exhaust and it was as flat as a pancake - wasn't revving freely at all and it was misfiring at the top end, sounded horrible - which was then changed to the far less restrictive race can, whereupon it was revving freely and with no misfiring at all, sounded beautiful, sweet as a nut. The difference was simply astonishing ........... just a change of exhaust, but it sounded like it had had an engine change.
Just a thought.
splitpin said:
Lateral thought, probably 'daft', but easy enough to try ........
If you were running on the 'quiet' exhaust, try the race can in lieu (beggar the neighbours) and see what happens.
Reason for suggesting is that the other day I was watching an SR4 running the old teapot sealed for life quiet exhaust and it was as flat as a pancake - wasn't revving freely at all and it was misfiring at the top end, sounded horrible - which was then changed to the far less restrictive race can, whereupon it was revving freely and with no misfiring at all, sounded beautiful, sweet as a nut. The difference was simply astonishing ........... just a change of exhaust, but it sounded like it had had an engine change.
Just a thought.
now that is a thought, although it was running with its quiet exhaust it is an old one. i do have another quiet one which i could put on which is newer.If you were running on the 'quiet' exhaust, try the race can in lieu (beggar the neighbours
) and see what happens.Reason for suggesting is that the other day I was watching an SR4 running the old teapot sealed for life quiet exhaust and it was as flat as a pancake - wasn't revving freely at all and it was misfiring at the top end, sounded horrible - which was then changed to the far less restrictive race can, whereupon it was revving freely and with no misfiring at all, sounded beautiful, sweet as a nut. The difference was simply astonishing ........... just a change of exhaust, but it sounded like it had had an engine change.
Just a thought.
and as you say i could annoy the neighbours with the race can on.
Nice point, Ill try it later on today or tomorrow.
Dario
After a few hours at the radical works and my car being worked on by Jamie, we found the culprit. The MBE ECU is defective. having tried the normal stuff like the plugs, leads and coil they found an obsolete 992 ECU and hey presto all is well.
Strangely when Jamie handed me the ECU he said it was rattling. We opened it up there and then and found this!
Thanks to all for providing guidance on what to look for.......
I don't believe for one moment that i could have discovered this fault without a rolling road and a spare unit to try.
Thanks Jamie and thanks to Radical and Paul WIdnal for getting me in so quickly.
whilst i'm here i have decided to have the car suspension and geometry set, might as well.
Dario
Strangely when Jamie handed me the ECU he said it was rattling. We opened it up there and then and found this!
Thanks to all for providing guidance on what to look for.......
I don't believe for one moment that i could have discovered this fault without a rolling road and a spare unit to try.
Thanks Jamie and thanks to Radical and Paul WIdnal for getting me in so quickly.
whilst i'm here i have decided to have the car suspension and geometry set, might as well.
Dario
Edited by DarioT on Wednesday 10th November 19:07
BertBert said:
well we'd have taken a while to diagnose that on the internet! I assume you'll be getting your soldering iron out to fix it as a spare?
Bert
did you see the size of the legs on that chip........ i don't think i'll do it, might send it to MBE, but likely to do nothing with it as its not in any racing series.Bert
Some footage from the test bay
with misfire
http://www.youtube.com/watch?v=qPvloa_WfIg
with misfire fixed
http://www.youtube.com/watch?v=J-4vOIW7AzI
Dario
with misfire
http://www.youtube.com/watch?v=qPvloa_WfIg
with misfire fixed
http://www.youtube.com/watch?v=J-4vOIW7AzI
Dario
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