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Post by guidedog on Aug 1, 2014 13:51:22 GMT
Last month I took the old boy/girl for a round trip to Dorset met up with fellow members at there monthly meet. All went well until going home. Loss of power due to blocked filters. We got home eventually ( 5mph up hill). I have now replaced the inline filter & cleaned the one in the tank. All lines where checked & cleaned. The car starts ok . ticks over at 600rpm @ 14d BTDC and revs upto 4000rpm @ 30d BTDC. I took out for a road test but no power up inclines. Here's is a brief history of what I have done. I have a Powerspark dizzy fitted to which I have fitted a with new cap, new plugs also a facet fuel pump fitted before I went to Dorset. I have tried resetting the S.U,s with a Colourtune & a Carbalancer.Which is not easy when you wear bifocal glasses Its all done by mirrors. My worst thought is the torque converter. Much appreciate any ideas gentlmen.
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Post by harvey on Aug 1, 2014 13:56:45 GMT
ticks over at 600rpm @ 14d BTDC That's a lot of initial advance. My worst thought is the torque converter. Possible, but pretty rare. If that were the case it wouldn't rev up at a standstill as well as having no performance on the road.
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Post by guidedog on Aug 1, 2014 14:28:57 GMT
Thanks for the quick response Harvey to the Its a relief about the torque converter. Regards to the timing the manual says 6D but there so many views as to what setting I have gone from 6D to 14D.
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Post by harvey on Aug 1, 2014 14:42:15 GMT
Regards to the timing the manual says 6D but there so many views as to what setting I have gone from 6D to 14D. Why would you add all that advance when it's the advance that causes pinking on inferior fuel? The general consensus is that in the days of Unleaded the timing needs to be retarded, not advanced.
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Post by guidedog on Aug 1, 2014 15:08:58 GMT
Food for thought Harvey, Looks like I will try from another direction tomorrow.
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Post by Simon H on Aug 1, 2014 15:49:14 GMT
I think you will have a totally different car if you set the timing at 4deg BTDC. I have mine 4 BTDC initial advance for petrol and it switches to 18 BTDC for LPG.
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Post by guidedog on Aug 1, 2014 16:12:49 GMT
Thank you Simon, Bob
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Post by Phil Nottingham on Aug 1, 2014 19:22:48 GMT
No way is that much advance correct at 600 idle 6-0 deg is the norm. Mine is 4 on 95 Octane unleaded
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Post by guidedog on Aug 2, 2014 9:25:51 GMT
Well I set up the timing for 4 degrees, its just the same maybe a tad worse. I have now been through the range 4--14 degrees with no change. Will now look into the cam lift.
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Post by Simon H on Aug 2, 2014 9:43:13 GMT
Going back to your original post. The loss of power problem seems to have occurred quite suddenly and you diagnosed the problem as blocked fuel filters and / or lines. Are you sure that the Facet pump survived the ingress of dirt? (Did you remember the micro filter on the inlet side of the pump?).
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Post by guidedog on Aug 2, 2014 10:08:35 GMT
Hi Simon Yes that was my first thought. Not knowing that there was a filter I assumed it be could a new pump. When coming back from Dorset the first inclination I had was surging uphill, i.e. temporary fuel loss.Which gradually got worse to a slow crawl on hills. The most obvious conclusion is fuel starvation, but as I said before 3500revs in the garage I am coming round to loss of torque.
Bob
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Post by enigmas on Aug 2, 2014 10:13:33 GMT
Whoa... take a breath before you start pulling the camshaft...unless of course, you feel the need! Your electronic ignition may have a glitch. Some modules have a range of functions including dwell extension and an advance limiter. Using a coil with the incorrect primary resistance can/will cause it to fail. I had a similar issue with a module on my daughters car. It would idle, rev and accelerate to moderate speeds but would seemingly retard itself at higher speeds. Substitute your electronic one with a points ignition to eradicate this possibility. As for the static timing, use a vacuum gauge to set for best vacuum reading at idle. It will probably be around 10 degrees or several more. This will give you best off idle torque.
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Post by guidedog on Aug 2, 2014 11:11:19 GMT
Thanks for that Enigmas. I still have my old dizzy will try on Monday morning. Its 1210 here in the UK so I off to the pub. You know it makes sense.
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Post by Simon H on Aug 2, 2014 11:12:12 GMT
....The most obvious conclusion is fuel starvation.... Bob I agree. Faulty or incorrectly set ignition would be unlikely to cause the surging you described although I'm not sure what would happen if the coil wasn't as specified for the Powerspark dizzy. I chose to have the recommended Lucas coil supplied with my Powerspark. Don't be tempted to dig deep into the worst case scenario side of things (torque converter, cam shaft, etc). I think you should try refitting the points distributor first of all and see what happens. If the car still misbehaves then it is almost certainly a fuel supply issue. It may be something completely unrelated to your recent changes such as a sticking float or some other carb issue.
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Deleted
Deleted Member
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Post by Deleted on Aug 2, 2014 15:10:51 GMT
If Guidedog is still suffering from fuel starvation when he's in the pub then he really does have a problem...
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Post by guidedog on Aug 2, 2014 15:35:33 GMT
I might be knocking on a bit but a pint of bitter still goes down well
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Post by guidedog on Aug 5, 2014 10:07:42 GMT
Problem solved. It was the induction manifold letting in air. Next thing I am going to try out Rolling Road.
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Post by guidedog on Aug 5, 2014 10:09:45 GMT
Sorry that should have said " induction manifold gasket"
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Post by enigmas on Aug 5, 2014 11:34:10 GMT
Guidedog what diagnostic technique did you use to find the problem? (If it was a big 'leak', it would have been running extremely lean...the idle would have been fast when the engine was up to running temperature, but it would have required a lot of choke on start up and it would have missed on some cyls. As for the loss of power, pulling the choke out...if a manual version, would have restored some of it)
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Post by guidedog on Aug 5, 2014 18:17:00 GMT
As said in an earlier note. I replaced the plugs, with the problem continuing I started from scratch again. As I removed the plugs I inspected the condition of them & noticed that on the 1 side I had No's 1 & 4 where light brown 2 & 3 where sooty. On the opposite side I & 4 where sooty, 2 & 3 where light brown. So I reasoned that air was getting in somewhere as I had replaced the heater pipe under the manifold some time back. The leak had to be small because the car started with no problem. As said before the engine revs where good at a standstill, but when power was required she just died. Whilst it is a lot better I do feel the car should be better than it is. Next a rolling road. It maybe me as my daily runner is an XF. Here's one for you John, marry up the V8 with the Jaguar 8 speed box. Now I am dreaming
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Post by enigmas on Aug 5, 2014 22:47:56 GMT
Guide dog if there's an inlet gasket issue, using a small plastic squirt bottle (water) or aero start directed at various points along the inlet manifold will either 'cut' a cyl or speed the engine indicating the problem area. From your last comment it sounds as though there's an overly rich issue from 1 carburettor feeding half the bank of cyls.
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Post by guidedog on Aug 6, 2014 19:30:00 GMT
Guidedog what diagnostic technique did you use to find the problem? (If it was a big 'leak', it would have been running extremely lean...the idle would have been fast when the engine was up to running temperature, but it would have required a lot of choke on start up and it would have missed on some cyls. As for the loss of power, pulling the choke out...if a manual version, would have restored some of it) The reason behind my conclusion is that on the left bank No's 1 & 7 plugs were light brown, No's 3 & 5 were sooty as these cylinders are fed by the same carburettor I came to the conclusion that a air leak was possible. I went out for quick run all seemed OK. Went out later with engine warm, back to square 1. I have now installed the old dizzy with points. When trying to achieve maximum revs the engine failed to reach 2500 revs continuing to encourage to go higher the engine just died. Checking fuel filter it was almost empty. I am back to my first thought fuel starvation. I am now in the process of cleaning again. Once again Enigmas thanks for your input. Will keep you posted
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