Ollie Posted July 19, 2006 Report Share Posted July 19, 2006 Can anyone help me on this one? In simple terms, once my car has warmed up it gasps for breath and shuts down. Particulary irritating, as the problem has appeared quite suddenly (after some time being off the road over the winter, although it had been started up every month or so) The car is a CR PI with normal ignition components, Bosch fuel pump (Revington), unleaded metering unit, modified throttle linkage (Prestige). The car starts normally and will run for several miles or idle on the drive for 1/2 an hour, no problem. Then it starts to die fairly progressively. Just before it finally stops, and you 'blip' the accelerator it looses all power - it wont rev but will idle, but soon after it wont idle either. I have had a look at the butterflies just before it konks out and if they are opened, say 1/8", it is as though all the air rushes into the cylinders but there is no fuel to go with it and it stops. Things I have checked and confirmed OK are: coil, condenser, fuel pressure (steady 105 psi right up to the point when it finally stops), air filter, MU return line is clear, point, tappets, plugs look almost perfect, timing, pulses in the injector lines, fuel pre filter. I am struggling on this one, coz I think I have covered most of the obvious things that might change as the engine warms up. Any suggestions - I really want this car on the road. Quote Link to post Share on other sites
Guest nco Posted July 20, 2006 Report Share Posted July 20, 2006 HI Ollie, Sounds a very strange problem. I would supsect it is electrical and something breaking down with temperature! You say you have checked the condensor and coil. How did you do this? I would start by swapping these two components with new ones. I cant see how the throttle linkage and butterflies would change mode of operation between first starting and later running. Only other option I can think of is fuel delivery - pump/prv and MU though again you say you have checked them. I'd start by now swapping componets with spares - start with the condensor, points and coil. followed by new rotor arm and cap. Let us know how you get on! Neil Quote Link to post Share on other sites
rarbowman Posted July 20, 2006 Report Share Posted July 20, 2006 Can anyone help me on this one? In simple terms, once my car has warmed up it gasps for breath and shuts down. Particulary irritating, as the problem has appeared quite suddenly (after some time being off the road over the winter, although it had been started up every month or so) The car is a CR PI with normal ignition components, Bosch fuel pump (Revington), unleaded metering unit, modified throttle linkage (Prestige). The car starts normally and will run for several miles or idle on the drive for 1/2 an hour, no problem. Then it starts to die fairly progressively. Just before it finally stops, and you 'blip' the accelerator it looses all power - it wont rev but will idle, but soon after it wont idle either. I have had a look at the butterflies just before it konks out and if they are opened, say 1/8", it is as though all the air rushes into the cylinders but there is no fuel to go with it and it stops. Things I have checked and confirmed OK are: coil, condenser, fuel pressure (steady 105 psi right up to the point when it finally stops), air filter, MU return line is clear, point, tappets, plugs look almost perfect, timing, pulses in the injector lines, fuel pre filter. I am struggling on this one, coz I think I have covered most of the obvious things that might change as the engine warms up. Any suggestions - I really want this car on the road. have you checked that fuel is flowing BACK thru the prv into the top of the tank. It should be under quite high preasure and is best checked by removing the rear pipe from the valve (don't smoke!) I only say this because if you look at my 'indignity' thread this was the cause of the problem Quote Link to post Share on other sites
Mike G Posted July 20, 2006 Report Share Posted July 20, 2006 Ollie As it's a CR, you may be getting 12 volts constantly to the coil from somewhere. This would cause the coil to overheat and start to breakdown. You could check using a voltmeter, or check the coil temperature, once the car has wormed up. Mike G Quote Link to post Share on other sites
Goswell Posted July 20, 2006 Report Share Posted July 20, 2006 I had a fault in either the Coil or Condensor which would cut out the spark when hot. Because you say the car will idle I wouldn't think it's electrical. Sounds more like fuel starvation which could be down to cavitation, I presume you have a full tank, or lack of fuel pressure, which could be the PRV. Quote Link to post Share on other sites
Ollie Posted July 21, 2006 Author Report Share Posted July 21, 2006 Ollie As it's a CR, you may be getting 12 volts constantly to the coil from somewhere. This would cause the coil to overheat and start to breakdown. You could check using a voltmeter, or check the coil temperature, once the car has wormed up. Mike G Mike I did wonder about the voltage at the coil - my voltmeter said 12V so I thought I might have cooked it However, I swapped it out for a new 12V coil and the problem didn't go away. Ollie I had a fault in either the Coil or Condensor which would cut out the spark when hot. Because you say the car will idle I wouldn't think it's electrical.Sounds more like fuel starvation which could be down to cavitation, I presume you have a full tank, or lack of fuel pressure, which could be the PRV. I swapped out the coil and condensor for new items and the problem stayed. The fuel tank is about 3/4 full and I checked the fuel pressure at the MU which was fairly steady at about 105 psi. Although the pressure is steady I don't know if there is flow there. Can you get steady pressure and a drop off in flow from a Bosch pump?? One way might be if, as you say, all the flow is going round the PRV back to the tank. I've just got to work out how to check this..... HI Ollie, Sounds a very strange problem. I would supsect it is electrical and something breaking down with temperature! You say you have checked the condensor and coil. How did you do this? I would start by swapping these two components with new ones. I cant see how the throttle linkage and butterflies would change mode of operation between first starting and later running. Only other option I can think of is fuel delivery - pump/prv and MU though again you say you have checked them. I'd start by now swapping componets with spares - start with the condensor, points and coil. followed by new rotor arm and cap. Let us know how you get on! Neil Neil I have done what you suggets with the condensor and coil and will follow with the rest - I just need to go and buy a set. I'll let you know how I get on. Ollie have you checked that fuel is flowing BACK thru the prv into the top of the tank. It should be under quite high preasure and is best checked by removing the rear pipe from the valve (don't smoke!) I only say this because if you look at my 'indignity' thread this was the cause of the problem Do you mean that I need to check that all the fuel is going back to the tank rather than going forward to the MU? This might explain if no fuel is going forward? I am just a bit concerned that there could be a lot of fuel to collect/measure. I am not that familiar with the operation of the PRV, but I thought it was, pretty much, a fixed device. Maybe if the outlet got blocked (somehow) it would stop fuel going forward. That has just reminded me, when I removed the rubber hose at teh MU, to install the pressure gauge, there was no appreciable fuel leakage. Could this mean that the fuel supply pipe is blocked??? Quote Link to post Share on other sites
rarbowman Posted July 21, 2006 Report Share Posted July 21, 2006 You should check to see if fuel is comming out of the rtrn from the prv, by disconnecting the pipe that goes from the prv to the top of the tank (disconect from the prv end) with the pump running it should come out under preasure. There is a filter in the prv also that is worh checking. With the pump off very little will come from the fuel hose at the MU. Idid have the exact same prob and it proved to be a faulty prv Quote Link to post Share on other sites
Ollie Posted August 2, 2006 Author Report Share Posted August 2, 2006 Thanks for everyone's comments - I have tried everything suggested over the past couple of weeks. However, like all all these types of problems, it has just gone away!!! I put everything back to how it was at the start of the investigation and took the car for a longish run yesterday. It mis-fired rally badly and eventually cleared. I have run it for about 100 miles today in a variety of traffic - fast flowing and queues - and it hasn't missed a beat! Typical! Good thing is - it's back on the road! Quote Link to post Share on other sites
marvmul Posted August 2, 2006 Report Share Posted August 2, 2006 No one mentioned the rotor : this is certainly something to try after the investigations you've made already. It's common for a failing rotor to behave like that. Quote Link to post Share on other sites
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