Josh NZ Posted November 3, 2013 Author Share Posted November 3, 2013 Agreed on both points! I too thought the compression theory was odd, but I think he was going on the assumption that it was doing the wierd stuff for ages (as I had forgotten to mention to him that it was laid up for a while and going well prior to that) so I can see where he may have been confused. After I told him that, he immediately told me that it was running so rich that the plugs were pretty much shot and he agreed that there's certainly something amiss with the fuelling system. He's just taken delivery of the stromberg special tools (as they were out on loan) so now they can start to get the service items changed and the mixture sorted, then we have a firm base to go on. In regards to the specialists, they have an excellent rep from people who I know have used them in the past, and the guy looking after my truck is conscious of blowing out costs so he is trying to keep time spent on the truck to a minimum so as not to blow my budget. I'm more than happy with them doing the work. I have both the S3 manual + V8 supplement as well as the haynes manual and a very nice multimeter but unfortunately I'm not much good at fine tuning items. I've recently sold my wee runabout so I have some spare funds and it made sense to me to get the specialists to look it over, that way the risk is on them IMO. Thanks for your help guys, I'll post up with what he says tomorrow when he calls me. Quote Link to comment Share on other sites More sharing options...
Josh NZ Posted November 11, 2013 Author Share Posted November 11, 2013 So, the garage called with some odd news. The starting and idle is nice and steady now, but when the truck gets loaded up in 2nd or higher with a footful applied, it misfires terribly and won't accelerate at all. The compression test came back good, and they checked the camshaft lift on the valves etc and its all fine. Is it still a fuelling issue? On light throttle the truck is fine. The dash pots are full, and the points, cap, leads, plugs were replaced. The rocker assemblies were also replaced due to having no oil flowing through at all and were worn out completely on the shafts. I'm so close to getting it sorted. I can't give up now! Josh Quote Link to comment Share on other sites More sharing options...
disco2hse Posted November 11, 2013 Share Posted November 11, 2013 How's the fan belt? Is it slack? Does it do it of you take the fuel cap off? Are there leaks in the exhaust system? Cracked, warped or leaking exhaust manifold? What about the inlet manifold, is it leaking? Was it properly sealed after dealing with the cam and lifters? Is the fuel pump pushing sufficient fuel through? You can test this by: disconnect at the fuel filter end, feed the fuel line onto a measuring jug, turn on the key for 30 seconds and switch off and read how much fuel went into the jug. The pump should move about 2l/min. What about the crankcase breather hoses, are they all in good nick and the vacuum hoses? Is the air cleaner in good condition, does it need changing? You just had the carbs rebuilt right? Are they properly tuned and balanced? Is there variation between idle timing and accelerated timing? Quote Link to comment Share on other sites More sharing options...
discomikey Posted November 11, 2013 Share Posted November 11, 2013 check and adjust the timing, if nothing else it will run better than before also chack the vacuum advance system hasnt siezed up with little use. this would display these symptoms Quote Link to comment Share on other sites More sharing options...
deep Posted November 12, 2013 Share Posted November 12, 2013 The symptoms strongly suggest the diaphragms in the carburettors are cracked. They may look okay but if you take them out and stretch them I bet you'll find a split or a crack, which is letting air past. Failing that (notwithstanding good suggestions above), take the fuel line off and check the fuel supply is good (easy with an electric pump but it helps to use a jar to catch the petrol and an assistant to turn the key on and off). If plenty of petrol is getting to the carbs, you still may have a jammed float needle on one carb (unlikely but possible). It is also just possible there is water in your petrol (check the filter). It very much sounds like a fuel issue. You'll get there! Quote Link to comment Share on other sites More sharing options...
Josh NZ Posted December 22, 2013 Author Share Posted December 22, 2013 Right, its been a while but i'm back! I'm very pleased to say that the truck is now mechanically sound! A few major parts were replaced and the issue turned out to be that the left hand carburettor was unserviceable. They tried everything to get it running properly and said that the main jet was so badly worn out that they couldn't lean it out enough to get a decent mixture on idle. Compression was tested and 7 cyls came back with 120psi and the last one being 110psi. Cam lift was measured and came back fine. They then replaced the points, condenser, cap, plugs and leads. Took the rocket covers off and found zero oil flow to the rocker assemblies, and the rocker arms had worn into the shafts so much that they were unable to slide along the shafts themselves. So a new assembly went on there as well. A replacement pair of carbs off an RR with 30,000km on the clock were fitted, balanced and found to have completely fixed the problem. They also found a vacuum leak in my diff-lock system which was preventing it from working so they disconnected it temporarily until I can afford to take it back or fix it myself. So I am a happy chappy! The truck drives so well now, plenty of grunt and has got a lot better on fuel! I'm now doing 450kms to a tank of fuel so I'm rapt. Once I got it home, I had a fiddle with the electrics to try and resurrect my dead oil pressure gauge, cold start and oil pressure lights. The gauge sender was cooked, so I went down to the local motor factors and bought a cheap electrical gauge, used the sender and got a result! Now reading 30 ft/lb. Cold start warning light is sporadic, I think the switch is past its best but it can make it go when I press the switch in myself so I think ill try and find a new one. Still have no idea why my oil pressure light wont work. The bulb works and the wiring is in good nick as well. Can the pressure switch be known to go duff? But all in all, very pleased! Josh Quote Link to comment Share on other sites More sharing options...
deep Posted December 22, 2013 Share Posted December 22, 2013 Right, its been a while but i'm back! I'm very pleased to say that the truck is now mechanically sound! A few major parts were replaced and the issue turned out to be that the left hand carburettor was unserviceable. They tried everything to get it running properly and said that the main jet was so badly worn out that they couldn't lean it out enough to get a decent mixture on idle. Compression was tested and 7 cyls came back with 120psi and the last one being 110psi. Cam lift was measured and came back fine. They then replaced the points, condenser, cap, plugs and leads. Took the rocket covers off and found zero oil flow to the rocker assemblies, and the rocker arms had worn into the shafts so much that they were unable to slide along the shafts themselves. So a new assembly went on there as well. A replacement pair of carbs off an RR with 30,000km on the clock were fitted, balanced and found to have completely fixed the problem. They also found a vacuum leak in my diff-lock system which was preventing it from working so they disconnected it temporarily until I can afford to take it back or fix it myself. So I am a happy chappy! The truck drives so well now, plenty of grunt and has got a lot better on fuel! I'm now doing 450kms to a tank of fuel so I'm rapt. Once I got it home, I had a fiddle with the electrics to try and resurrect my dead oil pressure gauge, cold start and oil pressure lights. The gauge sender was cooked, so I went down to the local motor factors and bought a cheap electrical gauge, used the sender and got a result! Now reading 30 ft/lb. Cold start warning light is sporadic, I think the switch is past its best but it can make it go when I press the switch in myself so I think ill try and find a new one. Still have no idea why my oil pressure light wont work. The bulb works and the wiring is in good nick as well. Can the pressure switch be known to go duff? But all in all, very pleased! Josh Great news, Josh. A new carb has to be a lot cheaper than major motor work! I don't have a cold start warning light on mine but have had in the past. In that case, there was a mechanical connection to the cable which could be adjusted. Any sign of potential to do that on yours? It could be as simple as adjusting cable free-play at the carb end. With your oil pressure sender, you could measure the resistance with an ohm meter and compare the difference with the engine off or running (use alligator clips - it's not a clever place to stick your fingers on a running motor!). That should tell you quickly if the switch is doing anything. Should! Don Quote Link to comment Share on other sites More sharing options...
tacr2man Posted December 25, 2013 Share Posted December 25, 2013 If you want to test the oil press sender , just earth the wire that goes to it this will cause the light to light , if it doesn't then its the switch , simple as that . Cold start light , is mech switch on cable , and earthed thru temp switch so that when you pull out choke the light doesnt work till upto temp then you push knob back in IIRC HTSH Quote Link to comment Share on other sites More sharing options...
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