A Funny Sort of a Starting Problem

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Davo
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A Funny Sort of a Starting Problem

Post by Davo »

I say it's a "funny" sort of a problem because it's not like it won't start, or it's intermittent, or anything else I've heard of.

New 3.5 RV8, new CD175 Stromberg/Zenith carbies, new electronic distributor, new Bosch BIM 024 ignition amp/module, (as seen on AULRO - it replaces the Lucas module), and everything else all as it should be set up, and in a Range Rover.

First thing in the mornings, when it's cold, (which over here means 20c or so), the thing refuses to start until it's been wound over a few dozen times. I started leaving just the fuel pump running first and that helped, but it still takes too long on the starter. Then, when it starts, it seems to run on only four or so cylinders and only settles after a bit of throttle to run up the revs to about 2000rpm, and then it will idle. If I switch off and start again, it starts right away, and any other time it's fine as well.

I pulled off the temperature compensators and replaced the o-rings, made sure the mixtures are right, the damper oils are right, the plugs look clean, and all I can think of is an air leak somewhere. The cold start mechanism leaks a little fuel, but I've never managed to fix that before!



unstable load
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Post by unstable load »

Ditch the Strombergs and find a set of non HIF SU's.?
Cheers,
John

Davo
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Post by Davo »

I know what you mean, but they and all their bits are a bit hard to find up here and I can't afford new ones. You'd think a pair of NOS CD175s would work for a while. (Well, these did for a little while.)

DaveEFI
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Post by DaveEFI »

Are they manual choke or FASD?
Dave
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kiwicar
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Post by kiwicar »

Hi
I would look at the pump and fuel lines and connections, it sounds to me that there is air getting into the lines and allowing the fuel to drain back to the tank causing the initial staring problem also check the fuel filter for cracks and leaks. I suspect the pump is tired and is struggling with air in the lines to pump enough fuel into the carb bowels until the air has cleared, to the extent the engine is partially draining one or both carb bowls as it starts. Fit a new Pump replace the filter and renew all the connections between fuel lines and I suspect it will come good. One other thing to check is the needle valves on the carb bowls the fuel could be draining back because they are not sealing properly.
best regards
Mike
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Davo
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Post by Davo »

Thanks, guys. They're manual choke carbies, and everything is new, (except for the actual fuel lines, though I did put new olives on everywhere I could), including the fuel pump and filter, and it's one of those big Delphi/Lucas/CAV diesel 296 filters, which fits right where the original filter assembly was. (But with an adaptor mounting.) I put it in because I couldn't find some of the seals for the original filter anymore, but I wonder if the 296, which is apparently meant to be in the suction side and not the pump side, is the trouble?

Anyway, I figured it must be a slight air leak that only works its magic overnight. It must be on one of the many, many connections these cars have. The funny thing is usually there's a slight petrol leak when this happens, but I haven't found anything obvious yet. I did rebuild the carbies and did the float valves as well . . . I'm avoiding pulling them off again with that 1/2" spanner cut in half and no room to swing it!

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ChrisJC
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Post by ChrisJC »

If it runs on 4 when it starts, that will indicate that it is just one carb that is faulty. Identify which one, and see if the float bowl is working properly.

Chris.
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Post by unstable load »

I'd also remove the plumbing and blow it through to clear any crud that may have snuck in while it was open last time.
Cheers,
John

Davo
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Re: A Funny Sort of a Starting Problem

Post by Davo »

So it took a "little" while, but I fixed it recently. The CD175s were overfuelling; some HIF6 SUs fixed the problem. I finally realised this when on starting the engine I had to run it at 2000rpm to burn off the extra fuel. I managed to buy some used ones over here, which was lucky since they're so rare.

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