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Discussion Starter · #1 ·
Hi

My '86 rangie has developed a continual ticking noise and a choofing noise when the engine is worked hard.

The tick and the choof are reletive to engine speed. #5 cylinder plug was dry black fouled while all other plugs were good.

Car has done 110,000 kms and has not had any major work from what I can tell. 8:1 compression engine.

I have:
done a compression test - all cyclinders 170 psi +/- 3 psi when hot
replaced plugs and leads - no different
had a look at the rotor button and cap, don't look bad but don't really know what I am looking for
checked timing, around 0° btdc as per manual.
checked earth strap to the ignition coil, was perfect both ends
replaced ignition coil

Does anyone have any ideas? I think i will have to pull the heads and check out the cam, which I am not real keen on doing.

Thanks

Dave
 

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You could check the cam by taking measurements at the rocker arm. That would be a logical next step.

JP
 

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Couln't ticking be exhaust leak at head/manifold and choofing be fan clutch sticking?

T
 

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Discussion Starter · #4 ·
OK

The ticking is not a problem as it is just the injectors, odd that I haven't noticed them before. The injector cleaner may be making them noisy but i think it's just me.

Before I go playing with the internals of the engine I am am trying to redo all my exhaust joints with muffler putty, so far no luck but haven't got to far. The airbox side lower manifold flange is a bitch the damn chassis cross-member stops you pulling that piece out ........grrrr

Anyways, thanks for the ideas guys.

Pendy, if i take the rocker covers off and measure the gap pushrod (or valve) to rocker, won't it be all screwed up cos some lifters will have leaked down and others not???

Thanks again

dj
 

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A compression test might not be out of order here as well. D'Oh, you already did that, maybe a vaccum test? It could give you an idea of the condition of the cam wihtout any disassembly.
 

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Dave J said:
OK

The ticking is not a problem as it is just the injectors, odd that I haven't noticed them before. The injector cleaner may be making them noisy but i think it's just me.

Before I go playing with the internals of the engine I am am trying to redo all my exhaust joints with muffler putty, so far no luck but haven't got to far. The airbox side lower manifold flange is a bitch the damn chassis cross-member stops you pulling that piece out ........grrrr

Anyways, thanks for the ideas guys.

Pendy, if i take the rocker covers off and measure the gap pushrod (or valve) to rocker, won't it be all screwed up cos some lifters will have leaked down and others not???

Thanks again

dj

That is always a possibility. You can measure the compressed height of the spring at what appears to be full lift. For a quick check and then try to do more accurate testing on any suspect lobes. Fact is that there is a good chance, because of your vintage vehicle that the cam is bad. If you cannot account for a running problem in other areas that is what it will be. Do a power balance test before pulling your valve covers. Set the idle fairly low, and pull each spark plug wire one at a time and record the idle drop. You will have to disable the Idle Air Control first. And try not to shock yourself. Then try to test the valvetrain for any cyclinders that show very little or no power drop for the engine.

The idea of measuring the valve is to measure is when it is fully open. Not the gap left at rest. It is hard to be very accurate when doing this. You can spin the engine over during testing, with the ignition disabled, to build up oil pressure in the lifters. But the idea is to find a valve that is barely opening so do not confuse yourself with the other details of tying to test. That is what you are looking for.

If the injector pulse is concerning you, I am guessing this is the first time you have tried to tackle any sort of problem with an engine like this. Take your time and read up on the subject. It is possible a book may make more sense then some guy on the internet who is tired of typing for your enjoyment.

JP
 

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Discussion Starter · #7 ·
PT thanks, yes a vacuum test would be valuable.

Pendy, thanks for your help, I will look for valves that don't cut it.

pendy said:
tired of typing for your enjoyment.

JP
hmmm, forgive me for wasting your time.

DJ
 

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PTSchram said:
Don't worry about that, his time isn't worth much :flipoff2:
Watch it, you may become my new minion, price gouger.

JP
 

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I had to charge him extra, for his pet.

Not sure why I will charge you extra yet.
 
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