v8 engine running rich and i have no mechanics in colombia!

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KatColombia

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Hi I have a Defender 90 v8 3.5 94 model, and I live in the countryside in Colombia, South America. There are no mechanics in this area that have any knowledge of this engine, so im kind of stuck, i am no mechanic myself!

The engine is running rich with crude gasoline coming on the exhaust. I have checked the spark plugs and the ones on the right side of the motor are black, on the left they seem fine. Sometimes the engine will not run smooth with a coughing action when you try to accelarate, but this happens only 5% of the time, at the same time when this happens it will idle low and will cut out when stationary.

I think i have a stromber carberautor with hiff 44, thats what i can work out by looking online

Another problem i have here are parts are 2 to 3 times the price as in the uk and take time to order. I was thinking of getting a rebuild kit for the right hiff to see is that cleans it up. Its 18 years old and im starting to realise has never been taken care of.

Any ideas/advice/positive thoughts pleaseeeee?!

Katherine
 
First thing I would do is check the dash pots on the top of the carbs. Take out the plungers and fill them with ATF before slowly inserting the plungers. Often these carbs run rich if the dash pots run dry. Take off the air intakes and make sure the carb pistons are free to move up and down in their bores by sliding them with your fingers. They should be silky smooth and not catch at any point. You can do this without having to dismantle the carbs. If any of the pistons are sticking then you have your answer. You will then need to strip the carbs and give them a good clean. Be careful not to bend the needles in the bottom of the carb pistons.
 
Checked the pistons and they are working smoothly and added AFT to the dash pots. These were lubed already but i added more. Still have the same problem. Im suprised at how little power and accelaration it has, especially on the slightest incline. For a V8 i would hope for a little more growl!

any more ideas?

Thanks
 
Sounds like it may be electrical problem with the sparks rather than a fuel issue. When was the last time the plugs were cleaned and gapped and/or tested? What condition are the plug leads in? Do you have a good fat spark on each plug? Is it electronic ignition or good old dizzy and coil with contact breaker? If so is the contact breaker clean and gapped properly? Is the dizzy advancing the timing properly when revved? Could be a mulitude of things.
 
Well that sounds about right! The electrics are in terrible shape due to 18 years of cutting and tapeing. I will go through what you suggested. Thank you its greatly appreciated

As far as electrics go is it a massive job to have them all replaced? Im guessing it is and not worth the expense

You want a holiday out to Colombia to fix a landrover??!!!!
 
KatColombia said:
Well that sounds about right! The electrics are in terrible shape due to 18 years of cutting and tapeing. I will go through what you suggested. Thank you its greatly appreciated

As far as electrics go is it a massive job to have them all replaced? Im guessing it is and not worth the expense

You want a holiday out to Colombia to fix a landrover??!!!!
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nice offer ! but my skin aint bullet proof....:D
 
Shifty1962 said:
Sounds like it may be electrical problem with the sparks rather than a fuel issue. When was the last time the plugs were cleaned and gapped and/or tested? What condition are the plug leads in? Do you have a good fat spark on each plug? Is it electronic ignition or good old dizzy and coil with contact breaker? If so is the contact breaker clean and gapped properly? Is the dizzy advancing the timing properly when revved? Could be a mulitude of things.
Click to expand...

But would this affect only 1 side of the carbuerator? The mechanic i use is suggesting that if it was an electrical fault both spark plugs on the right and the left woud be black, he suggests we buy the kit and strip, clean and replace parts in the carbuerator first.

Im a little lost here, the mechanics here are not like at home in the uk!
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KatColombia said:
But would this affect only 1 side of the carbuerator? The mechanic i use is suggesting that if it was an electrical fault both spark plugs on the right and the left woud be black, he suggests we buy the kit and strip, clean and replace parts in the carbuerator first.

Im a little lost here, the mechanics here are not like at home in the uk!

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Click to expand...
Firstly you will have two carbs unless the engine has been modded so its quite possible that only one bank of cylinders may be running rich. Although both carbs feed into the same manifold there is an element of one carb for one bank of cylinders due to the airflow inside the manifold.

If you have iffy plug leads on one bank of cylinders they will affect only that side of the engine. Its much easier and probably cheaper to change the plug leads and make sure the ignition system is efficient, including cleaning and gapping the plugs before messing around stripping carbs and playing with the mixture settings etc.

If you do strip the carbs then you will need to adjust for mixture, idle, and full throttle as well as balance them to get a smooth idle and strong pick up. Strombergs and SUs are a pain to set up properly but once done will give years of reliable service with little or no maintenance.

My advice is to make sure the IGNITION system is working well and if there is still a problem then turn your attention to the fuelling.
 
Shifty1962 said:
Firstly you will have two carbs unless the engine has been modded so its quite possible that only one bank of cylinders may be running rich. Although both carbs feed into the same manifold there is an element of one carb for one bank of cylinders due to the airflow inside the manifold.

If you have iffy plug leads on one bank of cylinders they will affect only that side of the engine. Its much easier and probably cheaper to change the plug leads and make sure the ignition system is efficient, including cleaning and gapping the plugs before messing around stripping carbs and playing with the mixture settings etc.

If you do strip the carbs then you will need to adjust for mixture, idle, and full throttle as well as balance them to get a smooth idle and strong pick up. Strombergs and SUs are a pain to set up properly but once done will give years of reliable service with little or no maintenance.

My advice is to make sure the IGNITION system is working well and if there is still a problem then turn your attention to the fuelling.
Click to expand...

Hi Shifty, I have checked the spark plugs now looking at the timing. I have found contrasting advice on the degrees for the timing. The manual says 5 degrees +/- 1 with the vacum not attached, but online I found a range of degrees suggested. What do you suggest?

Thanks again i am learning more about mechanics than ever before this week!
 
Go with the manual as it will give you a decent starting point. Timing is affected by many things including wear in the distributor and the drive gear as well as wear in the timing chain and gears. Once you get the motor running somewhere near to smooth you can then start to fine tune by minute manual adjustments to the dizzy timing. I never do this with timing lights and book figures but by how the engine sounds, how it restarts and how it pulls. Every engine is different even when new. This way you can often tune out any wear characteristics as long as the distrubutor is not on its last legs. If you can not get a constant timing reading and the motor just wont run evenly then consider a replacement dizzy or a rebuild of your existing one. In simple terms Advancing the timing makes the engine run stronger but take it too far and you will get pre ignition and hard or impossible starting from hot. Retarding the timing makes for a lazy engine that will not deliver its full power. The manual adjustments to the dizzy are minute in terms of rotational movement but they have large effects on how efficiently the engine will run.
 
We took a look at the distributor, the mechanic pushed it a couple of times and said it was fine?! Im not sure if this is a good test or not. Anyhow he says it looks fine. Then we checked the engine compression and each plug differered from 120 to 140, so i take it this means there are problems within the motor?

Thinking its better to sell this car on than keep trying!
 
Think I'd find a mechanic who knows what he's doing! Wear in a distributor wont necesssarily be visible, unless its completely shot, but will only show once its rigged up to a timing light and then you will see the timing wandering all over the place. No amount of adjusting will settle it down if that is the case. He wpuld also need to make sure the timing advance is working properly and you cant do that just by looking. You need a timing light.

Its not uncommon for compression between cylinders to vary but I've no idea what the V8 should be. As a guess I'd say all cylinders should be within 10% or better of each other. A simple way to show if the rings are worn is to put a small amount of engine oil into the spark plug hole and see if the compression improves. If so then the rings and/or bores need attention. Another cause may be the valves not seating properly but that is not so easy to determine unless you take the heads off. A leakdown test will be affected by worn rings.
 
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Some fair advice to follow but be aware that wandering timing can also be due to a worn and slack timing chain. As has been said, the compression test needs to be done wet and dry.

It would also be a good idea to remove and clean (or replace) the engine breathers.
 
My thoughts on this is find a motorcycle mechanic, they will understand twin carbs etc if you can't find a good car mechanic
 
Thank you for your advise. Its troubling as this mechanic im using now is one of the more certified in my town! Im happy to pay out to someone who knows what they are doing, but paying out and not even being confident in the work leaves me lost. The way things are done here its almost impossible to get diagnostics done in order, correctly and in a short space of time. Anyhow may have to head to the big city and try and find a landrover specific mechanic, not so easy here!

I went driving yesterday after a month away and we had problems getting out of a small hill with lots of black smoke pouring out of the back. I had absolutely no force, needing a run up on the flat to ensure it didnt die out up the slope. It actually seems worse. I just wanted to ask about the EGR valve as I saw online this can cause this type of problem. Where is it located and is it worth removing as i saw mentioned its a common area for problems?

Thank you for any help!
 
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