R20 rough running?

P

peabody

Member
Tadpole
Joined
Mar 5, 2003
Messages
174
Location
Melbourne
My R20 is running rough in the mid range and can have quite a flat spot on take off. Seems to be carburettion as everything else looks fine. Has anyone experienced similar problems? It is intermittent and seems to be temperature sensitive. As I am no expert on the 20/18 pollution gear setup if someone can't help I will have to go into a "learning curve" mode. Will the 25 injection head go on the 20? Will the 25 motor "slot" into the 20? All these questions and more are on my mind.
Thanks out there I really enjoy this forum.
 
peabody:
My R20 is running rough in the mid range and can have quite a flat spot on take off. Seems to be carburettion as everything else looks fine. Has anyone experienced similar problems? It is intermittent and seems to be temperature sensitive. As I am no expert on the 20/18 pollution gear setup if someone can't help I will have to go into a "learning curve" mode. Will the 25 injection head go on the 20? Will the 25 motor "slot" into the 20? All these questions and more are on my mind.
Thanks out there I really enjoy this forum.
Click to expand...
PB, I owned 2 20's over a period of about four years. Most of the rough running I experienced eventually turned out to be electrical in origin. Notably, the condenser on the distributor and the coil. Are your points looking like some mongrel has run an oxy torch over them? Plus I replaced the cap twice.

I swore black and blue that the problems were the carb....changed the carb several times, but in the end the problem would turn out to be electrical.

The other bastard on the air conditioned ones is the solenoid idle valve. If it is stuffed the car won't idle...wiring to the valve can be a problem as well (prone to internal cracking - maybe because of engine movement vibration..not sure) the result being an incredibly difficult to sus out intermittent fault.

I hope you get it sorted soon and start to enjoy owning it. I always felt like I was driving a rolly polly tank, but they are great cars.

Good luck with it.
cheers!

<small>[ 24 July 2003, 07:46 PM: Message edited by: BogMaster ]</small>
 
You should also check the internals of your breather hoses to see if the restricting valves are still in there. These can be bodgied up easy enough if they are missing. cheers!
 
Thanks BogMaster, I agree carbs are too quickly blamed for rough running its just that everything looks fine, no pitting of points and the like. The coil would break down and get worse under load but the smoothness improves as revs rise.
I will take your advice and check out all the "lines". It was interesting driving the 20 and stepping straight into a 16 the 20 probably has more go but doesn't have the "I can keep on reving" feel the 16 donk has. The lack of body roll of the 20 means it feels completely different to the 16. It will be nice to get the power steering "fixed" but never-the-less the 20 is good to drive and has a nice "cruising" feel at the speed limit or perhaps a little more he!he! Thanks again,
peabody.
 
I love the R20 it was a much underestimated car of its time? shy
 
Peabody,
Good luck witht he R20, never had a flat spot in the 3 I owned. But as of late, reading a couple of threads on here about vac advance mechanisms, if I was you I'd make sure it was Ok too.

Cruising speed in a 20??? I had my first one "cruising" at about 140+ several times, wouldn't know you were doing that speed if not for the centre line blurring into a continuos one, roll_lau Seriously they are an excellent highway car.

Cheers, Chris
 
peabody
The coil would break down and get worse under load but the smoothness improves as revs rise.
,
peabody.[/QB]
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It can happen the other way too. The 18 I had was a mongrel whenever I backed off the accelerator. It would display symptoms of fuel starvation then surging. It would jerk around corners or hop along whenever the foot was off the throttle or the throttle was being applied gently. Convinced me that the carb was dysfunctional. As I had a collection of 18 carbs at the time I started swapping them around. Several carb swaps later it was still doing the skippy. I then began replacing evry electrical item in the circuit starting with the cap, points and condenser then the HT leads...eventually a new coil fixed it.
I was lucky that I had the spares lying around the place. The coil was the only cost item.

These things can be really tricky to work out. cry

Good luck with it and let us know what the gremlin was when you find it.

cheers!
 
My 18 had an identical problem, it turned out to be the EGR valve, put a new one on, transformed the car from a dog to a pussycat. Mind you this was after replacing/farting around with everything else. Took months to track it down, and I nearly sold the car in frustration, only no-one would have bought it.
 
Well all is solved. A piece of foreign material in the primary main jet acting like a "butterfly" so sometimes it only restricted slightly other times grossly. The problem appeared to disappear on full throttle as (of course) the secondary came in and "masked" the primary.
Thanks for all your help chaps,
peabody
 
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