Hot running issue on Reliant Scimitar 6a
Discussion
Madfox said:
It runs really well, but after 30 mins in traffic starts idling rough and them needs lots of revs to keep it going. Stalled a few times but starts ok again. It's fitted with a weber carb and electronic ignition. Anything else that would help?
Starts immediately or needs a bit of churning? What's the fuel pump on it, and where?Is there an inline filter you can see?
Manual or automatic choke?
If manual, what happens if you pull it out a bit?
Have you actually given it a basic service yet?
Idle speed?
What's the temp gauge doing?
Electric fan? Working?
Any fluid loss?
TooMany2cvs said:
Starts immediately or needs a bit of churning? What's the fuel pump on it, and where?
Is there an inline filter you can see?
Manual or automatic choke?
If manual, what happens if you pull it out a bit?
Have you actually given it a basic service yet?
Idle speed?
What's the temp gauge doing?
Electric fan? Working?
Any fluid loss?
Starts pretty quickly, little churningIs there an inline filter you can see?
Manual or automatic choke?
If manual, what happens if you pull it out a bit?
Have you actually given it a basic service yet?
Idle speed?
What's the temp gauge doing?
Electric fan? Working?
Any fluid loss?
No inline filter I can see
Manual choke, haven't pulled it out when experiencing this issue
No, not done a basic service. I think it's been a while that ignition consumables have been attended to
idle speed is about 800 rpm
Temp stays solid - head gaskets are fine; were changed less than 10,000 miles ago (about 6 years)
Electric fan is working; it works off a thermostat and has a manual override which I kept switched on today
no fluid loss. Engine is tight as a drum
Madfox said:
No inline filter I can see
Double-check, but get one in.Madfox said:
Manual choke, haven't pulled it out when experiencing this issue
Might be worth a try - if it's starving itself of fuel somehow, richening it up might smooth it out.Madfox said:
No, not done a basic service. I think it's been a while that ignition consumables have been attended to
Get on it!It's fuel vaporisation 
.
I had a couple of Montego 1.6s (SU carbs not Webers though) whose running was like your Scimitar's after 30 minutes in traffic then got worse and worse if the traffic stayed bad until the things stopped running and wouldn't restart at all - several litres of cold water over the carb (and rocker cover-mounted fuel pump) got them running again - but only temporarily if the traffic didn't ease
.
I also have an MG Maestro 1600 with twin Weber 40DCNFs which runs like a pup in traffic - but it's never done what the Montego above did and thrown the towel in completely in traffic, and it's never needed the "water over the carbs and fuel pump" trick.
Then there is my 309 1600 with single Weber, that gets a bit "hot and bothered" but thankfully the carb has coolant running through it so the engine gets to a certain stage of rough-running (certainly not as bad as the Scimitar, and much better than the MG) - and then stays there
.
What fuel are you using in it?
And - more importantly - have you filled up in the last 3 weeks ("summer grade" petrol, which is less volatile than the "winter" stuff, is available from May 15th to Sept 30th every year as a general rule in the UK)?
. I had a couple of Montego 1.6s (SU carbs not Webers though) whose running was like your Scimitar's after 30 minutes in traffic then got worse and worse if the traffic stayed bad until the things stopped running and wouldn't restart at all - several litres of cold water over the carb (and rocker cover-mounted fuel pump) got them running again - but only temporarily if the traffic didn't ease
.I also have an MG Maestro 1600 with twin Weber 40DCNFs which runs like a pup in traffic - but it's never done what the Montego above did and thrown the towel in completely in traffic, and it's never needed the "water over the carbs and fuel pump" trick.
Then there is my 309 1600 with single Weber, that gets a bit "hot and bothered" but thankfully the carb has coolant running through it so the engine gets to a certain stage of rough-running (certainly not as bad as the Scimitar, and much better than the MG) - and then stays there
.What fuel are you using in it?
And - more importantly - have you filled up in the last 3 weeks ("summer grade" petrol, which is less volatile than the "winter" stuff, is available from May 15th to Sept 30th every year as a general rule in the UK)?
It's your ignition coil
It's overheating after a period of driving. Either replace it for an instant fix, or pour cold water over the overheated coil.
But it could be anything, and all these "ideas" on an internet forum are just ideas. Do some straightforward fault-finding and report back when you've found the problem.
It's overheating after a period of driving. Either replace it for an instant fix, or pour cold water over the overheated coil.
But it could be anything, and all these "ideas" on an internet forum are just ideas. Do some straightforward fault-finding and report back when you've found the problem.
Madfox said:
Starts pretty quickly, little churning
No inline filter I can see
Manual choke, haven't pulled it out when experiencing this issue
No, not done a basic service. I think it's been a while that ignition consumables have been attended to
idle speed is about 800 rpm
Temp stays solid - head gaskets are fine; were changed less than 10,000 miles ago (about 6 years)
Electric fan is working; it works off a thermostat and has a manual override which I kept switched on today
no fluid loss. Engine is tight as a drum
Does it have a K&N air filter housing or a Ford pan filter? Some owners have had rough running issues with K&N. No inline filter I can see
Manual choke, haven't pulled it out when experiencing this issue
No, not done a basic service. I think it's been a while that ignition consumables have been attended to
idle speed is about 800 rpm
Temp stays solid - head gaskets are fine; were changed less than 10,000 miles ago (about 6 years)
Electric fan is working; it works off a thermostat and has a manual override which I kept switched on today
no fluid loss. Engine is tight as a drum
Hamish Finn said:
It's your ignition coil
It's overheating after a period of driving. Either replace it for an instant fix, or pour cold water over the overheated coil.
But it could be anything, and all these "ideas" on an internet forum are just ideas. Do some straightforward fault-finding and report back when you've found the problem.
I'll second this. I had exactly the same problem on the '72 Corvette I used to own. I tried all sorts to stop the fuel vaporising as several people had said that was the problem. But it turned out to be the coil: It was sited above the inlet manifold and was fine during normal driving, but if I was in stop/start traffic for an extended period - around 30 mintes - it would slowly start to break down because there was not enough airflow to keep it cool. This showed up as the engine starting to run rough and getting steadily worse until it would stall completely. After a period to let it cool it would run fine again. Once I replaced the coil it was perfect.It's overheating after a period of driving. Either replace it for an instant fix, or pour cold water over the overheated coil.
But it could be anything, and all these "ideas" on an internet forum are just ideas. Do some straightforward fault-finding and report back when you've found the problem.
Have you tried the RSSOC forums? Scimitars have a number of common issues & it would be a good place to ask.
http://www.scimitarweb.co.uk/index.php
http://www.scimitarweb.co.uk/index.php
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