Hi all. Firstly, I will apologise in advance for my lack of knowledge regarding what parts are officially called! So, I have a 1700 type 4 engine in my bus..runs like a dream, however recently developed an issue where it cuts out at lights, etc. And will not tick over..the engine speed just drops too much & it won't stay running. The bus has been ok for the last year since I bought the bus, but this has only recently started happening. Just changed the plugs..they all look good. Changed dizzy cap. Got electronic ignition (pertronics). Couple of things I thought of..I remember on wheeler dealers when they did the trekker that edd replaced a damper that the throttle rods rest against..could this be faulty? How do I test it? There is no resistance behind my pushrod. Also, where the little flaps that sit at the end of the throttle pushrods and rest against each carb close straight against the carburettor body..there are little threaded holes that look like they have adjustment screws to tweak the throttle stops but my holes have no screws in them. Any ideas?
This is the damper I am talking about, on the left side of the picture, although the picture is actually rotated through 90 degrees, so the camper is actually on the top. I have standard solex carbs, fully rebuilt. The screws I am on about rest against those s shaped brass coloured brackets on the right of my picture, actually at the top as the photo is rotated. Hope this all makes sense.
Have the wires come off your cutoff solenoids? Does it/they work? Classic symptom: engine runs fine, but dies at idle.
This is how the spark plugs look. One other thing...when I was driving home at the weekend, pulled fine but just feathering the throttle when not under load it felt a tiny bit jerky, not as smooth as usual. Could it be fuel starvation? Filter looks clean, got facet electric pump, both under the bus..can't see a regulator? Pulled a plug off the solenoid and it cut out so they look to be working ok?
Plug colour looks fine. However I suspect you may have developed an air leak. Check your servo hose & carb balance pipe hoses for cracks. The rubber elbows which fit to the tappings on the manifolds are particularly prone.
Thanks Gooders..Will take look..air pipes in the engine bay look in really good condition. Will I need to check under the bus from front to back to check the servo hose?
You could disconnect the hose at the engine side & blank off the pipe to rule it out. Don’t forget to reconnect it before driving the bus
Sorry to appear dim Gooders , but could you explain exactly what I need to do..in idiot speak. Like which pipe do i need to remove & which one blanked off & what am I looking for?
No..carbs were rebuilt years ago..it's run spot on for the last 18 months since I've owned it. Really weird..all the pipes and tubes in the engine compartment look brand new. Just taken the wires off all 3 solenoid and they click with the ignition on, so they look ok. Fuel filter looks clean. Fuel pump is clicking with ignition on. Could it be crap in the carbs, or something has gone out of kilter? Didn't want to mess too much as it usually runs sweet as. Thought about running some redex through the carbs & if that doesn't work for the missing throttle stop screws on each carb & increase the tickover speed with these?
Under the carbs you have a pedestal at the bottom of the pedestal have a look to see if the little rubber elbow has split it fallen off
Mine is FI and used to die occasionally at lights / when I stopped at junctions and I found that my air pipes were split but I only noticed it when I took them off and squeezed them and the cracks then showed. So while you are carbs, my first suggestion to start at would be to check all pipes and tubes for cracks.
Check the pipes for cracking - the balance pipe that runs round the back of the engine bay has two rubber 90 degree elbows which are prone to splitting. You can try and spray a bit of WD on them to see if that impoves the idle momentarily. The throttle stop thing you refer to is a dashpot and is designed to stop the sudden snap of a closed throttle from stalling the engine ( I believe) many run with out it and I doubt it would cause an issue (try pulling up and lifting slowly off the peddle to put your mind at rest)
If you have either too much air or too much fuel at low engine load it will stall. A slight leak from one of the carburettor fuel metering valves may make it too rich at idle, while at higher engine loads, the fuel demand of the engine exceeds the rate of the leak, the plugs then show cleaner because at high revs there is no problem.. The hint there is the slight hesitation as you back off the throttle. ..e.g.driving on a level road
But its always run so well, so something has changed. Had a play after work tonight. Took the elbows off the manifolds, put some rubber tube on the manifold tubes and blanked off the other end .still stalling, so sounds like the servo pipe isn't the issue. Put some redex down the carbs..no change. Took the oil bath air cleaner off and checked the carb balance pipes..all good as new. Fudged it by turning the throttle stop screws a little so at least I can run it without it stalling. Took it for a spin and it's really hesitating now when not under load, so something not right. Noticed that the rev counter , which runs off a lead to the coil, is fluctuating up and down, so could there be an issue with the coil..or the pertronix electronic ignition module playing up?
So..replaced the coil with a flamethrower one..brand new..still no change... This is really sapping my enthusiasm now..any more suggestions..PLEASE..Could the pertronix ignitor could have gone 'bad??
I would suggest dizzy as you've changed the cap, check firing order first off, then you are into the internals if not that, condenser etc (they have been known to fail often). Is it timed correctly since the change?
Ours did but symptoms were a bit more will run /wont run than poor idling. Sent from my SM-T580 using Tapatalk
