Technical 1301cc wont start

[unowho]

After a rebuild engine ran fine for 50kms then started to run rough for a bit and now wont start unless with full throttle and even then wont run well. Have checked cleaned and rechecked everything and can only think of the problem being the "Idle cut out device" malfunctioning on the carby. Any suggestions???

Carb gets fuel, has good spark. Timing is sweet. New rings and bearings, seals and gaskets, Cylinder hone (just to clean them up) head shave, valve grind. took a bit to get it running initially and apparently had this problem before rebuild. :bang:

 

[Chas Uno]

Your problem could be many things though I suspect a fuel related issue. Try and start the engine again, then check the plugs. If they're wet/ black then then engine is running rich and might be flooding (you should be able to smell this too). If they're dry then you have a possible blockage in the carburettor or the petrol tank breather is blocked. If they're black and oily then you have oil getting into the combustion chamber. All these can cause or be the result of the symptoms you describe.

It's very much a process of elimination, so start with the fuel system and see what you can find. Good luck

 

[unowho]

Thanks for that. While waiting for a reply I scanned through screeds of forum Q&A's in the uno forum and discovered that the most likely problem is with the Idle cut off solinoid at the back of the carby. Plugs are good (new) and sparking well, so I'm sure the finned thingy on the side of the dizzy is okey dokey, tho' I could be wrong. I will connect Idle cut off solinoid to orange wire and see what happens..it may well be the controller for this on the blink or the unit itself. Prior to this (after the initial annoyance of getting it started) engine ran sweet..heaps of grunt and no irregular noises or runnig problems. Will try a few things I picked up on in the forum and let you know what happens. Thanks again

 

[jjhepburn]

It sounds like a blocked jet in the carb. Might be worth pulling the carb apart and giving it a really good clean with compressed air and carb cleaner.

I've never heard of that solenoid giving problems before and I think its in the normally open position.

I got a speeding ticket once because of a blocked jet!!! Car only ran on full throttle and it was late and I wanted to get home from work. I drove home with bursts of full throttle and idling, unfortunately a cop came over a crest when I was in full throttle mode!!! 91 in an 80 zone!!! :bang:

 

[unowho]

That sux. Cops always arrive when they are needed the least.

Any ways FCO Solinoid not the issue. Was running sweet for 50ks then started to run rough as I was comming home, got in the driveway and parked,it idled rough then I switched it off. Next morning no go. Tho It did try to run with throttle wide open but never really caught properly. Spark is fine on ALL leads and plugs and it does appear to be pumping fuel into the carby throats. Carb jets have had TWO good cleans. Have checked everything that has vacmume did notice brake servo was making a funning vibration as I sucked in that and does not "hold" vacume...dunno if thats normal or not and econometer unit seems to work fine. Vacume advance holds vacume too.

So...I'm kinda all outa ideas. Mite drop the guys at Dino enterprises a line. See if they have any ideas. Gee. Must be handy for you living so close to them huh?

 

[unowho]

Got it sorted

turns out the sparkplugs became "Fuel Fouled" a nasty coating on the sparkplug tips that makes them spark ERATICALLY and not ignite the fuel. The cause is a way too rich fuel mixture.

 

[jjhepburn]

Hmmm could be the wrong spark plugs...

The book says to use BP7ES (NGK, not sure of other brands) but I found that my car started mis-firing and was very hard to start (particularly after hard driving). The plugs were fouling really bad and I needed to clean them regularly.

My car now has BP5ES which are a hotter plug and I have had no problems since...

My car is used for motorsport hence the BP5ES, you might be best with BP6ES?.?.

 

[unowho]

Yup. Using the BP6ES NGK's I figured the fouling may have somthing to do wth mixture. Lo and behold the tamperproof plug was missing and the mixture screw was practically wound right out!! Never can be too sure was previous people have done to your car eh?

Seems to run fine now. Peppy little motors man....love 'em.