GT Starting issues. Can anyone explain?

adamskibx · Post by **adamskibx** » Mon Jun 25, 2007 8:55 pm

Im confused. Yesterday after working on the BX cosmetics, it failed to start, and even though there was fuel in the filter, the filter was below carb height, but below fuel pump height hence the fuel inside it. Its parked on some land where im renting a space, but on the wrong area, so I thought id better take some fuel in a can along and an external battery. Filled it up, and turned it over. It started to fire on one or two cylinders (Its over due a service, hasnt been used recently and the whether is apauling so nothing unusual there. I dried the dissy cap and leads etc, and eventually managed to get it going on all four. I kept it above 2000 RPM as you do in such extreme circumstances to keep it moving and get it all warmed up. Eventually, I disconnected the external battery and walked away to put it in the shed. The revs started to drop as they do when the auto choke kicks out, but then they dropped even more and it stopped. Now I cant get it to fire no matter what I do. I havent checked for a spark as its so wet outside, but theres not even a hint of it trying to fire. Could it be that the incomplete combustion has flooded it completely? Im a bit concerned as the MOT is soon.

Cheers, Adam

ellevie · Post by **ellevie** » Mon Jun 25, 2007 11:08 pm

That does sound a bit like a spark problem. Try cleaning the 4 spade connectors on the coil by applying a little WD40 or similar to the contacts and pushing them on and off a few times. Do the same with the connector to the ignition amplifier and also to the intermediate connector between the amp and distributor. Finally do the little connector under the metal clip on the dizzy that goes to the magnetic sensor.

Also check the short cable which connects to the sensor for good continuity. I had a poor ignition problem which I eventually traced to a high resistance of abut 10 Ohms in this cable, I bypassed the high resistance with a wire and the problem was cured.

At one time or another I have traced ignition problems to poor contact at the spade connectors or the big connector to the amp.

You can also check that the spark is strong enough by causing it to jump to a suitable earth. It should be able to jump at least 1 centimeter corresponding to about 30kV. I recently checked the spark on my TRS and it was able to jump over 2 centimeters.

mnde · Post by **mnde** » Tue Jun 26, 2007 11:39 am

All sounds very familiar! Good luck with getting it going Adam.

Mark.

adamskibx · Post by **adamskibx** » Tue Jun 26, 2007 12:49 pm

Cheers for the tips ellevie. Did you get your sorted Mark? My concern is the condition of the wiring generally. I noticed the two wires going into the little plastic thing on top of the dissy were bare where they go in so could have been shorting, but they no longer are as I have separated them. These are the electromagnetic pick-up signal wires. Ill have another look tonight and take a spark plug to a ht lead and see if its sparking.

ellevie · Post by **ellevie** » Wed Jun 27, 2007 8:34 am

This is the short cable that connects to the magnetic sensor on my 19TRS. As you can see the small connector is a moulded single piece connector. Could you possibly post a photo of the sensor connector on your GT as it appears to be different from the TRS. You can see the two wires I used to bypass the high resistance fault.

adamskibx · Post by **adamskibx** » Wed Jun 27, 2007 11:15 am

Thanks ellevie. Great pictures, but oddly it started instantly when I went back to it yesterday! However, thats not to say things are going well

My fixed bonnet blew off in the extreme winds we had and cracked my filler repair, and the oil leak is severe, and not where I thought it was coming from (or at least somewhere else too). I love this BX but that blimmin engine I got from the TRS that was free has been a nightmare from day one. I suppose I'm just rubbish at fixing oil leaks..

ken newbold · Post by **ken newbold** » Wed Jun 27, 2007 5:52 pm

I dunno. oil leaks are one of the worst things to cure. IMHO

ellevie · Post by **ellevie** » Wed Jun 27, 2007 7:10 pm

I hope you weren't driving it when the bonnet blew off --- that would be pretty scary !

If you get a chance sometime can you post a pic of the connector --- I'm just curious about what it looks like.