Non / Intermitent starting help

[GMCVANN]

Hi All
I need a few suggestions to get my ty running for my up coming wedding.
About my ty...
It has been sat for the last 5 years, with me starting it from time to time & was running fine when I put it away (apart from alternator which I had fixed).
Over the last couple of years it had become intermittent with starting which I had just brushed off as a duff battery which was dying, at the end of last year I brought a Optima & thought my probs would be solved, but it wouldn't start & just turned over. I left it a couple of months (on a optimate trickle charger) & tried again & it fired right up on first attempt & it has been like this on & off over the last 6 months.
So with my wedding coming up & wanting to drive it on the day I started looking into why it was playing up.
So far I have put on a new set of 8mm Taylor wires, new Conrad cap & rotor, new standard ignition module & new standard ignition coil non of which seem to of solved my problem. I checked for spark with a new plug earthed to chassis & with a plug wire first to the cap then straight from the coil, both occasions I appear to have no spark.
I have an aftermarket alarm / immobiliser (Clifford concept 300) fitted professionally approx. 12 years ago which seems to function as it should, a few days ago I put the alarm in valet mode to override it & the truck started right up again & ran as smooth as it ever did & thought I had my solution. next day I went to take my Ty for an MOT (UK road worthiness test) & couldn't get it to start again even with the alarm in valet!
Today I had the guy who installed the alarm all those years ago over to check it out & has said the alarm is fine & that it doesn't cut spark anyway (he didn't charge me either so tending to believe him).
What have I got left to check?
Any help appreciated.
Thanks
Gmcvann
Ty1570 UK

 

[Jimmy]

Re: Non / Intermitent starting help

Purple wire and shit starter.

 

[wildphil]

Re: Non / Intermitent starting help

If you are not getting spark from the coil. Could be a bad coil. Also I think the ignition module could cause that. Do you have power to the coil when the key is in the on position and engine not running?

 

[Don W.]

Re: Non / Intermitent starting help

Purple wire and shit starter.

Not if it's cranking and just not starting.

I have personally had one of these coils fail. Not on a SyTy and it failed completely, not intermittently. To me your description indicated ignition. BUT it could be a bad fuel pump. Works one time and not the next. The test wire is near the dist. Jump it with 12v and see if the pump runs. Or on the times when it doesn't start do you hear the pump run?

Since ign modules are much easier to change, and less money, than fuel pumps throw one of those at it and see what happens.:squint:

Intermittent issues are a pain. Good luck.

HTH

 

[GMCVANN]

Re: Non / Intermitent starting help

Purple wire and shit starter.

The starter is turning fine (hot shot realay'd it a while ago).

 

[GMCVANN]

Re: Non / Intermitent starting help

Not if it's cranking and just not starting.

I have personally had one of these coils fail. Not on a SyTy and it failed completely, not intermittently. To me your description indicated ignition. BUT it could be a bad fuel pump. Works one time and not the next. The test wire is near the dist. Jump it with 12v and see if the pump runs. Or on the times when it doesn't start do you hear the pump run?

Since ign modules are much easier to change, and less money, than fuel pumps throw one of those at it and see what happens.:squint:

Intermittent issues are a pain. Good luck.

HTH

I have a brand new coil, ignition module, cap , rotor & leads all went in over the last few weeks.
The fuel pump I can hear & comes on with the ignition, fuel presure gauge shows 45 which it has always ran well on (i think I tee'd off the fuel line under the truck).
Had some old fuel in the tank but have since added to it.
Im still thinking more ignition as when it ran the other day it ran for a good 45mins no stumble or anything.
Thanks for replys.

 

[GMCVANN]

Re: Non / Intermitent starting help

I don't see a distributor pick up coil (the thing with the green and white wires that plugs into the module) in that list. The pick up coil is fussy to change, but does go bad, and can cause an intermittent no-spark. They are easy to check with a VOM. 500-1,500 Ohms, unchanging value. IIRC, in the 800's is normal. They take about an hour to change.

Hi is this the part you are meaning ? http://www.summitracing.com/parts/smp-lx342/overview/make/gmc/model/typhoon
Thanks

 

[Don W.]

Re: Non / Intermitent starting help

I don't see a distributor pick up coil (the thing with the green and white wires that plugs into the module) in that list. The pick up coil is fussy to change, but does go bad, and can cause an intermittent no-spark. They are easy to check with a VOM. 500-1,500 Ohms, unchanging value. IIRC, in the 800's is normal. They take about an hour to change.

I never attempted that change but I've looked at it. Is that part even available? Would he be better off just buying a rebuilt dist? Just wondering...

 

[Aaron Staub]

Re: Non / Intermitent starting help

Always comes back to the old fuel/air/spark combination. If the truck has sat enough you could have some fouled injector paths that are keeping the mixture too lean. I'd pull the intake hose off and give it a good shot of ether and see if it will catch for a few seconds. If it does, its almost certainly a fuel problem. If it still doesn't try to fire, I'd be double checking ignition timing and compression.