1971 LT1 TI Ignition System--Won't Start

[Paul C.]

My 71 LT1 will not start. There is what appears to be a weak intermittent spark when trying to start. Replaced all the plugs, ignition wires, rotor, dist cap. Have ordered a TI coil. Seems to be sufficient spark at end of coil wire but not enough spark during starting to trigger timing light. Carb rebuilt by Jerry MacNeish and TI system rebuilt by Dave Fielder 3 years ago (700 miles). Getting gas. Any suggestions on how proceed or check out system????? Car has been getting harder to start--thought it was getting to much gas--jets backed out 1.5 turns.
Thanks Paul

[Ken K.]

Re: 1971 LT1 TI Ignition System--Won't Start

How is the coil?

[Paul C.]

Re: 1971 LT1 TI Ignition System--Won't Start

I ordered a new TI coil because it was the only thing I haven't replaced. Not sure how to check it out.

[Dave S.]

Re: 1971 LT1 TI Ignition System--Won't Start

I ordered a new TI coil because it was the only thing I haven't replaced. Not sure how to check it out.

Paul,
Did Dave replace the pole piece when he did your distributor. ???? My experience indicates that that can cause intermittent spark issues and maybe more. Could be the coil but they often work when cold and quit when they get hot. Be aware that the new coils are offshore made and do not match the impedience of original "272" coils. The car may run but it may not run properly. If you think its the coil it may be worth troubleshooting it with a Delco "207" service TI coil. Maybe another trip to Fiedler will be needed.

[Paul O.]

Re: 1971 LT1 TI Ignition System--Won't Start

Paul

I agree with Dave's comment I would check out the magnetic pole piece that is where most intermittent problems occur the green and white small wires break due the flexing from the the advance plate. I would also check Dave Fiedler's web site he has a very good troubleshooting flow chart that will help you narrow the problem area.


Paul 18046

[Terry M.]

Re: 1971 LT1 TI Ignition System--Won't Start

There is also a TI troubleshooting flow chart in the Chevrolet Service Manual for those years where TI was available. I have not compared Dave's chart to the Chevrolet chart, but using either would be a lot better than throwing parts at the problem -- and a whole lot less expensive.

[Clem Z.]

Re: 1971 LT1 TI Ignition System--Won't Start

My 71 LT1 will not start. There is what appears to be a weak intermittent spark when trying to start. Replaced all the plugs, ignition wires, rotor, dist cap. Have ordered a TI coil. Seems to be sufficient spark at end of coil wire but not enough spark during starting to trigger timing light. Carb rebuilt by Jerry MacNeish and TI system rebuilt by Dave Fielder 3 years ago (700 miles). Getting gas. Any suggestions on how proceed or check out system????? Car has been getting harder to start--thought it was getting to much gas--jets backed out 1.5 turns.
Thanks Paul

check the ground wire connection at the "black box".

[Paul C.]

Re: 1971 LT1 TI Ignition System--Won't Start

As soon as Clem mentioned the ground for the amp box, I remembered having trouble when I installed the rebuilt TI system due to poor ground. Cleaned it off and the first turn it started. Thank you!! Thank you!!!

[Clem Z.]

Re: 1971 LT1 TI Ignition System--Won't Start

i have tested TI black boxes for corvette owners whose car would not start but the box was good and most of the time it was the ground.

[Paul C.]

Re: 1971 LT1 TI Ignition System--Won't Start

Unfortunately I'm back. As I said car started right up, took it out for a short run and it ran great.

Changed oil next day and went to start and it won't start again. Pulled a plug and there is a bright spark (recleaned TI amp ground just to make sure). I smell gas but the carb was just rebuilt by Jerry MacNeish.

I held the choke open, waited 12 hours, and still would not start. It never acts like it going to start--just turns over and doesn't catch. Any thoughts---nothing worse than an intermittent problem. Can't check timing since not running--but ran great.

[Timothy B.]

Re: 1971 LT1 TI Ignition System--Won't Start

Paul,

Check the grounds with a ohm meter, go to Dave Feidlers website and see if you can troubleshoot componits.

Put the old oil back in and it may be fine..

[Dave S.]

Re: 1971 LT1 TI Ignition System--Won't Start

Paul,

Check the grounds with a ohm meter, go to Dave Feidlers website and see if you can troubleshoot componits.

Put the old oil back in and it may be fine..

Paul,
I'll try again. You should check the pole piece as I mentioned above. A defective one will cause intermittent operation.

[Paul C.]

Re: 1971 LT1 TI Ignition System--Won't Start

According to Dave's website, if there is a spark there is no problem in the primary circuit.

I Have opened the butterfly valves and there was gas sitting in the bottom of the carb--don't know if that is normal. Removed all the gas from the carb and will set the adjustments very lean so it doesn't flood and see if I can get it started. I think it is flooding?? Normal is 1.5 turns out. Will it start at 3/4=1 turn out normally

Thanks Paul

[Paul C.]

Re: 1971 LT1 TI Ignition System--Won't Start

When I prop the butterflies open and clean all the visible gas out and try to start it it starts for just a second and then dies. Must be in the carb. Trying closing the jets all the way down and cleaned gas out--it starts again for just a second on the first crank and then dies. Any suggestions?

[Michael W.]

Re: 1971 LT1 TI Ignition System--Won't Start

The 'jets' you are playing with are for fine tuning at idle speed and have no effect on start/no start. Look elsewhere.

Is the accelerator pump working? Fuel pump good?