Any Ideas

[Miket]

I'm having a problem with my chevy cutting out, after I leave the car in the garage overnight, the following day it starts first push on the starter, but after about 1/2 mile the engine stops dead, I try to start it and it turns over but will not fire, if I leave it for about 5 mins it fires up and will run all day without stopping again. It was suggested that the cold weather was freezing the carb, so I tried starting it in the garage and let it get up to working temp, but it still cuts out on tick over, then same again it will run all day. If I leave the car parked for a couple of hours it still fires and runs perfect.

Iv'e checked the fuel filters, pump and all electrical connections and everything seems fine.

It only seems to have started when I installed a dehumidifier in the garage, could it just be a coincidence?

Help please x( x( x( x( x(

[wilf]

Mike - it can only be one of two things, an intermittent fault with either spark or fuel.

Only way to find out is to check them both when it is "non-running" mode. Pull a spark lead and use a spare plug to see if there is spark, if there is and it's good and fat, then it must be down to fuel.
My money would be on a fualt in the igintion system somewhere which only exhibits itself at a certain temperature.

And anyway, its a Chebby, whaddya expect? }(

[Miket]

Wilf

Iv'e got an MSD 6AL unit, do you think it could be a fault in this?
the Chebby's alright, its all the bits that are fastened to it that are giving problems.

[wilf]

Mike, before you worry about the MSD unit (which of course, could turn out to be the culprit), I would be looking for sneaky, hard to find intermittent connections in the ignition circuit, from the feed to the ignition switch right throught to the HT system.
Could be that the lower temps are making one show up. Could be anywhere, from a poor fuse blade contact to a bad HT lead connection.
Only good diagnosis when it is in fault mode can find it.

As someone once said, most electrical faults are "mechanical".

First, of course, you have to establish that is a spark problem, not fuel.

[Miket]

Wilf

Thanks, looks like its going to be a pig of a job.

[maxGD059]

Mike

You have my sympathies. All I can say is completely rule out an electrical problem first as they are most common cause. I thought I had done this when I embarked upon complete rebuild of the SU's my Rover was running on at the time, only to find I had an intermittantly duff ballast resistor, some time (& expense) later.

Cheers

Richard
(It'll only be a 5 minute job)

[SimonP]

Check for condensation inside the distributor cap.
I've had problems like that on a Vauxhall when an aftermarket cap was used. However that was after about 15 mins running.
Worth a look.

Simon.

[Neil O]

Hi Mike, I had the exact same problem on a (sorry can't say, too embarassing) and it turned out to be a hairline crack in the dizzy cap. It only showed up when at a certain temp, and could not be seen by the naked eye. I only found it was this after changing all plugs, leads, points etc.
Cheers,
Neil.

[Miket]

Neil

Thanks for the valid advice, but mines the opposite way round, when it gets warm in will run all day.

It cuts out once about 5 mins after starting, then its ok for the rest of the day.

Soon be the big day, looking forward to seeing the new toy at the next meet.

[Miket]

Thanks everybody for the advice,

I have found the problem, it was the centre connector in the distributor cap from the coil, the spring must have been sticking and not making contact with the rotor arm at certain temperatures.

Wilf was correct all electrical problems are mechanical and thanks to Neil for pointing me in the direction of the dizzy.

:7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7 :7