Hot start mod Installed and now having start problem

[farrowby]

Hi all,

I have just recently installed a hot start kit, the one which is under bonnet rather than in the footwell wiring, and it appears to be causing a hot start problem !! The kit consists of a relay powered from the alternator in line with the start motor solenoid... how it works god only knows, i guess it takes power from the alternator to engage the starter motor, never been too hot on sparks. I also installed the 2 stage fan at the same time taking power from the starter motor to run the fans after the engine has stopped. Anyhow after a run when the car is nice and hot go to restart and all i get is the solenoid clicking and all dash lights/electrics flashing with the clicks, after a while when the car has cooled she fires up ok.

Any ideas, have I done something stupendously stupid as usual ?

tia

Tim

Edited by farrowby on Sunday 29th July 11:25

[David Beer]

I agree with Andy, check connections, pos or neg. Anything you have added could not of caused problems, they are improvements !

[tvr4ever]

Yep, my thoughts exactly, must be loose connnection.
Example: Last saterday, coming back from a trackday at Zandvoort, the engine temps were a bit higher than normal.... ? I check the fuse in the 2 speed fancontrol, intact !! Turns out that one of the fanconnectors came loose and was just dangling there. Reconnected it (secured with little tie rap), and Davids little electronic marvel brought back the temps to it's normal operating temperature.
David, once again, you are the man.

Edited by tvr4ever on Sunday 29th July 10:17

[farrowby]

Will check the conections later if I get a chance. I didnt install the mods my self, I got my local garage to do them as the car was in for some other work so may well have not done it properly, already found a exhaust mounting bolt which they didnt tighten up.

On reflection my headding was a bit missleading as I know its not the kit that was the problem!! sorry if it cause any offence David, none was ment. Will edit it if I can.

[crackedfinger]

I think the classic hot start problem is more about the solinoid sticking, if you hear the clonk then that is less likley to be the problem. I am in the same boat right now, got a clonk but it really struggles to turn over, just got it started today with a better that should of been OK, a jump starter and a 180amp boost starter all connected together on the battery terminals. I reckon it is an earthing of the battery somewhere, maybe the same problem for you?

[farrowby]

Ok, had a look around under the car at the wiring, didn’t look like that there was a problem there, but while it was up i decided to remove the hot start mod to try and isolate the problem. Went for small run but while returning home up the A1 the cabin started to fill with smoke... eeeekks I thought and pulled in, got my son out the car just in-case it was a fire etc, called the misses out she came over and got the boy, opened the bonnet and no sign of any damage or petrol smell, started her up all ok, couldn’t see any signs of where the smoke came from, I am guessing that it was exhaust fumes, prob a manifold gasket, but what worries me a little is I cant see any leek/smoke when running her in the garage, anything else it could be ? Will have to take a look when shes cooled down to see if I can find the problem in the hot start wiring.

[spend]

I'm a great supporter of a battery cut out & fire ext. in these cars (prob any fg car TBH).

Dave

[bigdods]

Could be a knackered battery. I had been having the kind of problems you describe for a while. On doing lots of testing I found that the following happened:

1. on starting from cold just a click from the solenoid. after 4 or 5 goes of this clicking it would eventually turn over and start normally (if a little sluggish).
2. Starting from warm after a short run, no problem everything fine
3. Starting from hot after a long run - not even a click !

Tried the hot start kit, improved it a bit but not much.
Had a new starter fitted, again this improved things but didnt solve the problem
New battery fitted, problem solved.

I *think* (and I am no sparks!) what happens is that on a knackered cell when the battery warms up the plates move and short. This explains my inability to start when hot. I suspect that the plates when cold were bending too far apart and causing reduced amps hence cold start problem. I guess after a couple of goes the battery warmed up a bit and I got more amps. Who knows.

Try a new battery

[farrowby]

Had a new battrey fitted when I had the rear end smash in Feb so I dont think its that but could be. Worth getting it tested I guess. The car is showing a charge rate of around 14.5 v on the dash unloaded, which drops to around 13v with load, when fully loaded with lights and full fans it gos down to around 11.5v ish.