Quick intro and heat issues!!

[Calclark320]

Evening all, 

Firstly just wanted to introduce myself and say a thank you to all the advice I have 'borrowed' off the site over the last few months. In short, I was lucky enough to inherit my fathers 63 TR4 that he has had since 68(I think he drove about 1400 miles in 30 yrs). To give you a quick tech aspect, I've put in a lumenition electronic ignition, new timing chain, done the timing, gaps, changed endless gaskets, fluids and tuned (ZS 175CDs). I think i've eventually got it leak free(for now) but there are two aspects I can't get my head round and was hoping to ask for some advice. 

1. It runs great until about an hour of running, then the running gets very lumpy(almost as if its running super rich-which its not). If I am very gentle with the throttle it runs through the rev range fine but any quick throttle responses causes 'coughing'. I'm assuming its the carbs getting hot from the forum but wondered if anyone has experienced this and also found a solution that keeps the car fairly standard. It has not had any updates regarding unleaded running, and has the standard exhaust system. I'm sure you've heard it before but would a exhaust wrap work or reduce this?

2. Leads a little bit on from the previous post - is it worth upgrading the to the unleaded head conversion? The car isn't planned to be raced, driven hard and run as a weekend smile/tear producer! 

 

Thanks to all and hope you're having a good weekend,

 

Cal

[RogerH]

Hi Cal,

regarding the head - I would leave it alone. Check the tappet gaps every month or so. It could last many years

 

As you say something getting too hot.  What plugs do you use. ?

Could be the coil getting hot or in fact any of the ignition components. If you start changing things do so but one item at a time then run. otherwise you will not know the answer.

Don;t bother with the wrap until you identify the problem

Also - welcome to the forum.

 

Roger

[Calclark320]

Hi Roger - many thanks for the quick reply. Using NGK BP6HS plugs. I'll try move the coil off the engine mount to the arch and test. I'm guessing the carbs aren't the issue hopefully. 

All the best,

 

[Steves_TR6]

My vote goes to coil, overheating and breaking down.

as they’re cheap this may be worth trying, or i have a spare if you’re wanting to try before buying Cal

i’m in Chertsey

steve

[John Morrison]

Welcome Cal.

I too vote for the coil being your issue, and moving to the wheelarch

will help, personally I carry a spare mounted there, so in the event of an issue, switching

the cables and king lead takes seconds.

[Calclark320]

Thanks so much for your reply gents - I'll focus on that for now and hope it solves it.

Steve - that's a very kind offer but I'll get another one as it seems its a must so having a spare can't hurt.
John - thanks for the pic. I'll keep that in mind for future peace of mind.
 

All the best,
Cal

[RogerH]

Hi John,

do you normally have a blanking cap over the coil output hole.  If not it may be worth doing.

 

Riger

[ianc]

It's possible that the petrol tank has shed small particles of rust and that these have been carried into the glass bowl of the petrol pump.  When the engine is working hard, the increased fuel flow can carry the particles upward and they block the gauze filter, causing the engine to lose power and, possibly, stall.  Have a look at the galss bowl and see if there's a lot of stuff in the bottom - if so, clean it out, but the problem will recur as once the tank starts shedding, it will continue!

My article in Section K3 of the Technicalities CD describes the problem and the sloshing treatment of the tank, which solved the problem for me 21 years ago.

Ian Cornish

[BlueTR3A-5EKT]

I had a Volvo 240 that ran nicely until hot then would be a pile of poo.  That turned out to be a split diaphragm in the carb ( same type of carb as you have Cal.)  So worth a quick check.

On the coil - be sure to get the low tension wires correctly connected.  If your car is negative earth the  -  terminal of the coil is connected to the distributor.  For positive earth it is the opposite. ie + terminal to coil.  

See what Lumenition say for your set up    This swapping will affect hot running of the car with standard coil and ignition system.

Cheers

Peter W

Edited August 5, 2019 by BlueTR3A-5EKT

[tim hunt]

I'm intrigued John. If you think the coil mounted on the side of the block is in rather too hot an environment, as do I, why is yours still there? Mine is on the bulkhead, below the wiper motor and, as belt and braces a spare is mounted on the wheel arch for immediate use if ever required.

Tim 

[Calclark320]

Hi gents,

Ian - Funny you say that as last night I took the fuel pump off and noticed a large amount of flake in the filter. I've cleaned it all out and also added an extra extra filter up stream to hopefully knock that on the head. I'll review your article and get it on the never ending list of 'things to do!'

Peter - thanks for the info. I've rebuilt the carbs and the diaphragms look good so i don't think its that. I'll certainly check the coil set up as it is running neg earth so that could definitely be the issue. I've also just ordered a replacement coil from Distributor Doctor (a great help) which hopefully will narrow down the cause.

Thanks all - To be continued......

[John Morrison]

21 hours ago, RogerH said:

Hi John,

do you normally have a blanking cap over the coil output hole.  If not it may be worth doing.

 

Riger

Roger, no, so thanks I'll cut up a Marigold or something.

John.