General TR TR4A Engine Won't Start

[Tr-Beg]

With a erratic electrical problem you will have a sudden shut of the motor even while running. For Hs6 I like to remove the dashpot and piston and look at the jet. Sometime you can see a flood of fuel in the carbs ( the level is too high in the bowl and the fuel run out the jet ) Normally the fuel must be round 2 mm under the top of the jet, you can see at this time if the 2 jets are at the same level. If it's ok I check then the level in the bowls.

 

[CJD]

Still sounds like classic vapor lock to me.

 

[KVH]

After all kinds of tests and checks, I replaced my fuel filter and everything seems perfect. If that was the problem, I sure have to wonder if fuel filters should be left off. British Leyland didn't use them to my knowledge. I checked my old filter and can't see much other than a "ratty" look. I blew into the input end and it "popped" the fuel out. That seemed odd, but who knows. Anyway, after fifteen starts and stops, I have no issues now. Thanks for the ideas and help from all here.

 

[dklawson]

I still prefer to have a fine, translucent, paper element filter after the pump and before the carbs. On some of my cars I also fitted a coarse, cloth mesh filter between the tank and the pump inlet (Spectre brand or similar glass body, metal end cap filter). You don't want to use a fine element filter on the suction side of the pump... they can quickly load up so little or no fuel is pumped to the carbs.

 

[KVH]

Flopped on start again. It's got to be the pump or a clog at the tank. I'll disconnect the line and report back. Even if I'm destined to be the only one to learn anything from this.

 

[KVH]

Tank and pump are fine. I'm sort of lost. Car runs so great, then won't restart after sitting until it sits longer and cools. If I restart immediately after stop, I'll start right up. It's after sitting for 20 minutes or so that it won't restart. Another 30 minutes is needed, and then it finally fires up. I'll figure this out--somehow.

 

[TR4nut]

I agree with John- it sounds like vapor lock. Gasoline can boil slowly after you shutdown from engine or exhaust pipe heat. It won't happen immediately but takes a few minutes.

 

[Popeye]

I am far from an expert, but found the following article helpful in explaining vapor lock - and what to do with it.

(Will I be shot for posting an MG link? )

https://www.mgclassics.org/single-post/2014/10/31/Vapor-Lock-The-Cause-Prevention-and-Cure

 

[KVH]

I'm thinking maybe you guys are absolutely right, after all. The "only" thing I did over the past year that might relate to this is that I replaced my fuel line to the carbs with a steel "brake" line made of black steel rather than the typical fuel line stock. That line is 1/4 inch, so I'll try replacing it. But, of course, I have another question. Do a dare replace that 1/4 line with a copper line? I ask because I have 10 feet of extra 1/4 copper line in my garage, and I'd "sort of" like to put it to use. My concern has always been that it's softer than steel and might wear through if it rubs on anything, like the water pump housing. What do you guys think?

 

[dklawson]

Use of copper for fuel line is a topic that periodically comes up and people take both sides without a lot of firm evidence to support one side or the other.

This is my personal opinion and is not based on much. Yes, the copper is soft but the main concern with it will be fatigue from vibration. If you make long runs of copper pipe, support it in P-clips along the way. Some will claim copper adversely reacts with fuel on a chemical level. I have not personally seen this or known anyone who has seen it first hand.

However, if this is a vapor lock problem the steel line is going to be "better" than copper. Copper is a much better conductor of both heat and electricity than steel. If you have engine heat causing vapor lock... the copper is going to transfer that heat into the fuel "better" and that is not a good thing.

 

[karls59tr]

I would install a Facet electric fuel pump with a see thru filter between the pump and tank and another filter with fine mesh between the pump and carbs. Are you running Stromberg carbs?

 

[PAUL161]

Hi guys, Jumped over here from the MG forum as all of our cars are related somehow and I enjoy reading about problems on other models and how they are solved. Question, Have you tried a tank of non ethanol fuel? Ethanol boils sooner than non ethanol and it sure sounds like vapor lock to me also. I have a 55 MGTF, know for high heat in the engine compartment and early in the game I put regular ethanol gas in it, on a hot day I ran into vapor lock problems, after switching to non eth, the problems went away and never came back. Just sayin. PJ

 

[KVH]

I'm back. I tried a new fuel line. No difference. After a good run, it doesn't want to start. Thirty minutes later it will start. I did notice this time that after turning the engine off the fuel is bubbling into the fuel filter. So, I guess the fuel is boiling. I'm using Quick Trip gasoline that says it "may" contain 10% ethanol. The weather has not been hot, and I've been driving at night. Do I try a new coil now? Do I buy gas elsewhere? Is the bubbling/boiling the clue to everything here?

 

[CJD]

The bubbling in the filter is a sign that the fuel is, indeed, boiling and causing vapor lock. If so, I put the problem on the gas rather than your car. I don't know about Arizona, but here in Texas the stations are only selling limited amounts of bottom grade gas following Hurricane Harvey. Following big storms that hit LA and TX, it is not uncommon to get tanks of bad, or very poor, gas. If you can burn off that tank completely, then refill with high grade from a large station, like Shell, Valero, or Exxon. These stations (should) get their gas straight from their company. 7-11 and other such stations get what they can get at discount from whatever supply they can find. With a fresh tank of good gas, I think 90% of your problem will be licked. Our TR design...with the carbs over the exhaust, very low fuel pressure, and a long run of line from the pump...is always going to be more prone to vapor locking.

Note: I used to put Texaco in with the "good" stations, but I've now had 2 incidents of bad gas from Texaco. I no longer trust them. The last incident was on my 2005 Jag, and cost me $1300 in parts before I figured out it was just a bad tank of gas!

 

[BillyB62]

I was experiencing similar symptoms but two weeks ago I swapped over from a copper line to steel and rerouted it away from the exhaust manifold. I do run a heat shield, but when I put the copper line in, I followed some of the pictures on the forum and it was routed within a few inches of the manifold. Working backwards from the carb, it now takes an immediate right turn from the float chamber and goes behind the under the radiator fill neck. I have had no issues restarting the car since.

Bill
TS63273L