TR4 won't start - Heeeeelp

[i8pig]

Finished the engine rebuild ages ago and fired her up, no bother. Changed the throttle linkage, which needed the removal of the front carb, put everyyhing back together and ----- nothing!! Won't fire, never mind start.

I have checked the compression, 13 bar on all cylinders. I have reset the timing so often the plugs almost jump out on their own, I also know I have a spark because I have a set of those transparent plug cap type thingies that say so. I have twin weber 45s and a Facet red top pump and I have checked that fuel is being pumped to the carbs. I have a fuel regulator but not fitted it yet and I also have fuel in the tank. The pump seems to run for a long time, in fact it hasn't stopped yet but there is no sign of a leak anywhere. The plugs are not particularly wet and the valves operate correctly, there is no fuel coming out of the exhaust so I have no idea where the fuel that the pump continues to pump is going. Can anybody help?

Steve

[Guest ntc]

Finished the engine rebuild ages ago and fired her up, no bother. Changed the throttle linkage, which needed the removal of the front carb, put everyyhing back together and ----- nothing!! Won't fire, never mind start.

I have checked the compression, 13 bar on all cylinders. I have reset the timing so often the plugs almost jump out on their own, I also know I have a spark because I have a set of those transparent plug cap type thingies that say so. I have twin weber 45s and a Facet red top pump and I have checked that fuel is being pumped to the carbs. I have a fuel regulator but not fitted it yet and I also have fuel in the tank. The pump seems to run for a long time, in fact it hasn't stopped yet but there is no sign of a leak anywhere. The plugs are not particularly wet and the valves operate correctly, there is no fuel coming out of the exhaust so I have no idea where the fuel that the pump continues to pump is going. Can anybody help?

Steve

 

 

The pump will still run but should slow down when the float chambers are full,you need the regulator in place and set to 4/5

[TR 2100]

Finished the engine rebuild ages ago and fired her up, no bother. Changed the throttle linkage, which needed the removal of the front carb, put everyyhing back together and ----- nothing!! Won't fire, never mind start.

I have checked the compression, 13 bar on all cylinders. I have reset the timing so often the plugs almost jump out on their own, I also know I have a spark because I have a set of those transparent plug cap type thingies that say so. I have twin weber 45s and a Facet red top pump and I have checked that fuel is being pumped to the carbs. I have a fuel regulator but not fitted it yet and I also have fuel in the tank. The pump seems to run for a long time, in fact it hasn't stopped yet but there is no sign of a leak anywhere. The plugs are not particularly wet and the valves operate correctly, there is no fuel coming out of the exhaust so I have no idea where the fuel that the pump continues to pump is going. Can anybody help?

Steve

 

Since the engine started initially after rebuild, there can't be anything

fundamentally wrong with the setup, even though fine tuning will no doubt

be required.

 

I would tend to look at what you have played around with since initial running,

i.e. fuel supply but the fact that there is no sign of life tends to indicate

an electrical problem, even though you seem to have confirmation of a spark.

 

Thoughts -

 

Plugs "not too wet" - they don't need to be too wet, just a little wet,

that's enough to prevent an actual spark, even if the coil is doing it's job.

 

Coils can fail without warning. Mine failed completely after 3000 miles.

I had been out for a drive, just reversing into a parking space, stalled

and then - nothing. Maybe a weak spark that the plug caps indicate as a

spark even thougb it may be too weak to strat?

 

Fuel - air lock? Floats stuck? Squirt some fuel into the barrels and see

what happens.

 

Anything else you could have played around with while you were doing the

linkage?

 

No smell of fuel in the exhaust must be the main clue.

 

AlanR

[Guest ntc]

Since the engine started initially after rebuild, there can't be anything

fundamentally wrong with the setup, even though fine tuning will no doubt

be required.

 

I would tend to look at what you have played around with since initial running,

i.e. fuel supply but the fact that there is no sign of life tends to indicate

an electrical problem, even though you seem to have confirmation of a spark.

 

Thoughts -

 

Plugs "not too wet" - they don't need to be too wet, just a little wet,

that's enough to prevent an actual spark, even if the coil is doing it's job.

 

Coils can fail without warning. Mine failed completely after 3000 miles.

I had been out for a drive, just reversing into a parking space, stalled

and then - nothing. Maybe a weak spark that the plug caps indicate as a

spark even thougb it may be too weak to strat?

 

Fuel - air lock? Floats stuck? Squirt some fuel into the barrels and see

what happens.

 

Anything else you could have played around with while you were doing the

linkage?

 

No smell of fuel in the exhaust must be the main clue.

 

AlanR

 

 

The rotor arm?

[Icarus60]

Is there any chance that the carbs are now setup below the idle setting?

[brydon]

Hi

 

The rotor arm is a good shout, I'd also suggest you may have an air leak between the carb you removed and the manifold, you'd be suprised how common an air leak is.

 

I hope you find the culprit soon.

 

Kind regards

 

Andrew

[Badfrog]

Hi,

 

Sparks but no flood: I'd say the pump is running without effect (clogged, broken actuation or membrane....). Install another pump, set the pressure regulator at 3-4 psi at the carbs, air blow your jets and fire the beast.

 

Then remove the 45 DCOE and go for a sexy set of HS6 with TS needles and upgraded innards (radiused pistons, yellow springs, 8103 dampers). Rebore the manifold and engine side of the carb to 2".

Now you're set for some real speed.

 

Cheers,

 

Badfrog

[Ade-TR4]

I know it's obvious, but sometimes "obvious" is overlooked!

 

1 - Plug leads on in correct order?

2 - Plug leads/ cap/ rotor in good condition?

3 - Disconnect inlet pipe to carbs and see that the pump IS pumping.

4 - I had an interesting problem where the drive for the dizzy was 180-degrees out on the cam. Took some head scratching that one...

5 - Are Points & Plug gaps correct?

6 - Sacrifice a small chicken on the rocker cover and dedicate it to "Lucas - evil Prince of darkness"

 

Good luck!!

Adey

Edited October 19, 2010 by Ade-TR4

[adriantr4]

Hi Steve

 

After carb refurbishments my '4 ran progressively worse & worse - then other miscellanous things failed.

 

Heres what I did over a 12 month period

- "adjusted" the clamp on the distributor & accidently retarded the timing so far back it wouldnt start (oops)

- broken/ancient/intermittent LT lead within the distributor - replaced (Distributor Doctor)

- broken connector onto coil - resoldered

- new "red" rotor arm (Distributor Doctor)

- but the crucial and now-so-obvious items: new & decent HT leads & cap

 

It was the leads & cap that did the trick - the others were items that failed with age.

The old (very old) leads didnt make good contact onto the old cap either - but I did see a decent spark.

 

So: I wonder if you may see a spark - but it wont spark under compression? My guess is that the problem is electrical?

[Ade-TR4]

If you can't fix it with a hammer, you've got an electrical problem...

[i8pig]

Good afternoon all,

Thank you all for your suggestions, I had tried everything suggested with the exception of the chicken so I tried that, it didn't work but we did get quite a nice Sunday roast out of it so thank you Adey.

If any of you are interested, the problem turned out to be with the front carburettor. There are two bolts under the carb that are joined and locked by a tab washer arrangement, these lock the choke venturi in place and there is very little torque so the washer thingy has to lock. Mine didn't do its job too well and the bolt fell out, the venturi rotated and the fuel that entered the carb simply ran out of the hole that the bolt should have been in The funny thing is that both bolts are drilled for wire but Weber choose not to use this, much safer, method of locking.

I have removed both carbs, wired the bolts and refitted, the car has started.

Thank you Badfrog, I know I should have stuck with SUs but the noise is wonderful.

Steve

[PJM]

So it wasn't a non starter problem but a fuel leak. no wonder the chicken didn't work!