Jump to content

Engine won’t start


Kevin.payne.15
 Share

Recommended Posts

I haven’t had a chance to start the engine for a couple of months and now won’t start at all.

I’ve checked to make sure the fuel pump is working by taking the fuel line off of the rear carb and petrol comes out - not fast but steady flow

ive put a strobe on the front spark plug line and turning the engine over, the strobe flashes so I think I’m getting a spark

ive taken a look at the carbs and the rear dash pot is very easy to lift where as the front one is very stiff.  I’ve investigated and taking the tops off, the rear dashpot was empty where as the front was full of oil. I don’t think this is the cause of not starting but it’s something else to fix 

ive lifted the dashpot when turning the engine over but haven’t seen petrol leaking out  - thought that I might have the fuel regulator too low(it’s set at 2 psi) but it’s always been the same 

so help please, what else should I check and also suggestions for the oil leak in the dashpot please

 

regards

kevin

Link to comment
Share on other sites

If your strombergs have cdse 150 with needle adjustment down the dash pot then there is an 0 ring under the needle adjuster that fails and lets the oil leak out,  the needle assy is held in place with a sprag star grippy washer pressed down the oil tube

Available as part of a repair kit for cdse carbs, 

Pete

Link to comment
Share on other sites

I would make sure the HT leads are labelled somehow, then take the cap and leads off and leave on a radiator in the house for a while to warm through. 

Not very technical, but it can help immensely, leads can get damp and affect the chances of starting. Likewise, take the plugs out and a quick clean up too. If really keen a blowlamp on each for a few seconds can pre-warm them a bit. Some plugs do not like getting wet with fuel, I think NGK are bad for that or were.

Recheck points are clean and correctly gapped, assuming points are fitted.

If still no joy, a small amount of petrol poured directly into the carb intakes....

 

Link to comment
Share on other sites

Ok thanks. Food for thought 

how does one get the needle out please  is it the screw on the side or the internal screw from the top  ? 

Also, whilst I know I have fuel getting to the carb, I was expecting when I lifted the dashpot to get some flooding of petrol ....but don’t  could that mean I’ve got the fuel pressure regulator set too low? It’s set on 2 which I think means 2 psi

 

kevin

 

 

Link to comment
Share on other sites

Kevin. fuel and air are sucked into the engine by the pistons  going down, fuel should not leak out the jet simply by lifting the piston. If there IS fuel leaking out the jets then the valves in the reservoirs aren't shutting the fuel off properly. Your problem could be also be these valves partially blocked and not letting enough fuel through. 

From what you say you appear to have top adjusting Strombergs? For a full description of them and how to service them look here under Carburettors part 1, 2 & 3. Theses are TR6 carbs and a bit bigger but essentially the same design as ours.  

http://buckeyetriumphs.org/technical/technical.htm

Doug

 

Link to comment
Share on other sites

Doug et al. Yes I have top adjusting ones. I’ve taken out the piston and removed the grub screw on the side. The needle is obviously lose but doesn’t want to drop out. It feels like it’s sprung loaded. I don’t want tug too much because I don’t know how it’s held in. I’ve read the Haynes Manuel for all the good that did. It just says remove the grub screw

Any clues as to how to remove please. If it comes out without twisting the internal adjuster will the needle go back in the same space ?

 

thnaks

 

kevin

Link to comment
Share on other sites

On 29/11/2017 at 10:43 PM, Pete Lewis said:

If your strombergs have cdse 150 with needle adjustment down the dash pot then there is an 0 ring under the needle adjuster that fails and lets the oil leak out,  the needle assy is held in place with a sprag star grippy washer pressed down the oil tube

Available as part of a repair kit for cdse carbs, 

Pete

Kevin,

Helpfully, the Haynes CD Owners Workshop Manual states that this screw is NOT removable; but it can be done.

You'll need to unscrew the top adjuster screw to release the needle - it's best to have the proper top adjusting tool for these carbs.

The screw can then be pressed or tapped back up the dash pot bore from the bottom - be careful the sprag washer will score the bore!!!

The adjusting screw is available from Burlen as part B20042 and comes with the o ring. The hex head in the screw is often badly deformed after years of twiddling. You may need a new sprag star washer too.

BUT... you started this thread because the car wouldn't start. Oil leaking past the seal will be quite slow and although annoying, just requires a more frequent top up - it shouldn't stop it starting.

David 

Link to comment
Share on other sites

Old fuel is often talked about but using the   cars less over winter has never stopped me starting anything over the past 20 years 

Cars left for many many months or years can can suffer from thick jellied fuel and blockages

Start with if the air piston is out can you see fuel a few mm below the jet   looking down its hole ?

If you bounce the car it should visually be seen  to  move  a little

If you crank do you get a spark from a HT lead held a few mm from the block ?

Slivers of fuel hose are particular pests which get stuck in the float needles and drop fuel evels

The buckeye site shows clearly how to repair these carbs but agree with David your barking up the wrong tree 

And after all the head probems you do have 0.010" tappet  gaps ?

Pete

 

 

Link to comment
Share on other sites

Kevin,

If you want to remove the needle you first need to put the needle retaining screw back into the side of the cylindrical air valve. As David says you can now unscrew the metering needle from the top using a 0.125 A/F Allen key (ideally use the special Stromberg tool) until the needle assembly emerges from the bottom of the valve. THEN you remove the needle retaining screw from the side and the metering needle should come out. 

I agree with David though. Replacing the metering needle O-ring is a "nice to do" to avoid having to routinely top up the dash-pots. It's unlikely to help with the starting problem though.  

Wayne

Link to comment
Share on other sites

Well that’s a worry then. Chapter 3 section 22 note 7 of the GT6 book says undo grub screw and even shows it in a picture. 

Im pretty miffed at Burlen because usually they give great advice but I spoke to them yesterday and they never mentioned anything other than an o ring at 53p each. So that’s all I’ve ordered. 

Yes agree that I started on not being able to start the car but with these things it starts somewhere but migrates to other issues as I put in my engine rebuild article last month

its the story of my car!

Link to comment
Share on other sites

Needle removal by grub screw applies to CD CDS   all fixed needle , bottom adjustable,   not CDSE  these have the top dashpot adjuster and sprung biased needles  unfortunatley held in with the adjusting nut and sprag washer , I would fit a new washer or flatten the removed or it will not grip on refitting.

Its cold , does the choke actually fully rotate the choke lever ?

Pete

Link to comment
Share on other sites

Kevin,

Like Pete I've never had a problem with fuel, but I always use the good stuff. Others who haven't used high octane tell me there can be a problem.

As already mentioned Buckeye Triumphs, carburettor overhaul, part 2 shows VERY clearly what's in the carb. Take a look. But I agree with the others the O ring ain't your problem. Did you try Easy Start?

http://buckeyetriumphs.org/technical/Carbs/CarbsII/CarbsII.htm

 

Doug

Link to comment
Share on other sites

1 hour ago, Kevin.payne.15 said:

Well that’s a worry then. Chapter 3 section 22 note 7 of the GT6 book says undo grub screw and even shows it in a picture. 

I've attached a picture of the arrangement in a CDSE carb (fixed jet, adjustable metering needle) which comes from the Haynes Stromberg carb manual. On the CDSE the grub screw doesn't actually retain the metering needle. It is there to maintain the orientation of the biased needle relative to the carb throat when the needle height is adjusted. If you take the grub screw out before turning the adjusting screw from the top the whole needle assembly will rotate and won't screw out. 

Wayne

 

 

IMG_1356.JPG

Link to comment
Share on other sites

Ok I’m stuck !  I’ve re inserted the grub screw in the side and can see that it’s engaging in the slot machined in the metering needle assembly.  If you “undo” from the top then the needle assembly moves out about 1 mm and the shoulder protrudes about 0.5 mm from the base of the dashpot.  And that’s about as far as it wants to go. 

Turning the needle adjusting screw is easy but then “jumps” as though it’s run out of threads and the “jump” is where it’s going over the first thread on the metering needle assembly

looking at the picture then the slot in the metering needle assembly has a fixed length and so unless the grub screw is removed then it won’t be allowed out - is this correct ? Should the needle be an easy remove or is it always very tight?  

I’ve tried screwing the adjusting screw in two threads and then pushing down (to try and encourage the needle out) but that didn’t do anything either 

so I’m stuck

help please ! Kevin

Link to comment
Share on other sites

Kevin,

Buckeye says

"To get at the O-ring, a steel rod is inserted in the bottom side of the air valve guide rod and gently tapped with a small hammer driving the adjusting screw and the retaining clip out the top of the air guide rod."

You will probably loose the retaining clip, which will ping out and disappear down the garage.!

Doug

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...