Poor running - Fuel Tank Replcements

[hoops]

I have posted a couple of times on the Facebook group but thought I would post here to keep track a bit easier.

I bought my Dolomite 1850HL back in August, and ended up bringing it home on the back of a recovery truck as it started spluttering and cutting out not long after I filled up with fuel. Long story short I think when I brimmed the tank, it bought up a whole load of crud from the bottom of the tank.

Since then, I've had some electrical issues and it seemed to be running fine'ish other than not revving over 3,500rpm. Since then I have now replaced the following:

New Coil & Electronic Ignition via the SimonBBC kit
New Magencor HT Leads via the Club
New Distributor Cap (Rotor looks fine and is nice and clean)
New Spark Plugs
New Fuse Box
New Hazard & Indicator relays (not ignition related but now all working)
Checked wiring on the ignition switch and all seems fine, sprayed with contact cleaner and driven while wiggling the cables and no cutting out.

Broken earth cables on the back of the Tachometer and in the distributror (from vacuum advance to mounting plate) have been repaired.

Since then, the car now revs fine both under idle and under load past 3,500rpm, and will happily sit on the drive for 10-min. Take it out for a drive and a few minutes down the road it starts to splutter, not rev and then cut out. I can usually manage to get it going after trying for 20-30 seconds and pulling the choke cable out a few times, pumping the accelerator etc.

I have cleared out the carb float chambers a couple of times now, there was a fair few small bits of stuff in them both times, as well as replacing the fuel filter twice.

I can only think that the continued issue is the fuel supply and that a replacement tank might be the only option?

Are there any other solutions other than a new one via ChrisWhittor?
https://www.chriswitor.com/proddetail.php?prod=312385A

Unless there is anyone in the Oxfordshire/Swindon area who could double check I've not missed anything?

[Carledo]

I agree your problem is most likely related to fuel flow, I seem to recall this car was stood for some time before your purchase.

That being the case, I would carefully check all the solid fuel pipes for blockage/restriction, the bit that goes up over the axle is particularly prone to blockage with calcified crud when left standing. One I have here that looks perfect and I use for a pattern to make new ones, is so thoroughly blocked that 100psi of air pressure won't clear it and nothing is rigid enough to clear the blockage (which is, of course , right in the middle!) but flexible enough to go round the tight corners! Also, replace all the rubber fuel hoses (most emphatically including the 3 under the car) with new ethanol compatible R9 hose and take care to get a good known make like Gates Barricade, there are a lot of fakes out there!

Pay especial attention to the pipe in the bottom of the tank as i've seen these blocked solid with crud or only letting a trickle of fuel through, enough for idling, but not for sustained running at higher revs. I like to rod this out with an opened up wire coat hanger - assuming you can find one these days!

Take the tank sender out and examine the bottom of the tank for crud and corrosion, if it's too bad, then a replacement tank is the best option. If it looks clean and silver around the end of the pickup tube then the tank is probably OK and the pipes just need a clear out.

One more thing, check carefully that the fuel filler cap is of the vented design, a non vented cap will create a vacuum in the tank that stops the pump from pumping in quite short order! Some Triumph caps are made with the 3 prong fitting , but without vents as their tanks are separately vented.

I have the facilities here to bend up new copper fuel pipes if you need some, but, once made, they'd be impossible to post, you'd have to collect from South Shropshire WV16!

There really aren't any NEW tanks available except Chris Witor's Alloy offering, it's a lovely thing but i'd regard it as a last resort, purely on cost grounds! However the news is not all bad, there are still a few good used tanks in the world, I have a couple myself. I'm sure someone will part with one for a more sensible price. But check it out thoroughly first before changing the tank.

Steve

[hoops]

Thanks for the detailed reply, I have today cleaned out all the lines and carbs forward of the fuel filter and will give it another go tomorrow.

I managed to grab a quick video of the spluttering, it runs fine and then this kicks in.

https://www.youtube.com/watch?v=Hv6-2tuX4oE

[hoops]

Just to update, after the cleaning out in the previous post, the car has now been running faultlessly in terms of any spluttering on two seperate ~30min drives out

[Matt Cotton]

Great result Rob!

We will have to meet up for a drive out somewhere when the weather warms up and the salt is off the roads!

HNY!

MC

[hoops]

Great result Rob!

We will have to meet up for a drive out somewhere when the weather warms up and the salt is off the roads!

HNY!

MC

Certainly, now I can (touch wood) trust it to be more than 5-miles away from home! Just bought an Accuspark Strobe so I can correctly set the advance as when I refitted the distributor it was just eyeballed. Now that it seems to be OK, I'm putting off the replacement fuel tank, for now unless it becomes problematic.

Completed jobs since it arrived in August
-Installed new rear seatbelts
-New Drum Pads & Handbrake Cables
-New Revolution 13x5.5 4-spoke alloys and Continental EcoContact 175/70/R13 tyres
-New Accuspark Coil and SimonBBC Ignition with Magencor Leads, Cap & and Plugs
-New engine breather hoses
-Renewed various earths to get Tacho and Indicators working again (with new relay) and new 4-way fuse box

I plan to do some more planned servicing with this list of jobs this winter in prep for an MOT in the Spring.

-Refit fuel tank breather hose, new one installed but can't for the life of me get the hose onto the fuel cap assembly!
-Fit new window rain seals, already have these along with clips
-Tune Carbs
-Fix speedo, have a new cable just need to fit
-Engine oil flush and refresh (purchased Miller 20W50 and oil filter)
-Coolant flush and refresh, fit new thermostat and seal (current seal is weeping)
- - - Also looking to 'update' the coolant system with the Volvo Header tank mod and possibly a new rad/electric fan with silicone hoses but TBC.
-Fit some underlay/sound dampening
-Fit a new Headunit and speakers (Alpine CDA-117RI & 90s KEF KAR speakers plus small sub/TBC)

Enough to keep me going! I did take it out earlier this week and did a quick video, still needs some tuning on the timing and carbs but getting there!

https://www.youtube.com/watch?v=Cf1CO3XE7kQ

[Carledo]

On fitting the tank breather hose, it's much simpler to remove the metal upper pipe which is only secured by the 2 hose clips at the bottom. Take out the millboard panel (if still fitted), slacken the 2 hose clips on the filler pipe and remove the fuel cap. The upper pipe can then be twisted free of the tank at the bottom and withdrawn from the seal in the 1/4 panel and pulled out complete with the breather hose. Change the hose at the fill end and replace in reverse order.

HTH, Steve

[hoops]

On fitting the tank breather hose, it's much simpler to remove the metal upper pipe which is only secured by the 2 hose clips at the bottom. Take out the millboard panel (if still fitted), slacken the 2 hose clips on the filler pipe and remove the fuel cap. The upper pipe can then be twisted free of the tank at the bottom and withdrawn from the seal in the 1/4 panel and pulled out complete with the breather hose. Change the hose at the fill end and replace in reverse order.

HTH, Steve

Excellent, it's one of those you can see the pipe, and reach in with the hose to the right place but not get any real purchase to push it on with the various contortions to get into position!
I shall give that a go!

[B8WLY]

Have you got an in line fuel filter currently fitted ??

I have one in my Sprint which when I changed it last year had done a brilliant job. The amount of debris it picked up was astonishing.

I also have a filter king fitted which again ensures a better delivery of fuel to the carbs.

Just a thought if you want to go a bit further.

Richard.

[hoops]

Have you got an in line fuel filter currently fitted ??

I have one in my Sprint which when I changed it last year had done a brilliant job. The amount of debris it picked up was astonishing.

I also have a filter king fitted which again ensures a better delivery of fuel to the carbs.

Just a thought if you want to go a bit further.

Richard.

Yes, the old one (and spare) that came with the car were both pretty rubbish, they did both have dark bits in them that they were 'catching' but both had visable damage in the filter after a while so I guess it was getting through. I have since fitted a febi bilstein one and has been fine since. I have stocked up with some new ones from Robsport for future.

Do you use the filter king with an electric fuel pump? My car did come with an aftermarket electric fuel pump installed but disconnected (no explanation from the previous owner), it does 'work' when hooked up to the 12v battery but unsure if it would make a difference.

[xvivalve]

Probably disconnected as without a pressure regulator it is likely to overfuel SU carbs which only require minimal fuel pressure.

[B8WLY]

Have you got an in line fuel filter currently fitted ??

I have one in my Sprint which when I changed it last year had done a brilliant job. The amount of debris it picked up was astonishing.

I also have a filter king fitted which again ensures a better delivery of fuel to the carbs.

Just a thought if you want to go a bit further.

Richard.

Yes, the old one (and spare) that came with the car were both pretty rubbish, they did both have dark bits in them that they were 'catching' but both had visable damage in the filter after a while so I guess it was getting through. I have since fitted a febi bilstein one and has been fine since. I have stocked up with some new ones from Robsport for future.

Do you use the filter king with an electric fuel pump? My car did come with an aftermarket electric fuel pump installed but disconnected (no explanation from the previous owner), it does 'work' when hooked up to the 12v battery but unsure if it would make a difference.

My car does not have an electric fuel pump. Standard Sprint fuel pump. As Alun stated the Filter King just adds another process where you have a better understanding of the pressure fuel reaching the carbs. If you are getting good fuel supply at recommended pressure levels it just gives more confidence you don’t have an issue between the tank and carbs. Some may say this is over kill !!

[Carledo]

Have you got an in line fuel filter currently fitted ??

I have one in my Sprint which when I changed it last year had done a brilliant job. The amount of debris it picked up was astonishing.

I also have a filter king fitted which again ensures a better delivery of fuel to the carbs.

Just a thought if you want to go a bit further.

Richard.

Yes, the old one (and spare) that came with the car were both pretty rubbish, they did both have dark bits in them that they were 'catching' but both had visable damage in the filter after a while so I guess it was getting through. I have since fitted a febi bilstein one and has been fine since. I have stocked up with some new ones from Robsport for future.

Do you use the filter king with an electric fuel pump? My car did come with an aftermarket electric fuel pump installed but disconnected (no explanation from the previous owner), it does 'work' when hooked up to the 12v battery but unsure if it would make a difference.

If you have both a mechanical pump (working) and an electric pump (inline but not powered) then I think your low fuel flow problem predates your ownership! Someone has fitted the electric pump in a (fruitless) attempt to boost the pressure at higher revs. When the REAL problem was probably mostly blocked pipes. I see this ALL the time on cars that are recently recomissioned or in for recomissioning. It's got even worse since ethanol fuel became a thing, which has added gummy mess and rust to calcified crud!

Personally, I wouldn't bother with a pressure regulator unless you are having flooding problems. Most of your problems are at the other end of the scale!

Steve