HI all,
So I've driven a mile before breaking down since acquiring my 1985 4.2 nearly 3 months ago now!
Got to the local tyre shop, it spluttered and conked out and wouldn't restart.
Got it home and put a new fuel pump and filter in and all good.
That was about a month ago now, and since then have only manouvered her in and out of the garage to do bits and pieces... trim etc and new lights etc getting ready for an MOT attempt.

Then today, took her out the garage, let her run for 10 mins and warm up nicely, no problem as has been the norm for a month.

Then just about to run up the road and back before putting her away and suddenly... starts, runs really rough, hesitating about to stall, then conks out. Won't restart. Turns over, almost catches, maybe even runs a couple of seconds really rough and cuts out again,

Any ideas of where to go next?

The background of the car is only 85k, elderly previous owner, it sat around a long time I think, but not sure how long... is it possible old fuel could be causing it? I did put a gallon of new fuel in the nearly empty tank but made no difference.

Thanks a lot for your help.

Alasdair.

 

PS tanks switch over no problem! One is half full one was low but I added a fresh gallon.

 

Alasdair, the gas tanks are famous/infamous for rusting inside. If they even hear rain on the roof of the shop, they will start to rust. If you got a mile out of your first startup, replaced the pump and filter and got another half hour of run-time before same problem, I think rust in the tank(s) and clogging the filter is the culprit. Classic symptom of fuel starvation is loss of power, sputtering, rough running and then quits. Adding simple in-line fuel filter(s) before the pump, inside the boot, will allow you to change them when they clog and probably be cheaper than replacing the main filter all the time. Much nicer on the pump too.

The lower section of the rear wing (fender) has a hard rubber/plastic plug that covers the drain plugs for the tanks. Small plug is best used to drain the tank, big plug removed to access tank filter on the end of fuel line and see how much rust chips and crud comes out. Piece of heavy wire bent 90* and use it to "sweep" inside the bottom of the tank. Others will chime in on ways to rehabilitate the tanks. If there is a lot of debris inside, I always vote to replace the tank.

Dave

 

Have you drained the fuel out and checked the gauze filters at the drains ? It does sound as if the pump can't draw any fuel from the tanks. A tank flush would probably cure the problem..

 

I have in the past removed the drain and.the mesh filters at the bottom of the tanks, then removed the senders at the rear of the tanks,
then put a garden hose through the fuel sender hole and cleaned the inside of the tanks with water prssure, let them dry overnight and reassemble next day.

 

Thanks for your help, seems like I have a fair bit of work to do... I suppose it would be good if it is just the tanks, though new ones are 250 a side so hoping not to need that,

so one question is the fuel pump makers say debris causes most failures, but some people say the pumps are robust, and in theory it could be the post pump filter blocking up, but I guess it’s too hard to tell.

sounds like I should do the pre filter mod, hard to get reasonable cost ones here in the uk like the wix one recommended in other posts they’re £25 a piece here

I do have some boot floor small rust holes to attend to so maybe have to bite the bullet and try and take this all apart and drop the tanks

hopefully doable in a single garage as that’s where she’s stuck!

I guess I should get new drain plugs and gauze filters ordered too

would be nice to actually drive her one day!!!

 

the mesh filters are brass and they rarely need replacing. All you need are new rubber seals for the bottom of tanks. About $ .50 cents each.

on reassembly, use HYLOMAR sealant applied lightly to both sides of new rubber seals.

replace fuel filter again.

 

Imagine your lawn mower blade spinning around inside the close fitting housing at 3000rpm. Now imagine running over a loose pile of very small stones (pea gravel) and listening to the mayhem taking place. That's what is happening inside your fuel pump as bits of decayed steel are sucked through it. The "robust" goes away pretty quickly.

The pre-filter I mentioned is a simple inline filter that install by simply cutting the fuel line ahead of the pump and inserting the nipples in each end of the filter back into each end of the cut line. Should be a staple in any auto parts store or recreation vehicle shop.

As Jose said, just inspect and clean the mesh filter and get a new seal for the big drain plug, you don't need to replace the metal plugs.

Factor in all of your estimated expenses over the life of your ownership due to living with rusted tanks. You may find that 250 quid is not such a bad deal.

Dave

 

I installed two k &n glass filters, so I can see if they are blocking/blocked. They come apart and can be cleaned and reused. 6 bucks a piece on Amazon will look for the link

 

Cant make the link work from phone, but here’s a screenshot.

 

This is what in-line filter looks like.

 

hi there, quick update, still not starting and maybe need a plan B!

not touched the car for a couple of weeks, and from cold it started and runs for a second or 2 at the most then cuts out. Then it just cranks over and won’t restart.

my assumption is still fuel supply being the starting issue

so I changed the fuel filter again but no difference, and the already new one I’d put in a few weeks ago did not seem blocked. I’ll test the fuel pump next again as replacing that solved it before albeit very briefly, but don’t want to be buying fuel pumps all the time!!!

So my plan A was to drain the fuel tanks and fit new tank filters and then prefilters but all the damn screws on the valances are rusted and just stripping the heads when I try to budge them so I can’t move the valance and get the bung off the drain plugs....

Any tips on getting these tank drain cover things off?!?

My car is pretty much original and think these are the original rusty screws!

So I either need another plan A to get the tanks drained and flushed...

or go down a plan B route of just prefilters but I’d need some transparent ones I think ? to then work out if I need to go back to plan A and flushing rust out of the tanks.

does anyone think these look ok for the prefilter job?

https://www.advancedfluidsolutions.c...ils-6034-p.asp

i know Wix 33299 is recommended elsewhere but not stocked anywhere here. There is an online specialist doing a Baldwin equivalent but still £10 a go plus shipping so I’d be looking at £25 every time a filter needed replacing which could be frequent if I can’t get these tanks flushed! Plus I’d rather something transparent to see if it gets blocked.

Thanks in advance for any thoughts and tips! And any recommendations for prefilters, I gather they have to fit 1/2 inch ID.

thanks, Al.

 

I drained my tanks. A bit over whelming. but, a lesson learned. I forgot that I had tanked up before the engine failure !!! the car did not run for about 5 years. I did not want old gas in my LT1!!!

No need to remove the valance. Each has a large rubberoid plug/ I removed mine by force and ruined them/

should have opened the small plug first to drain. No, the large one came out!!!

Little dettius in my tanks. I got lucky and reused the old gasket. No leaks.

Others ahve methods to replace the valance plugs. I merely omitted them

Old theory on water. Keep it out and provide a drain. A collection point for mud a rust, Removed...

Knock on wood 15 years later, all good..

Carl

 

So have finally drained my tanks...!
yes quite a job... getting rid of a few gallons of rusty old fuel carefully!

flushed some fresh stuff through the tanks,

a quick hoover with a small flexible hose extension for any loose rust once it dried
new tank sump filters and gaskets in...

prefilters installed too with some new hose! Pic below!

20 litres of fresh fuel in spread between the two tanks...

petrol stations are really underrated you realise when trying to get a decent amount of fuel in by yourself!

and she finally splutters into life, struggles a bit on the right tank still though.

and now a leak coming from the switchover valve...

just one thing after another with this fuel system, but getting there thanks to the forum expertise!

oh and my new fuel pump is now noisy... I hope it’s just air in the system,but for 40 quid I think I’m probable best to get another one in

...hopefully one day soon she’ll make it to the garage under her own steam for an mot test.

 

Very good, though you may have to keep at it. I flushed my tanks (with water) twice, and it still took five pre-filter changes on my '86 before the gas tanks were clean enough for everything to just work reliably. Don't get discouraged, you are going to love that drive when it happens.