Dear forum-dwellers,

I took the series 3 out for a good old fashioned run the other day but only got half way home....
the story goes that i stupidly run one tank out of fuel as the gauge on that tank is dicky. i normally run it till it starves a bit then switch to the one with the good gauge so i know ive got fuel. after i did it this weekend it was starving and getting worse and worse. first i suspected ide filled the filter with crud but after stopping at lights and hearing the noises the pump was making it was evident it was on its way out. after a while it got to the stage where it was intermittently loosing all power then surging back to life, so i removed the pump and hit it against the curb. hey presto it came good. but not good enough to drive home up the freeway so for the first time ever i walked away from a car and towed it home.

it has also been hard to start when hot aswell lately so ide assume this is connected to the issue? it always starts strait away cold. im thinking its either the fuel pump or the fuel is vaporizing when it heatsokes as the fuel cooler dosnt work (ac needs charging).

any opinions or reassurance on the matter would be appreciated,
regards Jay.

 

First, correct me if I'm wrong but judging by the name and the location, I've seen your predicament before on V8Jagnut's Youtube channel?

Anyway, you're spot-on with the fuel pump. It's stuffed. Two things will happen when they go, you won't get enough fuel flow and when it gets hot that low flow will vaporize more easily. I had this issue with my Saab and just fixed it again on my S3. The S3 wasn't a bad pump again this time, it was just a pre-pump filter that looked like it had ingested a clay pot. Same symptoms, though. It would die out, start fine when cold but refuse to start when warm... the only difference was yours coming back to life when you knocked the pump on the ground.

 

Millster, you are indeed right if you are referring to my comments with Aussie50 on brads channel.

Im glad the hot starting problem can be attributed to this. my next issue is weather or not to risk it with a cheap pump like this Fuel Pump Jaguar Sovereign XJ XJ6 XJ6L XJ S XJS Coupe Convertible 1979 1993 | eBay

I would prefer a oem bosch pump but considering they are worth upwards of $150 im thinking i might just buy two of these cheapies and keep a spare in the car so if it craps out on a long trip i can swap them. the reason im going for this pump is becuase its only 20 minutes from my house. they say this pump is only up to 82, with my car being an 82. what was the difference?

What filter do you use pre the pump? ide like to install a filter before the pump but ide imagine it needs to be a rather large one with half inch lines. if i could get one of the reusable ones with the ceramic type filter in them that screws appart it would be perfect as they fill up rather quick. if i do this i suppose there wouldnt be a need for the after filter pump, and if anything i could put a small one in the engine bay

thanks,
jay

 

Mate, I've got exactly the same symptoms as you:
- Starts easily when cold, idles well
- Hard to start when warm
- Sometimes I even have a backfire in the intake when starting (fuel-starvation right?)

My first fuel pump was the original Lucas. It was leaking out one end where the plastic joins the metal. Replaced with generic pump. Car worked fine, when I stupidly decided to use the left tank. The new pump began making a noise, when I removed it a bunch of rust came out the pump and the pipe. Needless to say, had to replace again.

I've now bought a new pump and installed a small inline filter BEFORE the pump. The car still exhibits the symptoms above, but especially when the tank is low on fuel. I'm now wondering if the inline filter is inhibiting the flow of fuel on the suction side?

I'm so bloody tired of this problem and buying pumps! I'm going to try run without the in-line filter (risking my new pump) to see if this problem goes away.

 

the issue with fuel filters, ide imagine, is that its easy to push 60psi of fuel through small holes but when it comes to sucking a large volume of fuel through a filter when the fuel is basically graverty fed its very restrictive.

one solution may be using a t piece and two of the large oem filters or one of the clear ones with just the stainless screen in it. ide imagine a paper element would clog too quickly?

the best thing would probably be a glass sediment bowl like on old cars. or maybe modifying the in tank filters to accept the material screen type filters on modern systems.
this weekend ill drain the tanks again and flush them out and see what can be done woth the filters as im sure if i put a filter in front of the pump it will block strait away and starve the pump.

ide be interested to what anyone else has done to get around it

regards jay

 

Those would be the comments I was referring to. It's a small Internet, indeed!

Anyhow, I wouldn't shy away from the cheap pump for now until you know if there's an underlying issue that caused the previous one to pack up. With as easy as it is to change them on the Jags and as inexpensive as that pump is, it'll at least get you back on the road and once you are comfortable with the fix you could get a better quality pump. Near as I'm aware, there's no difference in the pump beyond '82 other than maybe fittings? I'm at a bit of a disadvantage there what with not having an entirely stock fuel system.

As for what I use as a pre-filter, I have a large OEM style connected to the tank feeds. This allows plenty of fuel to stay in the filter and staves off starvation from the pump pulling all of the fuel out of the filter and having to let it refill. I borrowed the idea from my old Ford Ranger that had a similar arrangement from the factory. It obviously requires frequent checking, but I've been getting about a year out of a filter before it starts to develop a terminal blockage. I also do continue to run the factory after-pump filter just for extra insurance. If the element in the pre-filter collapses and the pump puts a blast of garbage up, at least my injectors are safe. With the way my system is plumbed, I have proper fuel pressure at my injection system and vigorous return flow so I have no reason to believe there is much impedance from the double filtration.

The big thing to make sure you do is let a little fuel flow via gravity after you've pulled the filter to flush any rust or sediment that may still be in the lines. That way you don't immediately block the new filter.

Without pulling the tanks and lining them proper, it's a bodge job to be sure. I'm getting around to that point myself once time allows but even then I'll probably run the dual filters just because it doesn't cause a problem and it's a little extra insurance for my expensive pump.

 

My problem is definitely far, far worse when the tank is low on fuel. As soon as I fuel up, runs better.

I'm now convinced that either my pump isn't powerful enough (do these pumps suck on the suction side or just pump?) or the pre-pump in-line filter I've added is causing a shortage of fuel.

 

Wix 33299 (Napa 3299) works well as a pre-pump filter.

The pre-pump filter idea generally works well and is recommended. Of course, if the fuel is very dirty the filters clog quickly...which is exactly what they're supposed to do.

A pal of mine had rusty tanks. He didn't want to remove them...big job....so he flushed them out best as possible in-situ and then bought a slew of the 33299 filters.

The first pair clogged in a 3-4 days. The second pair took 7-8 days to clog. Then 30 days. Then 90 days. Eventually all the loose rust and gunk was captured by the filters. I think he went thru about 10 filters in 6 months

Now he just removes the filters once a year and blows thru them to check if they're clogged. They been clear for several years

Cheers
DD

 

I would add that the tanks be drained and the sock filter on the pickup be removed and replaced. But, if pre-pump filters are installed, I see no problem with omitting the sock filters. There are two fittings behind the valence. Remove the large one for access to the sock. Be prepared with a big catch pan. As little fuel in the tank as possible is advisable.

As fart as I can tell the tank to pump feed is gravity and really does not rely on the poor sucking ability of most if not all electric pumps.

Carl

 

Doug, I've installed something similar to the Wix 33299 (the ones I used were fram and see through). However, I only put one and I put it just before the pump AFTER the change over valve. Is it generally recommended to put two before the changeover valve?

 

The advantage of two filters....one between each tank and the changeover valve....is that the changeover valve is protected from muck and rust.

A bonus is that if only one of the two filters clogs you'll know which tank is still mucked up

Cheers
DD

 

Another good trouble shooting idea when you have fuel starvation and hard starts only when hot is to check the fuel pressure regulator, as it can cause the very same symptoms.

 

Thanks guys. Stellar, which is the fuel pressure regulator?

Doug, I'm scared of my left tank, it's already chewed through one fuel pump!

 

Her is a Pictures of the fuel pressure regulator.

 

Well it seems I have found my problem... All this time I was checking the pre-pump filter while fitted and I couldn't see any dirt. However, when I removed it.. Look below (that's after blowing a lot of crap out - it was difficult to blow through it). New filter in... Bloody *******.