504 Ti won't start

Could be seized pistons in the hydraulic head. Easy to get at but you will need the gasket unless you're lucky.

Crack the lines at the injectors and see if it's getting fuel. If not, it's the above....in all likelihood.
 
1915 type 153 said:
Or it might be as simple as a blocked filter at the bulkhead. Check you have fuel getting to the injector pump before you pull anything to bits
Click to expand...
I pulled the filter out this afternoon. The element wasn't blocked but the petrol in the bowl was quite dark. It might be as simple as very stale fuel in the system and not enough pumping time to flush it back through the return line.
I'll get a new element and run the fuel pump with the line off at the injection pump to make sure I've got fresh juice all the way through, and try again.

I'm still annoyed with myself for not continuing to run it periodically after bringing it home. I was even surprised when I worked out how long ago it was that Graham serviced it for Dad.
 
My Ti sits in the garage with a trickle charger on it. I might start it 2 - 3 times a year. Starts first crank every time!
 
That's what this one used to do ... until I neglected it. Kept the battery charged, but there was so much stuff stacked in and around the poor old thing that it was just too hard to get to. Now I'm paying the price.
 
Of course but you own it and they're not thick on the ground. You're a lucky man.
 
Dad gave it to my son, Peter. I'm just the storer and fixer upperer.
 
Time for an update. I hope Type 153 in NZ is having more luck than me.

I now consider myself lucky that the car wouldn't start. When I got under the rear to replace the filter, I discovered that the fuel pump's 3 rubber mounts had torn free and the pump was hanging from its hoses and behind the diff, and the short piece of hose between the tank and the pump was hard and cracked.

I managed to get some similar, if slightly longer, rubber mounts from the local car parts shop. What a nightmare it is removing the old ones. Terrible access for a spanner. Nuts hidden from view. And 43 years of corrosion on the exposed threads of the tiny studs makes the final few turns of the nuts very difficult, when the only thing to grip on the visible side is a small lump of very flexible rubber.

Anyway, I managed to remove them, along with a goodly amount of knuckle skin. Fitting the new mounts was fairly easy and despite their extra length, there was still plenty of clearance between the reinstalled pump and the spare wheel cradle. I replaced line filter and decided to test the pump using a jerry can. The car is up on jack-stands so I've got a reasonable amount of space underneath. I put a full 10L plastic container of petrol under the car and put a long piece of hose on both the filter and the fuel return line. I stuck both of these into the fuel container, and switched on the ignition. The pump ran properly and drew petrol from the container, and I could hear the return line dribbling petrol back into the container. Looking good so far. I switch off the ignition again. Then I noticed petrol on the side of the engine block. Turned on the ignition again to see where it was dripping from and found it spraying from a split in the side of the hose that runs into the injector pump.

Next I decided to refit the hoses to the tank as I now knew that everything was fine through as far as the sediment/filter bowl on the bulkhead. Crawled under the rear again and realized that I'd forgotten which tank connection was which. I remember thinking when I removed them weeks ago that it was obvious and I didn't need to mark them. However, one stub comes straight out of the tank, horizontally, while the other comes out at an angle, with an upward inclination. That tends to suggest the inclined one is from the pick-up while the one going in horizontally is the return line. But that means when connected the rubber hoses will cross and it doesn't look right. So now I'm not sure. I connected a length of tube and blew into one of them. I thought I might be able to detect the slight resistance of the strainer on the pick-up line. But I got complete resistance. I tried the other with the same result. Both lines completely blocked! So this is why the car wouldn't start.

But how can this be? I can see how the strainer can become blocked, but what could happen in the tank that would block the return line?

So I poked a length of thin welding wire down each tube and pushed very hard. Nothing happened on the first. A complete blockage. But when I tried the other, it broke through. It now seems like the tank is going to have to come out and be thoroughly cleaned out.
It appears to be held by only 3 bolts. One at the front and one at each corner at the rear. The Haynes manual doesn't mention removing it. This is where I've left it for today.

How do I remove the tank?
Is there access to the bolt heads through the boot floor? (The boot is full of Dad's spares, so I haven't looked yet).

Which of the two tank connections is the pick-up?
The one closest to the front of the car, or the other one?

Any helpful suggestions gratefully received.
 
I'm a bit rusty on this but 504 fuel tanks are held up by brackets underneath. If you check around underneath you should be able to unbolt the brackets and the tank, with possibly a bit of encouragement, should drop down. Don't forget to disconnect all pipes and the wire for the fuel sender first.
 
Thanks Peter,

I'm a bit rusty too. I haven't crawled around under a 504 since I sold my 1970 1800cc model 25 years ago. I can't remember what its tank was like, but this one has a wide flange running around it where the upper and lower halves are welded together. It appears to simply hang from 3 bolts through this flange. There are no brackets under it. One of the bolts is very long, and extends well past the nut. Much longer than necessary. That leads me to believe that it isn't an original bolt, and that they are bolts and not captive studs; therefore the heads must be accessible to a spanner. I guess I'll have to unload the boot before I'll know. I need to get access to the wires to the sender anyway, as you pointed out.
 
Unless my memory is dodgier than I thought, all 504 fuel tanks have that flange and, in fact, are almost identical except for the extra pipe which was included for Tis as well as being introduced for venting of petrol vapour from the engine with the change in pollution control in the mid '70s. I think the attachment method is the same for all.

After just now checking a tank-less 504, there are two studs securing the tank at the back via two flat plates - brackets. At the front there is a flat hook shaped bracket about 70mm across that the front tank flange hooks into thus holding the front end in place. Don't know where your long bolt is but if it's at the front then maybe they lost that bracket.
 
Thanks Peter. Probably my misunderstanding of what you meant by bracket. I thought you meant some sort of bracket or steel 'strap' that passed beneath the tank to hold it up, like on many plastic tanks.

I've had a look underneath again, and the very long thread is the one near the rear LH corner of the tank. It's next to the ends of the two rubber breather pipes just behind the lower edge of the rear 1/4 panel.

Something else that I just noticed too. When I drained the tank a couple of weeks ago, as the last of the petrol dribbled out (took ages), some of it spread across the bottom of the tank, around the drain hole, wetting it for maybe 150mm to 200mm radius. That area is sticky to touch. Not oily; sticky. Are there any rubber components inside the tank, other than the filler hose which should not be permanently submerged, even when the tank is full - which it wasn't.
I can't think of what the sticky residue could be. This must be what is clogging the outlet and return tubes.
 
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Hmm, no long bolt or any bolt down that end near the pipes and that's on a 1977 (1978?). I doubt that there are rubber components inside the tank except for the plastic float etc on the level sensor. The filler hose isn't submerged either, it fits around a collar that projects above the tank.
 
Thanks Peter. I'll try unscrewing it and see what happens. If it turns, it's a bolt and I'll need access to its head from inside the boot.

I've edited my previous post. I left the all important n't off the end of the word should when referring to the submersion of the filler pipe.

When I drained the tank, it was into a plastic oil change pan. Rather than being clear, it was inky in appearance. Even when only a few centimetres deep, I couldn't see the bottom of the pan. The petrol was black. I assumed that it was suspended sediment or rust particles, etc. I transferred it to a jerry can for disposal. I've just checked it again. It's still inky. It hasn't settled and there's no sediment. Something has dissolved in it! What on earth is going on!

Much more investigation is needed. It's a very good thing that the car didn't start with this stuff ending up in the injection pump and injectors.

Surely it isn't just gum and varnish from oxidized old petrol. It's been sitting for 3 years in a shed with all the seasonal temperature changes, so some will have evaporated. I have no recollection of how much was in the tank when it was garaged. Even back then, the petrol in the tank wouldn't have been fresh.
 
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So which of the two tank connections is the one for the fuel pump?
The one closest to the front of the car, or the one closest to the rear?
 
UPDATE

Success! Well, sort of.
The electric pump is now refitted on new rubber mounts. The rear filter and its tired rubber hoses replaced. I decided to test the pump by extending its suction line and the fuel return line into a 10L jerry can of petrol under the back of the car. (It's up on jack stands)
I turned on the ignition and the pump ran normally and soon returning fuel could be heard trickling back into the jerry can. So I had new clean fuel flushing through to the engine and back. Then I discovered a spray of petrol from a longitudinal split in the hose leading to the injection pump. Another thing that could have been disastrous had the engine started first time and I'd taken it for a drive.

After replacing that and trying again, with a goodly dose of Aerostart and connecting 2 batteries, she fired and struggled into life, albeit very roughly. It felt like it was running on 3 cylinders. More things to worry about. Clogged injector pump or blocked injector? Could be expensive. Then I checked the ignition and discovered I'd transposed No.1 and No.3 plug leads!! Doh! Fixed that and she ran beautifully. Ran it for 15 mins and gave it a good warm-up to get everything hot and circulating. Ran about 1L of new petrol through it from the jerry can, so now the only problem is the clogged tank connections and the gunk inside it.

I set about removing the tank next. Not so easy. The two rear bolts are captive, so you only need a socket to remove the nuts. The bolt on the front mounting 'hook' has a captive nut, so again only a socket is needed to remove it. All nice and easy. To disengage from the front 'hook', the tank has to be slid rearwards about 2cm. The rear bolt holes are slots to allow this. BUT, there is less than 1cm clearance between the flange at the rear of the tank and the rear of the body. The car has never been in a collision, so I've no idea why there is insufficient clearance. I can see no way of removing the tank without bending (significantly) the 'hook', or cutting it off.

If I half fill the tank with petrol or say acetone or paint thinners, and let it soak for several weeks, is it likely to dissolve the muck and allow it to drain out? Does anyone have any experience doing something like this?

And which of the 2 tank connections is the one for the fuel pump?
 
After removing the two nuts at the back and removing the filler pipe and fuel pipes at the front the tank should hinge down at the back which will allow you to slide it back and out from the hook. This whole process is normally fairly easy.
 
Thanks Peter,

That's strange. The tank doesn't want to drop at the rear at all, and since the slots are quite long and the tank is as far forward as it will go on the slots, I assumed that they were there to enable it to be moved backwards to come off the hook and be lowered at the front edge first, in order to clear the inward curve of the rear valance panel.

All hoses are disconnected. The only thing I haven't removed are the sender wires. The black plastic cap in the floor of the boot is stuck tight and looks brittle when I tried to prise it out with a screwdriver. So I left it and assumed that I could probably get access to the sender wires when the tank was lowered a bit.
 
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