WIP: Diagnostic Mode - Updated, Clarified and Simplified

[SD1too]

Originally Posted by T-Cut

10 Country Code
This is just a list. There may be a code displayed for each, which I don't have. I haven't physically checked.
0 = Germany
1 = Great Britain
2 = USA
3 = Italy
4 = E (?)
5 = Japan
6 = France
7 = Canada
8 = Australia/ ** (?)

Having physically checked I can confirm that my car does indeed show a code, it's "_ _ _ _ 5 1" which doesn't seem to relate to the above list at all!
Can anyone shed any light on this?

Simon

[StewartIngram]

I've just been through a cambelt rebuild (replacement heads etc) and been doing some snagging of various things since then. Without going through lots of detail, I've had a problem with no.6 cyl, now cured (I think, injector and pencil coil were replaced).I'm temporarily running on petrol (normally lpg but a minor fault was corrected today, not yet tested). I'm finding the cost of petrol staggering to what I'm used to! Some of that is due I'm sure to the cyl 6 misfire, and also due to the almost daily top up of fuel, due to tank and gauge problems which I'm now investigating.
Fuel gauge won't show over 1/2 full.
Regular running out of fuel (spare can in boot needed) when less than 1/4 full.
Petrol fumes after filling up. Either misfire related, or leak under seat? Not as bad now as I did have an exhaust leak, now sorted.
Diagnostic tests:
(6.0) --6.0 --0047
(6.1) --6.1 ------
(6.2) 1-6.2 --0039
Resistance checks on fuel pum socket under rear seat:
pins 5 & 2 (pump) 4 ohms
6 & 3 (n/s float) open circuit
4 & 1 (o/s float) 5 ohms

Now to me, that says the float needs attention (already rebuilt the o/s a few months back. That corresponds to the --reading in diagnostics. To me it also explains the max 1/2 tank reading. However, the pre-readings (ie 1, 2 3 )of float status don't seem to stack up. The lack of fuel in the tank is a concern
(to me); the engine stopped this morning and I put in a 4.5L can of fuel, I've done no more than 20miles or so, with a little test idling since changing the injector. I guess that is about right with the misfire I had?
I'm not exposing the tank today as its starting to get dark, a job for the morning. I'm also thinking I may have a problem with the transfer pipe between n/s & o/s; not sure if there are any electronics involved there? Maybe the o/c float can't send a signal to turn the pump on to transfer fuel? It will be interesting to see the level of fuel in the n/s.
I forgot to add, the engine stopped again, whilst idling, not surprising with the low fuel being indicated!

Stewrt

[SD1too]

Originally Posted by StewartIngram

Resistance checks on fuel pump socket under rear seat:
... 6 & 3 (n/s float) open circuit ...

That's your problem Stewart. The two floats are wired in series so if one is open circuit it doesn't matter what the other one is doing.

Simon

[T-Cut]

Originally Posted by StewartIngram

I'm not exposing the tank today as its starting to get dark, a job for the morning.

Hello Stewart, one thing you might check for me when you go back to the tank, is to compare my old drawing of the pump connector with your actual setup.



A recent discussion about tank floats suggests the drawing may be upside down with the 'open' end of the socket uppermost. I'd be grateful if you'd look at the socket layout and pin-out positions.
Many thanks.
TC

[StewartIngram]

I'll post an updated one later in the week when I double-check the details.
I had a go at the filter float; checked evrything with a meter before popping it back into the tank. However something is still adrift so I'll have another look on Wednesday - good weather forecast here (61F)!
I'll also have a look at cyl 4 petrol injector, that comes up now and again with a fault, but on lpg it is fine, very smooth.
I have a brown flexible pipe on the filter in the tank, it doesn't go on to the ribs on the filter too well, any tips? I can't really warm it with a hairdrier!

[StewartIngram]

An update on progress - I'm now confused!
Basically the float rheostat on the filter was beyond repair, so I sourced another. When I received it, it was an early model filter (non-orange clip_ so I didn't fit that, instead I just swopped the rheostat over (a quick soldering job).I also clamped the black hose to the filter with a hose clip as it had a tendency to fall off. I checked the operation of the float with a meter before inserting it in the tank; again after that I checked the resistance at the connecto on top of the pump. In both cases, the reistance was approx 40 ohms, with a small variation each side. When I turned the ignition on, the gauge showed 1/4 tank; tbh I expected more, but it is difficult to judge the level of fuel sitting in the tank, though both sides seemed similar.
However the strange result is from the diagnostics:
--6.0 = --0106
--6.1 _ = ------
2-6.2 = --0091

Any thoughts on this?
A quick drawing of my connections is attached.

I also came across a strange thing with the gasket - I'll keep this to a separate post.

[StewartIngram]

In the last week or two, I've been playing with the filter in the tank.
Last year, or possibly the year before? I also was looking at both the filter and pump. When I finished, I fitted new rubber gaskets as I had a job to get them to seal, so they are at most 2 years old.
Last week I removed the filter, with no problems. Upon refitting, I could not get the ring to fit to the edge of the hole, it just seemed too large. In fact I sliced it, fitted it to the edge, and it was about an inch too long! With the excess cut off, it fitted snugly. I then ordered a new one from DMGRS, and over the weekend it was fitted - perfectly.
The work at the weekend saw the pump removed, with exactly the same fitting problems. I will be ordering another ring. Do they stretch in situ or what?

[T-Cut]

Hello Stewart, you're aware the rubber sealing ring will only fit one way up? They have a profile that fits over/under the lip on port collar.They certainly shouldn't swell to any significant extent. Certainly not enough to prevent the locking ring from engaging the tank port thread using hand pressure. Did you check out the various HowTos?
TC

[StewartIngram]

Yes, aware of the right way of fitting the ring.
I don't want to get too involved in this ring fitting, I'm basically at a stage where that is sorted (almost finished) but is mystifies me. The more important thing that concerns me is my fuel gauge readings.
I had another go today, to try to get to the bottom of the latter fault. Really no change however - though I will add some notes on the ring at the end!
I started with the resistance measurements on the plug on the pump. Readings ok, both sides, fairly low around 15 ohms. This points to both floats working. I then pulled out the filter, reading on the float was a bit higher though it was out of the tank and wedged into position, but gave a reading. I then pulled out the pump as far as I could, with similar results. So I'm convinced the floats are working. Last time I actually moved the arms to check changes, but didn't bother this time. However I did a continuity check on each individual wire, from each float back to the plug, with no faults. Before putting items back in the tank, I looked inside with a torch, to check the floats would go in unobstructed. After refitting, I checked the resistances were as before, replaced the plug, and did the dashboard diagnostics; results as noted on the earlier post.
So I am stuck now. I do wonder if a reset of the battery is needed, as if the body(?) computer has a glitch. I'm loth to do it without advice though, in case something else plays up?

Now, the rings.
I mentioned earlier that the filter ring was 'stretched' and I temporarily cut an inch out, refitted it (perfect fit) then ordered a brand new one which also fitted perfectly. Well I took that ring out today - it was stretched! Compared to another unused one, it was bigger, I had to fit the new one to get it in! That is strange, I've even put the week-old stretched one in the freezer, just to see what happens. If it doesn't shrink, I'll get another new one for the pump side....but like I said, not getting bogged down about it.

[T-Cut]

Originally Posted by StewartIngram

I do wonder if a reset of the battery is needed, as if the body(?) computer has a glitch. I'm loth to do it without advice though, in case something else plays up?

Logic suggests it can't cause anything to get worse - but without doing it, you'll not know.

I mentioned earlier that the filter ring was 'stretched' and I temporarily cut an inch out, refitted it (perfect fit) then ordered a brand new one which also fitted perfectly. Well I took that ring out today - it was stretched! Compared to another unused one, it was bigger, I had to fit the new one to get it in!

It doesn't appear to be made of the corrct material. It's obviously swelling from the effects of petrol and really doesn't seem to be fit for purpose. Where did you source it? Is it branded 'BMW' like the originals?

TC