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Please go back to the original problem of water in the fuel system. That is the basic problem.
You did get it started for "one glorious minute" and then it "cloncked out" again.
Later on after spinning it over with the spark plugs removed then refitting the plugs it started again and then stopped.
I believe you still have water in the system. You are clearing the cylinders and putting in dry plugs and almost immediately it starts but then stops.
What I would do is
check that you have a couple of gallons of gas in the fuel tank.
Throw in a quart of methanol. I believe it is readily available in speed shops in the USA.
Set the gear selector in any position other than park or neutral.
Turn the key to start and hold that for 5 minutes ( alternately jumper a battery lead to the fuel pump so it is running continuously) Gas will run through the system as well as the methanol and be returned to the fuel tank. It is a continuous flow system
That should flush the system and mix any water with the methanol which will burn in the presence of petrol.
Then again remove and dry the plugs, spin the engine over on the starter until satisfied the system is dry, replace the plugs and try again.
I have had to do this on one occasion in my sons S3XJ6 as no amount of blowing with air hoses could clear the fuel lines of water.
For Australians you can substitute "methylated spirits" for methanol. I don't know what is the equivalent in the USA. (Methylated spirits is a rough mixture of ethyl and methyl alcohol commonly used for cleaning and antiseptic properties)
Bill Mac
MK1
MK2
S3XJ6
X300
15 previous Jags MK5 to X308
Yes. I came to the same conclusion. But I want to see water. In the beginning I pumped all of the gas out out the tanks through a clear glass pickle jar to see if water was the problem and it was.
Put fresh gas in the tanks and tried to start with no luck. I thought that I could clear any water from the system just by cranking and cranking. Still no luck starting.
Instead of putting methanol in the tanks (but I did add "Sea Foam"), I opted to replace the existing filter with a fuel water separator, so I could see any water.
There was water in the existing filter.
I have got a jumper on the fuel pump relay, so the pump comes on whenever the ignition is on.
Left the ignition on for a few minutes.
AND IT STARTED.
No water in the separator, rather surprising but good news.
Runs rough, but it is running.
So still work to be done, but it is a major step in the right direction.
Thanks to all, for your suggestions.
Will keep posting updates.
jpipe
Hoo bloody ray!
I am happy that you returned to the basic problem/cause of water in your fuel system
Too many times people lose sight of the original problem and drift into unrelated areas.(ECMs etc.)
I still advocate you use the methanol/methylated spirits additive to get rid of any lingering bits of water in the system.
I am not conversant with "Sea Foam". Is it a similar product?
Now get it onto the road and give it some serious throttle bending to blow the cobwebs out!
Bill Mac
Primarily used for outboard engines as is the water fuel separator.
Reading the label, looks like a cure all.
Thanks.
PS "give it some serious throttle bending to blow the cobwebs out".
The last time I did that, I got a big speeding ticket.
jpipe
You have to pick your spots to avoid the dreaded speeding ticket
re, sea foam
Not quite what I had in mind, Sounds good but I am looking for the alcohol/water pickup in flushing fuel lines.
Another alternative would be to put a couple of gallons of fuel with 10% ethanol mix straight from the service station through the engine.
I hate ethanol blended fuels and at least in this country we can still avoid them as pump outlets must be clearly branded with octane and ethanol etc.
My contacts in the motor trade reckon ethanol blended fuels cause serious problems. OXY sensor premature failures and corrosion in fuel systems are problems they encounter
But in this case the ethanol would be useful in purging water out of your fuel system.
You mentioned the engine was running "rough". I suggest you check your spark plugs for ceramic insulator cracking.
A sudden injection of water after the engine ran for "one glorious minute" may have stressed the ceramics.
Bill Mac
A fuel conditioner called HEET works pretty well by mixing with the water and allowing it to flow through the injectors with the fuel. I wouldn't use it on a long term steady basis, although I used to add a pint every winter for years. Use the "red" container not the "yellow", much gentler on rubber parts.
Thought I would post a couple of pictures of my setup so far.
My Fuel/Water Separator:
My Fuel Filters, one for each tank:
Today, I have been monitoring the fuel system.
The pump relay is "hot-wired", so the pump comes on with the ignition.
As soon as I have fuel pump running, there is 40 psi at the fuel rail.
If LEFT tank is selected, I can hear return flow, but there is NO pressure build up (no woosh when opening the fuel cap).
if RIGHT tank is selected, I can hear return flow, but there IS significant pressure build up (lots of woosh).
I don't understand why.
I am in trouble (from the wife if she finds out), the cap broke off on the right tank. I can't get the insert out the tank. It is stuck fast. I just clipped the cap back carefully and wait for her to open it.
Any quick fixes?
Occasionally, the brand-new fuel pump does not start without a quick tap on it's housing. There is always about 11.5 volts on the terminals.
John, what do you mean exactly when you say "there is always about 11.5 volts on the terminals"? Brand-new fuel pumps shouldn't need to be tapped on their housings to get started. Could it have sucked it some crud from the tanks already?
When the ignition is ON.
I measured 11.9 Volts at the pump with the pump disconnected.
When the changeover valve (fuel tank selector) is ON, I measure 11.5 volts. OFF, I measure 11.9 volts.
When the pump is connected but not running (stalled), I measure 11.5 volts.
When the pump is running, I measure 10.0 volts.
The battery is new and kept fully charged with a charger after each cranking of the engine.
Those filters are new and were installed before the pump, so no crud. Might have been left over in the lines between filter and pump, but I doubt it.
The changeover valve was replaced after the pump when I noticed it had failed too. So basically, everything is new.
I did however notice very fine "dust" particles in the water/fuel separator when I drained it, looking for water. I think that was residue from previous installation.
No water, but murky looking and smelt almost like fresh gas. I think the "sea foam" is doing it's job.
More Questions Than Answers. Today, I have been checking the wiring.
In trunk, next to the ECU are these.
What are they all?
Note Like the component on the top right. There three of these. Each one looks burnt at the top left side of the component (above the red wire).
ECU: I have been measuring voltages/resistances at the ECU using my wiring diagram above.
Most of the wires check out, except the connections to the Throttle Switch (310). No connection here.
Found the Throttle Switch and took off its connector. Although there are three connections on the switch, only two wires are used (to the ECU).
These two are open circuit when tested at the ECU. The color of the wires at the switch don't match the colors at the ECU.
What am I missing here?
the black box is the oxygen sensor milege counter, it is re-setable. Usually the dash light comes on at around 40k miles to remind you to go spend money on a new and useless O2 sensor. Just push the reset button on the side of the box and forget it.
the little silver boxes with 3 wires are the "hey you got a bulb that burned out" sensors.
The black box marked "XK 4.2 6 cyl" is the interface unit for the trip computer. This takes info from the ECU and converts it to a language the trip computer can understand to calculate your fuel economy.
The device Jose mentioned is known as the Intervalometer. It looks like this:
But don't bother looking for it as your '87 will not have it. The last year for this device was 1986.
More Questions Than Answers. Today, I have been checking the wiring.
ECU: I have been measuring voltages/resistances at the ECU using my wiring diagram above.
Most of the wires check out, except the connections to the Throttle Switch (310). No connection here.
Found the Throttle Switch and took off its connector. Although there are three connections on the switch, only two wires are used (to the ECU).
These two are open circuit when tested at the ECU. The color of the wires at the switch don't match the colors at the ECU.
What am I missing here?
I think all you're missing, perhaps, is a better diagram. Do you have the S57 wiring guide? If not, PM your email and I'll send it to you. Or I think Jose has it on his webpage. I think the diagram you're using is based off of a very early Series III and doesn't show the changes made in later years
The S57 shows yellow/red and yellow/white at the throttle switch. The YW goes to pin 18 of the ECU and the YR goes to the Air Switching Module. A yellow/black from the ASM goes to ECU Pin as a full load signal.
ooops sorry bout that John. I spoke too fast about that black box.
yes you can download the S57 Wiring Guide from my website, and any other documentation needed.
maybe Doug agrees that 1987 thru 1992 Series 3 XJ are poorly documented, whether 6 or 12 cylinders. Not to mention the radio wiring from 1985 thru 1987, another confusing subject.
jpipe
A fuel pump that needs a tap to get it started is an indication of the pump mechanism getting clogged.
It is nothing to do with electrical problems.
The parallel windings systems in these sort of electric motors (even though they have permanent magnets) don't have any torque at start, unlike series wound motors like starter motors and window winders
The slightest binding in the pump mechanism will make them stall
Very fine particles can pass through the filter at the input to the pump and will build up in the pump area causing it to bind and giving it a tap generally loosens it enough to get working
I have experienced this several times over the course of 30 years ownership of S3 cars by myself and my son. The "fix" is to reverse flush the fuel pump by making it run backwards.
I have done this by removing the pump from the car and connecting the inlet and outlet line fuel lines via fuel hose to a glass jar full of fuel. (I don't want to risk a fire in the boot)
I then connect the original earth lead of the pump to the positive terminal of the battery and the input (positive) lead to the negative battery terminal
This will then have the pump sucking back from the original outlet and pushing fuel out out of the original inlet.
I have always been surprised at how much "crud" I have discovered after this sort of flush..
Since then I have always incorporated an inline fuel filter immediately prior to the fuel pump with no further problems of clogged pumps.
From your previous posts I think you have this problem even though you have a new pump. I suspect it copped some "crud" while endeavouring to get the car sorted out.
Bill Mac
MK1
MK2
S3XJ6
X300 (X2 don't ask!)
15 previous Jags MK5 to X308
Doug & Hose.
Excellent information. Love the explanations using "short" and "long" words. Very understandable.
Been using the wiring diagrams from the manual and AJ6Engineering.
Thanks a lot.
ooops sorry bout that John. I spoke too fast about that black box.
yes you can download the S57 Wiring Guide from my website, and any other documentation needed.
maybe Doug agrees that 1987 thru 1992 Series 3 XJ are poorly documented, whether 6 or 12 cylinders. Not to mention the radio wiring from 1985 thru 1987, another confusing subject.
Agree 101%...except I think the poor documentation is much broader than just 1987-1992 !
11-04-2021 | 08:57 AM
