High MAP reading

[xsport]

As an aside stewart, do i recall that you had an issue with one of the banks dropping out on one of your LPG ECU systems a while back ? and that resolution was to change the cylinder number to a vacant one. as the system can be used up to 8 cylinder vehicles ? This may or may not be relevent as you are the only one that knows this !!! ... just a thought .....

[xsport]

Another thing you can check stewart , is the plug- in connector to the number 6 lpg injector. sometimes these can come slightly adrift , and not be fully pushed home. They do have a "peg" on the plug itself to hold the plug in once connected , but can come out as the peg is very small that clips them together. Plenty to carry on with for now ...

[StewartIngram]

Well I've dug out a spare pressure module, but other jobs took priority today, maybe tomorrow then.
A point I have noted and wondered about - the firing sequence on RAVE etc always quotes the firing sequence as 6-1-2-3-4-5. I wonder if the monitoring sequence always starts at the 1st cylinder and thus quotes cyl 6? Just a thought....
I have either put my foot down a tad harder, kept it down a bit longer, or maybe have decelerated quickly (comment on this in a mo), and sometimes had bank 1 or 2 faults, but nowhere near as often as a cyl 6 fault. I suspect this is because of a fuel shortage, causing the 02 sensors to react? Incidentally, there is an option to connect these into King/Bigas, but I never have (yet).
I reckon the fault also occurs if I decelerate quickly (say responding to a vehicle in front), this is perhaps because fuel is shut off rapidly but revs are high?
Good to have the confirmation about the cam covers, on the roundtuit list but not desperate!
As I've said before, fault never occurs on petrol Also never in these circumstances switches back to petrol - though it will when the tank gets low.
Also, I have noticed (I think when the engine light has stayed on, as by then I don't be over cautious with the throttle to stop the fault happening) that if I then use a bit more revs, there seems to be a slight misfire that happens like a fuel shortage?
Good idea to check nozzle 6, but not easy without removing the rear manifold (and probably the front as well), but I'll bear that in mind. I think - not sure - that I did check it in the past however.

[xsport]

Dont forget the lpg injector plug 6 checking. The o2 sensors are there to monitor and keep the trims within scope. They are ignored when you put your foot down and when you select a gear in auto. They come into play once the engine revs stay constant, as they cannot provide feedback to an increasing throttle opening or shutting down. I can tell you from my own experience that the king/bigas system only caters for certain ford models with a built in modified ECM for connecting to your cars o2 sensors with this system. I strongly recommend that you dont go down this route , as your trims will go rogue and will cause you much grief. Its a no no . You can set the evaporator to the bar pressure i listed and then work your mapping. You can if you would prefer , have the king app on your desktop on your laptop. You can run it up and reset your mapping in your front room at home and save it to a different name mapping. if you save it you can try it and still retain your present mapping as well provided you name them seperate names/dates. Your first job is to find fault cylinder 6 .you wont proceed until this is rectified. change the spark plug as well,and suspect coil, even if it does seem ok on petrol.

[StewartIngram]

Spark plugs & coils have previously been checked a number of times, by replacement with new, and swapping with another cylinder. Evaporator pressure has been always set (without change) to the recommended setting in the Tinley guide, with no problems originally, until this fault developed. This to me also points to the injector nozzles, particularly no.6, being the correct size. A thought has just occurred that some time back I serviced the evaporator, fitting a new diaphragm as there was a small split in the old one. Was this when the fault started - I don't know. Incidentally, just to clarify terms here; the fault occurs during acceleration, but not heavy footed acceleration, just mild acceleration and allowing rpm to increase to around 2.5k+ and beyond.

[StewartIngram]

Update on the pressure model change. I had a 30 mile trip first thing this morning, then a fence job in the garden when I got back so the car was standing a good while before I got round to changing the module. I did a thorough exam of the surrounding pipes too. I then did a limited test drive only about 2 miles out and the same back; as most of that was in a 40 limit, I kept it in low gear and used higher revs than normal to simulate the 2.5k problem. In fact I reached 3-4k, with acceleration fairly hard up to 5k, with no problem. Looked good, but....
On the way back it seemed to have got into its normal fault mode, light coming on (hough at slightly higher rpm, perhaps 3k) but going out when I eased off . So I'm saying no change really.
Now, the reason I mentioned the car had been standing a while relates to engine temp. It wasn't completely cold when I went out, though the gauge was practically zero. It was almost an instant changeover to lpg rather than the normal 1/2 mile maximum. And, as I said, it behaved. Having turned round to come back, I would say it was absolutely at normal temp. Wild sideways thinking, but is this fault perhaps related to engine (or more precisely gas) temperature.
The evaporator is plumbed in (exactly the same as I've always done it) into the car cooling system. As we all know, the KV6 is a bit of a beast to fill and bleed correctly - I'm well aware of that. I' added the evaporator at a higher position in the water flow, with bleed valves added n the hoses next to it, and they do make it easier. But I do have a slight leak somewhere. I check the level usually on a Saturday morning; every 2-3 weeks I have to top up with a jugful (and yes I do know the correct level). That is a separate issue which I am also tracing, but I am wondering if it could lead to an airlock (maybe partial) in the evaporator, causing a temp change in the gas? So a need for extra gas flow cannot be achieved? I don't know, just thinking sideways and probably totally irrelevant, but I'm open to any idea!
I'll give a rundown of everything I've doen to trace this fault in the next post.

[StewartIngram]

In no particular order, these are the things I have checked (just about all of them multiple times)

Spark plugs checked/adjusted/changed, also swopped between cylinders to
move fault around (but it didn't).
Ignition coils also.
lpg main filter removed, then replaced.
In-line small filter in front solenoid cleaned
Fuel tank drained, to enable fuel pickup pipe and float to be checked and
ensure not trapped internally.
Under floor metal pipe renewed with a new flexible one.
Front & rear solenoids checked.
Evaporator removed, stripped and serviced including new diaphram.
All fuel pipework checked.
All vacuum pipes checked.
Pressure switch module changed.
Injectors replaced - old ones had done around 250k miles, and the
connectors had broken up with age.
When swapping kit to this car, 12 months ago, small hoses to nozzles (and
the nozzles themselves) were checked. In fact the aluminium manifolds were
originally on the older cars, it saved me work in fitting new nozzles.
When doing other work (non-lpg specific) other items are always checked.
(eg normal vacuum hoses, top manifold etc).
Electrical wiring that I have done to install the lpg ecu, fully checked, in
particular the crimp connectors.
Earlier ecu fault I mentioned which was referred to in a post above, sorted
initially by using a spare connection, before changing a relay inside. In fact
the ecu has since been replaced quite some time ago as well.
Software recalibration re-done, though since the first install in 2007, and
subsequent swapping on 3 cars, I have never bothered with remapping,
perhaps wrongly thinking of it as a minor tweaking. Strange that the fault
has then occurred in normal service
And for completeness I never bothered to include the O2 sensors in the wiring (though Tinley recommend this option).

Have I missed anything? Should I check anything in a different way?

[xsport]

stewart . The concerning part to all this is that you are losing coolant. It is well noted that when the alloy manifold to heads gaskets leak, that the outer cylinders suffer misfire. You may have a coolant leak into that cylinder 6 . I would remove the rear bank and clean and replace the manifold gasket.Did you look at the condition of the plug in cylinder 6 ? It should be cleaner than others, but compare it to one removed on the front bank , however its not that straightforward to spot as you run lpg , which is alot cleaner. If you cannot find your leak elsewhere , then this is probably the reason for the loss of water , and your missfire.

[StewartIngram]

Now I've had time to write the above posts, and for the 1st time in absolute ages I've concentrated on this particular fault, I've had a few serious thoughts.
Firstly, I've got the water leak. As I've intermittently looked at a similar fault on the old car, which I never did fix, I found the new car rather pleasant as it had no leak!. However, with the small leak I presently have, I really think is not a big problem, a little concentration and it will be sorted. I have nothing visible under the car. I do have odd traces of antifreeze around the hose connections on the evaporater connections, this I believe to be the most serious issue. (I have thoughly checked elsewhere and know other things such as manifold gaskets, filler cap, you name it, are definitely ok. I think also the filling procedure is not 100% right; remember the extra plumbing that has been done? Trying to manually bleed even with the extra bleed valves is not easy - I prefer to vacuum fill but my equipment has not been available for a while. I can sort that out (amongst the million other tasks I am involved in of course), and then fill it properly as I always used to. It is a fact that if not bled right you do get extra leakage, as I know from experience.
Then the lpg/cyl6 problem. After racking my brain to compile the list of what I have already done, 2 things stand out to me. (a) the water leak mentioned above and (b) the fine tuning after calibration. I've read & re-read the Tinley guide, it is well described but impossible to do properly without an added driver. I'm investigating how in the coming days, and hopefully will arrange this. The Tinley guide actually refers to adjustments for the acceleration condition of my fault, and also the rapid deceleration fault as well. It seems a no-brainer to not tackle these adjustments, just hope my driver is willing to help (He is also a 75 owner). Strange that I've never had to do it in past years though. And following on from that I will probably add the extra lambda wiring in, to see what difference it makes (it can also be removed if necessary).

Watch this space....

[xsport]

stewart. You have king on your laptop dont you . Can you run the system up and select load map. It will come up with your present map. can you take a photo and send me a screenshot in a private message. ? or i can give you my email address to send it to me. You can do this in the house not connected to the car. just click proceed without connection and select your current mapping. I would like to see it , and suggest maybe what is wrong ... if anything.