Issues with EFi crossy

[Panko 2,481]

Ok EFi nuts, please help!

 

I have been having an issue with my XF for some time now, but its getting a heck of a lot worse, and I've decided i really need to do something about it. 

 

The issue - 

When the car is coming off cold start, the engine develops a miss, a big miss. when this occurs, it bumps the idle up, but drops 1 cylinder, and runs like a dog on 5 cylinders. which cylinder, i haven't tested yet. its been doing it for probably 18 months now, but the past few months is becoming so much of an issue i can't drive it while this is happening (it stops after a few minutes and runs normal) I think I have put it down to ignition system. 

 

trying to fault find, in the last year or so I have replaced injectors (which needed doing anyway) rotor button and distributor cap, ignition module (with a genuine Ford NOS unit), currently have another coil the same as i already had, but less work, temp sensor (the one for the ECU) which helped with cold start in the sense it brings the RPM down over a longer period rather than being on a switch going from high rpm to low rpm, high pressure fuel pump (again was desperately needed) fuel filter. 
Its not a fuel supply issue, because the fuel pressure is perfectly fine while this is all happening. Its an electronic issue, and i can only think it will be ignition. 
Later this week i plan to fit new plugs and new coil, but I'm fast running out of ideas as to what it could be  

 

Its also developed an issue where it will occasionally just stall, but not cough before dying, just switch off like I have turned the key off. So any ideas would be well considered, because I have no new ideas regarding this problem 

[LTD083 278]

Hey Panko.

Very frustrating by the sounds of it.

Have you tried another known ECU?

Considering that is the brains of the whole system might be worth a shot.

 

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[Panko 2,481]

Yeah i ran a NOS one i borrowed off sparky dave for a couple months.

[LTD083 278]

And that made no difference whatsoever?

What about plug leads?

 

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[Panko 2,481]

The ecu didnt help in regards to the miss. The car felt to have a bit more power, but that was about it.

 

Plug leads was a thought, but because the miss starts and stops at specific moments, i cant see how leads wpuld cause it, however i have another 2 sets of leads, second hand i could try.

[LTD083 278]

It would be worthwhile ruling them out for sure.

What about the AFM? Have you got a good spare?

 

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[SLO247 1,713]

Can it run without the AFM?

[LTD083 278]

It shouldnt be able to Dan.

 

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[Panko 2,481]

No I haven't got a spare AFM, maybe i should try that. 

And no it definitely can't run without the AFM. 

 

I have just discovered, like 5 minutes ago, that the "engine" fuse in the fuse dox does NOT A THING! if i pull it out while the car is running, it keeps running, and starts fine without it too. 

 

I tried pulling the injector loom apart while it was running, and it did exactly what it does when it stalls. identical symptoms. So i tried wriggling wires around on the looms, and couldn't get it to stall. 

Same with the temp sensor for the ECU, unplug it while its running, and it shows identical symptoms to when it stalls on me. but again, no luck wriggling its wires etc while running. I think the the stalling issue might be a intermittent broken wire somewhere, but where i got NFI. 

The bigger issue is still this horrible misfiring issue. 

[Thom 6,651]

Check where the lpg wiring used to be you might have a bad joint

[Panko 2,481]

yeah exactly my thoughts Thom. There is a wire in the injector loom that they broke and tapped into for the fuse and LPG solenoid, which i had to re-solder join together. i have checked that, and that join i put in seems to be holding up ok, BUT, somehow that engine fuse is still bypassed. 

I suspect that wherever that bypass is for the fuse, maybe the bad join thats causing the stalling

[Crazy2287 1,886]

So it stumbles and farts about when it's cold.
is your timing set correctly? What condition are your plugs in?

 

Hows your economy when it's running? should be <14lphundred on highway.
Check AFM meter, I have not run a stock EFI system for YEARS now but I'm pretty sure the IAT sensor is inside the AFM. you can confirm correct operation of both AFM and IAT using a multimeter. But if it runs fine when warm it's unlikely the AFM, morlikely the IAT, CLT (you said you already replaced it), Timing, annnddd... thats all i can think of right now.

For shits and giggels you should measure the voltage across your battery immediately after starting it too, Make sure your getting >13.0v <14.4 you should take this measurement while the car is still playing up.

[Mr Polson 10,214]

Plug leads was a thought, but because the miss starts and stops at specific moments, i cant see how leads wpuld cause it, however i have another 2 sets of leads, second hand i could try.

 

Bad or weak plug leads can cause weird issues in cars. As Jeremy said eliminate them for sure.

 

I have just discovered, like 5 minutes ago, that the "engine" fuse in the fuse dox does NOT A THING! if i pull it out while the car is running, it keeps running, and starts fine without it too. 

 

 

That's not unusual. My wagon is the same. I was going to run my immobiliser through the engine switch in my wagon but as you said, it seems to do nothing on the EFI models.

 

On the carby engines it controls the fuel cut off solenoid in the carburetor.

[Panko 2,481]

So it stumbles and farts about when it's cold.

is your timing set correctly? What condition are your plugs in?

I set the timing when i replaced the module last year, but my timing light has since shit itself. Plugs seemed fine when i checked them, but they are LPG plugs, i just never got around to replacing them.

 

Hows your economy when it's running? should be <14lphundred on highway.

Haha try 9.5-11L/100km on the hwy, 13 around town

 

Check AFM meter, I have not run a stock EFI system for YEARS now but I'm pretty sure the IAT sensor is inside the AFM. you can confirm correct operation of both AFM and IAT using a multimeter. But if it runs fine when warm it's unlikely the AFM, morlikely the IAT, CLT (you said you already replaced it), Timing, annnddd... thats all i can think of right now.

For shits and giggels you should measure the voltage across your battery immediately after starting it too, Make sure your getting >13.0v <14.4 you should take this measurement while the car is still playing up.

I did clean the AFM last year with proper aerosol cleaner stuff, made a difference in the way it drove, but didnt help the miss.

 

Volts are all good. Well should be, i have both the normal digital volts guage in the car, and an aftermarket analogue VDO volt gauge, which reads about 14.1V all the time.

[PRO250 1,506]

.......
 

[tpak addict 1,909]

I would do a compression test... one when its cold and another when its at temp.....

As you know things warm up and expand under heat..... 

[Panko 2,481]

I would do a compression test... one when its cold and another when its at temp.....

As you know things warm up and expand under heat.....

 

Well i havent done for a while, but i do know it was pretty average last time i checked. But it does have 325,000km on it untouched.

 

Another theory i had, which i want to seek views on.

When i had the gearbox replaced recently, the transmission shop told me the head gasket was leaking slightly at the back of the head, dropping a bit of coolant, which i have no seen for myself. Could there be a chance that under certain pressures as the engine warms up, the head gasket is spraying or leaking a bit of coolant into the cylinders, or 1 cylinder, causing the engine to missfire until it either builds up enough pressure or temp to seal the leak, or it dries whatever coolant out and starts to fire the cylinder again.

 

I stuck my inspection camera down all the cylinders recently when i checked the plugs, and it appeared there may have been a slight bit of something seeping into a couple of the cylinders where the head and block meet, from the passenger side of the engine. However,my camera wasnt clear enough to make out what it was. Also the pistons looked very dirty on top, or crusty, but again couldnt make it out.

[tpak addict 1,909]

Thats possible and why I said do a compression check cold & hot.....

 

Maybe at that time for a reco....

[Panko 2,481]

Thats possible and why I said do a compression check cold & hot.....

 

Maybe at that time for a reco....

Hmm ok maybe its worth a shot.

its still very much an electronic (or would appear to be) issue, very distinct when it starts and stops.

 

Im screwed if the engine is up for a reco. I cant afford that lol. Just had the gearbox done, and now the diff has gone, definitely hadnt planned on building a motor.

[tpak addict 1,909]

Always the way tho.... I am lucky as I have spares for mine and against the wife insistance will not part with my spare running gear for just this reason... Its nice to know if anything does happen I have a backup plan... I know when the FG trans shit itself that seriously hurt the wallet (lucky its only a 4sp not the 6sp)

[Panko 2,481]

Well i have another engine, but in bits lol. The other engine was always intended for the turbocharged build, which im certainly not ready to do, with the other turbo wagon build already on the go.

[tpak addict 1,909]

Aww that sucks.... My plan was to slap the other engine in and rebuild the original engine faster, stronger than before... 

[Panko 2,481]

I dont think compression is the issue.

 

[PRO250 1,506]

111psi is fubar, most crossys no longer run on all banks that low and would also be the miss it has

I would not be chasing issues till you fix that the engine is never going to run any good as its about dead 

and im very surprised that engine does everything you say it does cause that's dead as far s a crossy goes mine had more comp then that with 2 broken comp rings and a side off a piston and it still run on 6cylinders like that was just a chugger out the breather pipe as it would just blow the comp past the rings into the sump

a happy good stock crossy has around 180PSI across the board a few PSI drop is fine as theres a fair bit to a engine, but that things 28psi down from 1 to 6 id almost say the engine had a broken comp ring on 1 being that low or a rather large valve issue

I have a 120.000km crossy in the shed no head $250 if you want it, fit a head (little dave will sell you a brand new one ill ask him if you want. and a $100 for a gasket set and some valve springs and dump it in the hole

or build a new one. a stock crossy cost very little to build last slapper I did cost $670 and about $400 in bits I already had as I have boxes of crossy bits

RIP little crossy
  

 

 

[Panko 2,481]

Well like i said the compression isnt the best, i knew that. But go back to before it started having this miss, ive tested it numerous times before, the compression hasnt changed much at all, if any over the past couple years. I now run a bit thicker oil, which may explain why i was a little surprised at the reading on a couple of the cylinders, which previously i have thought were worse off.

 

I know the engine is tired, but the fact it runs so well after its few minutes of madness, is why im so confused by it.