Idle

[Greydog]

OK fuel pressure is OK Injectors sound and from the sound of it no issues with the crankcase ventilation

Good luck finding the issue Henry weather is better today so maybe if you get time the hunt will continue

[henrym3]

Just to keep an update. I have replaced the MAF and now don’t suffer from stalling but it still has a bad idle. BTW £49 for Bosch MAF. Obviously I’ve been doing some reading and if we go back to the fuel pressure test which was 3bar with ignition switched on and I assumed that was ok, I never mentioned that I started the engine and it was 3.5 bar and my reading says this shouldn’t happen and the pressure should remain at 3 bar and be regulated at that by the FPR. So next step is to smoke test again and pay more attention to the vacuum line which runs under the vehicle. Not easy as they are behind plastic. But hey, what else has a retired bod got to do.

[Greydog]

Progress Henry, at least it looks as though we have a few days of decent weather while the "old bloke" is rolling around under the car
I fit comfortably or sometimes un-comfortably into the same category These days it often takes longer to get up than to do the job

[henrym3]

79110839-64E4-456A-8A92-79B6D9C7EF56.png (39.06 KiB) Viewed 550 times

Some progress, got the smoke kit out again and initially there was nothing but as I’m using a bicycle pump to pressure the system I thought I needed to be closer so recruited the wife to pump while I fiddled and wobbled pipes. As soon as I touched 11 I got smoke. So replaced that and now have excellent idle and no stalling on petrol. So need to have a rethink/design of my smoke machine. LPG is still rough on idle but fine when moving. I also notice that the the idle on LPG is only around 550 rpm and lower and rougher when sitting in gear. So, anyone know how I can increase idle on LPG to the same level as it is on petrol. My reading suggests that the mixture is to lean at idle. On preview I see the item numbers don’t show. It’s the wobbly pipe.

[Greydog]

Morning Henry
Great news on finding the culprit
What about using a tyre inflator or spare wheel to give a more constant air supply for your smoke machine. Probably need some sort of pressure control if using a spare wheel
Maybe need someone who can check the LPG ECU and adjust things there ?

Dave

[henrym3]

You’ve pissed me right of now. Why didn’t I think of the tyre inflator, I’ve got one. As for finding someone to plug into the ECU is difficult. The Polish guy who used to do it is gone. Dorset LPG are close by but very expensive so they are a last resort. Another week of fiddling and then I’ll have to bit the bullet.

[Greydog]

A friend of one of my sons brought an LPG diagnostic program from Ebay same issue as yourself the guy who installed his system (Prins I think) has gone and the next nearest wanted a useful body part to even look at it.
He paid around £40 for a Disc and interface cable sorted his problem just by resetting the software. Might be worth a look to see what's available
Dave

[henrym3]

I was fiddling again today and while the vehicle was idling I was just feeling pipes and whilst the coolant pipes were well hot the ones going to the vaporisers x2 were cool. So suspected an air lock. Bit more investigation found the auxiliary water pump not working. Stupidly I clamped the hoses and then removed it only to find that when connected to a battery it worked. Long story short pin 9 on the HVAC supplies the voltage or not in my case. So have rigged up a line on a switch to supply the voltage. Run the engine to working temperature and all pipes are hot plus the LPG idle is vastly improved. Haven’t that long finished so will test tomorrow.

[Greydog]

Thats interesting I have been getting an intermittent issue with the Aux Pump not running first showed on my monthly scan of the car. Maybe I have a faulty HVAC unit
Good luck tomorrow
Dave

[henrym3]

Petrol idle is fine LPG is not as good but perfectly acceptable, I should have known to look at the aux pump as for a couple of days I’ve had odd heating issues ie passenger side cold drivers side hot or vice versa. Apparently it runs permanently up to 3.5k revs and then shuts off as the coolant pump has enough ooomf to circulate the coolant properly, so make sure you stay well north of 100mph so as to reduce heating issues Good luck if you have to change it. PITA.