Yes, there were a number of issues resolved today.
1) LPG Evaporator had been constantly freezing.
Upon close inspection, it is clear that whichever monkey plumbed in the Vaporisor, for some reason forgot there was such a thing called gravity, and expected water to just "jump" up through an upwards 90 deg vertical bend to feed the evaporator. In short, evaporator had no coolant flow, hence why it was always covered in ice when driven on gas! We resolved this by removing half of the cooling system, and re-plumbing it. We ditched the majority of the "T" peices, cos they are totally un necessary. The coolant feed for the evaportator is now coming directly from the coolant bridge, and the evaporator feeds the coolant hot back to the HBV. This way, the evaporator is constantly fed with hot coolant - yet the HBV can still do it's job. When we put the inlet and plenum on and fired it up - Instant difference - evaporator red hot. So that problem is now solved.
2) Original air intake pipes (bagpipes) were a pile of poo.
They were badly fitting, and clearly not capable of being air-tight. All of the gas unions were not sitting properly in them, resulting in potential leaks and verging on unsafe I guess. Existing LPG Pipework was too long with kinks everywhere - a real mess. We resolved this by fitting a completly different set of bagpipes, from my V6 LPG breaker. In the process, we considerably tidied up all of the gas hoses, shortening the excessively long ones to remove kinks, secured the ICV to the plenum, tightened up all of the hoses, and clips so it was all tidy, air/gas tight and totally secure.
3) Monkey had attacked the throttle bodies.
We also noticed on a previous occasion, that the reason for the high idle was that a monkey had forced a screw into the butterflies to keep them open. This resulted in an increase of about 700 rpm, and failed the emissions test at idle (naturally!). We resolved this simply by popping off the throttle bodies, and removing the screw! Hey presto, idle was where it should be.
4) Intermittent coolant leak fixed. Once we'd taken the plenum and inlets out, it was clear where it was coming from. Big split in the pipe from bridge to HBV! This was removed, and binned, following our re-plumb.
5) LPG idle problem!
At first, I was convinced it wouldn't idle on gas because not enough LPG was getting into the ICV, and the petrol injectors were turned off, hence the engine would be starved of fuel when the throttle bodies were shut, and hence die.
Turned out I was barking up the wrong tree though. After much head scratching and testing various things, we got to the bottom of the gas idle problem. When poking around the vaporisor, I saw that the earth for the gas solenoid wasn't making contact. Do'h! Reconnected this, and (following the replumb) it now idles like a song on gas, at the correct RPM. Result! We also filled the gas tank - didn't want to overlook the obvious (and I didn't trust the LED gauge), so had to eliminate no gas as a cause of bad running!
After doing this work and filling it up, A long test run on gas demonstrated no problems at all. No poor idling, and believe it or not, less hesitation on gas than my new sequential system. For a mixer, I'm really impressed with how well it's running on LPG. (Tunnie, your face was a picture at the BP garage, when you removed the gas pump and the excess gas came out with a whoosh
)
I feel that the connection of this earth is dodgey, so this will be soldered on the next visit.
Unfortunately, the problem with the lifter is still there. Listening to it, I'm pretty sure it's only one lifter. Now, Tunnie has done over 700 miles in this car, and it goes really well, so I personally am suspecting it's just an unfortunate lifter failure, rather than an oil pressure problem.
Our plans from here, are to strip the top end, all bar the heads, pop the cambelt and camshafts out, and remove the lifters. We can then check them out one by one, and replace any dodgey ones. I'm pretty sure the failed one is on the passenger bank. We're going to try and blag a couple of known good lifters from Mr DTM
Once we have done this, Tunnie will have a very sweet running Facelift Elite 2.5 V6, with a perfectly working LPG conversion, and an almost full MOT.
From there, we just need to rectify a few very minor niggles, and the job's a goodun.
Otther issues to work on are the speedo being intermittent (resulting in loss of servotronic PAS), multirams (I can see one actuator is bust)... and a few little bits.
The EML is on, on petrol only. The only stored code is 46 (Air pump relay High voltage ) so will research this.
Although we have re-plumbed the cooling system, I have had to "bodge" a couple of pipes where we could not remove the T's (eg, block a couple of excess pipes with a bolt and jubilee clip
) - to rectify this we need a couple of manufactuers pipes, as generic won't do. But this is a ten min fix and can be done when we strip it to get to the lifters.
I also noticed that the airbox is missing it's feed pipe, so it's taking in slightly warmer air than it usuall would from the intake at the front. So another little thing to tweak.
I think it's about time this project was put to bed, and I'm hoping for a few days off week after next, so Tunnie - I'll PM you some dates tomorrow and we'll take it from there.
There is now a lot of light at the end of the tunnel for this car,
Author
Topic: big, big, BIG thanks to JamesV6CDX (Read 2857 times)