Perhaps a faulty temperature sensor or similar?
Yeh i couldnt see anything specifically broken, but that sounds likely!
I just bought cotton overbraided fuel hose, as thats what was already on there. I'm not a fan of large bore silicone for vacuum purposes. It gets soggy when it gets hot and can be sucked flat as theres no reinforcement.
Spent a good bit of time on the P38 this weekend. Weather was crap so lots of rain dodging.
Felt like lots of partially completed jobs, but progress nonetheless.
Got the steering track rod swapped out, but still need to take it and get the tracking done.
Got the LPG injectors changed as per the other thread, but not working properly.
Did some testing on the cruise control. With the pipe to the cabin blocked off, i powered the pump and ensured the pump and solenoid was working properly. All fine. Connected the cabin pipe back on and it stopped pulling a vacuum. Disconnected the pipe from the switch on the brake pedal and blocked the end and it still wouldnt pull a vacuum, so i've ordered a new length of hose and will resume testing once i get that replaced. At least i know the pump and diaphram are good.
Inspected the AC condenser, and it looked ok. A bit crusty, but no obvious corrosion at the top edges, so i hope that'll just need gas. Will find out when it goes in for alignment etc.
Dropped the engine oil and replaced with 5w40 (it had 5w30 in it that i'd put in as a bit of a flush). No issues there.
Decided to have a look at the Autobox, so dropped the sump off that, and put a new filter in and refilled with oil. Unfortunately i'm about a litre short, did the level check with the engine running and the level was just on the pip on the bottom of the dipstick. So need to get some more oil for that!
Dropped the oil out the front and rear diffs and refilled with EP90. No issues there.
I wanted to do the transfer case as well but obviously the lack of ATF knocked that on the head.
All in all a reasonable bit of progress, just annoying that theres a few things that arent finished!
Okies, so i got some time today finally, and got the LPG injectors fitted.
Couple of issues.
First of all i got the T-Piece linked above, however i notice that the resistance of the sensor is different to the original one, and there doesnt seem to be any calibration options to change the sensor within the software? Is it close enough to work ok?
I fired it up with the temp sensor disconnected, got the software working (eventually, its shonky as fk) and warmed it up a bit, then hit the gas button and let it switch over.
It ran and didnt have the horrible vibrations that it had on the old injectors, but the engine wasnt happy, wouldnt rev, Spitting and popping etc.
I noticed that the gas pressure was showing as 1.6bar, so wasnt sure what to do about turning it up as suggested earlier.
I figured it was lean due to the smaller injectors, pondered how to fix it and decided to press the autoconfig option within the software.
It asked me to rev the engine at 3000rpm for a period of time and then said it had completed the calibration. After that the engine ran much better, revved cleanly in neutral etc. However when i took it out on the road its not right. Spluttering and generally unhappy at various points in the rev range.
I compared the map before and after, and took some screenshots, i'll post them up shortly.
Any thoughts?
I presume the blend motors are a dash out job? If so thats not happening any time soon :P
Looking at the wiring diagram, the clutch is in series with the pressure switch, so the switch being open will certainly give that fault code.
yeh that was the plan, they're just round the corner and i'll get them to do the tracking once ive replaced the track rod anyway.
I had a look today with the nanocom and there was a few codes:
I think the compressor clutch code indicates that the pressure switch is open?
So we plan to drive the Range Rover to goodwood at the end of the month. I've done a few local trips of around 80 miles and thus far it seems fine. Theres a slight drone on lifting off the throttle, and a bit of vibration at certain road speeds that i'd like to sort out, i guess i'll start with wheel balancing.
Before we go theres some bits i want to get sorted out, like getting the LPG working! and fixing the shonky track rod end, but those are in hand and i mostly know what i'm doing there, hopefully get onto that this weekend.
However the two bits i'm not sure about are the cruise control and aircon. Neither are critical ofcourse, but both will hugely transform comfort levels on a long trip, AC especially if its hot!
Are there any common faults with either that i should look at?
I scanned the HEVAC with nanocom a while back and i'm sure there was a fault code for low pressure, though i cant actually remember (i'll scan again later). I dont think theres any way to scan the Cruise control system though is there?
When i get the alignment sorted i plan to ask the garage to attempt to gas up the AC system. Which i guess will either work, or find a huge leak... The AC condenser behind the grill looks pretty corroded, but i dunno if it will actually be leaking or if it just looks rough!
The cruise control system i've had something similar in an older Audi, and remember they were a pig to diagnose as there was no diagnostics and about a million different things that went wrong with them. The ECU's also packed up, and the P38 ECU looks pretty similar to the one used on the Audi so its probably the same boat. I remember for the Audi someone wrote a bit of a guide showing various things to probe, which attempted to narrow down where the issue was. Is there something similar for the P38?
Cheers
Kev
FWIW, in VAG circles its super common for aftermarket sensors to act wonky and its one of the items thats a firm "buy genuine" (along with MAF sensors!)
Hopefully your new new sensor is ok though!
Have people used the proper P38 diagnostics kit? Generic scanners dont work on these cars.
i went with 30 all round.
Dont get why the rear pressure should be so high? Maybe if its carrying lots of weight or something?
yeh too big and it ends up droning though. I quite like the rasp! Oddly it only does that when revving it in neutral. When driving its a much deeper noise. You can sort of hear it at the end, unfortunately the wife stopped the video right as i opened the throttle!
The rear pipe is 2.5", the midbox is 60mm, and the downpipe is much smaller with a really nasty Y collector on it. I will eventually replace the mid section with 2.5 to match the rear. The downpipe niggles at me at i really want to sort it properly with a decent collector thats not horribly restricted like the factory one, but its too much work for little gain i think.
It also still has cats, and i doubt we'll achieve maximum V8 noise with those still present, but i dont really want to take them out as its MOT/Emissions hassle i dont need.
My end goal is something civilised but with a distinct V8 note though. This is just an interim step for a bit of fun. Once i get a new middle box and figure out how i'm fitting it it should be a bit more sensible.
yeh its not quite muscle truck territory, but its pretty decent!
haha! Yeh, the other one i've seen with welding is folk cleaning parts with chlorinated brake cleaner. If theres any residue, when heated it turns to phosgene gas. I'm not sure the stuff we get here in the UK has tetrachloroethylene in it, but certainly in the US it comes in both flavours.
http://www.brewracingframes.com/safety-alert-brake-cleaner--phosgene-gas.html
Managed to get the backbox refitted earlier and fired it up. No leaks first time which was pleasing.Took a short video after a test drive:
https://www.youtube.com/watch?v=-LsUKMUO7XM&feature=youtu.be
The noise is interesting, from inside when driving its quite deep and boomy, but only when on the gas accelerating, cruising along is quite civilised. From outside when revving it, it sounds epic, like some sort of muscle car. Clearly its too much for daily use and it'll get fixed properly with a new centre box at some point, but it certainly puts a smile on my face :)
If we can end up with as much of the muscle car sound as possible, but just trim out a bit of the deep booming inside the car, that would be ideal. I suspect that dampening the deep boom will also kill some of the v8 rasp though :(
full stainless for £200 sounds bargainy, not found anything remotely close to that, was that new?!
Theres some on ebay for £250ish, but they're only mid/rear and only for dual silencer cars.
When i looked at the exhaust, the rear box was fairly small and is a straight thru design anyway. The middle box is huge and uses a reflection design where the gas bounces around and changes direction numerous times inside. As a result the general concensus seemed to be that the mid-box is doing most of the silencing, and is the one to change as it frees up the breathing as well. But then my rear fell apart anyway, so i figure i do both.
Exhaust place online has suggested a 6x15" box to replace the middle i think. Not sure if i weld it in myself, or pay someone to do it though. I've only got mild steel wire in the MIG (hence painting all the welds), and trying to sort the exhaust alignment on my own while laying under the car isnt easy!
I'll try to make a recording. I suspect it'll sound much worse on video than it does in real life, they often do! Camera phone mics just arent upto capturing such sounds!
First i need to finish reinstalling the backbox. I repainted it yesterday afternoon and left it to dry, but the wife was out in the evening and by the time i got the wee man to sleep it was too late to go start trying to fit the exhaust.
Just trying to decide how large a middle box to buy. I dont want to go too big and over-silence it again, but at the same time i dont want a sore head on the motorway!
both heaters are faulty anyway, so just feed it two new sensors and save the messing about!
I knew i'd need to replace the P38's exhaust ever since buying it. It failed its first MOT on major exhaust leaks from a hole in the rear box and a big leak from the flange between the downpipe and midbox. I'd stuck some epoxy putty on there to get it thru the test and started looking for replacement bits.
I wanted stainless and cheap. Not an easy combo. Kept my eye on ebay and found this:
Not ideal being straight piped, but cheap at 50quid and despite the listing not mentioning it, looked like stainless steel. So took a punt.
It arrived and seemed fine, so i decided to sort it out with a silencer. I had a stainless mid box that i'd removed from my brothers 320d BMW when he upgraded the exhaust, and figured it would fit nicely.
Removed old the rear box, it literally fell to bits:
Then dug the small silencer box out the garage and welded it into the rear of the new exhaust, had it on and off the car about 6 times getting the alignment right, but got there in the end:
I also had a nice tailpipe from an Audi A6, so carefully aligned and welded that on:
Having got to this stage i had a working back box and was quite pleased, but the mid box needed attention. The front flange was leaking, and there was a hole rusted thru it beside the hanger, which had got much worse with all the hacking about thus far.
I decided to get a bit silly, and so used a bit of the old backbox pipe, to create a streight thru mid box. I plated over the hole in beside the hanger with some scrap steel (not shown in this pic, you can still see the hole):
Having examined the front flange, i realised it was leaking because the round part on the downpipe side had crumbled away. After scratching my head i found an Audi exhaust clamp in the garage. These are nice, as they're designed to sleeve over the pipe and clamp on. So i cut the remains of the busted front flange off and set about figuring out how i can use the clamp.
The clamp was designed for 65mm pipe, but the downpipe was 55 and the silencer was 60. Luckily i had some pipe kicking around so sleeved the box and downpipe up to 2.5" to accept the clamp.
I didnt get it fully finished, as i took the backbox back off to paint up the welds to protect them, and proceeded to drop the damn thing on the ground and get the wet paint covered in mud.
So maybe tonight i'll repaint it and get the backbox re-hung.
It is LOUD. I only took it for a quick spin around the block, and that was also before i fixed the leaks. As expected really, my plan is to get a stainless mid-box for it as well, so i'll have it apart again at some point to sort that out, and that will make it somewhat more sensible. In the mean time i figured i'd enjoy a bit of V8 roar!
lockup and stall are different things.
The 1800rpm "slipping the clutch" feeling is the TC sitting against its stall speed. However the stall speed varies a bit depending on torque input and thus throttle position. Higher torque, means a higher stall speed, simply due to the fluid mechanics inside the converter. The throttle position also determines wether the trans holds onto the gear your in, and thus lets the engine rev up beyond the stall, or upshifts.
If your below the stall speed, and apply some throttle, the engine will tend to rev up to the stall speed and sit there. This effect boosts torque output, as a) the engines spinning faster and thus able to produce more torque anyway, and b) the slip in the converter gets used to amplify the torque further. Once speed in gear matches the stall speed, the engine revs will start to rise like a manual box. At light throttle, the box will shift before or just as that happens i suspect, and thus you'll find the revs just sort of sit around 1800 while it accellerates thru the gears.
The 4.0 and 4.6's also have (i believe) different converters with different stall speeds. From memory, the 4.0 stalls higher, to extract more performance from the engine. The larger 4.6 engine stalls out sooner, making it more refined. The diesels are probably different again to due the differing power band. Given these are old cars, its possible ones had the transmission changed and a different TC fitted?
The lockup clutch usually only kicks in in higher gears, and completely locks the converter solid, like a clutch on a manual car. This improves fuel efficency by removing the losses in the TC's hydraulic coupling. Newer boxes (like the modern 7/8 speed jobs) i think can use the lockup cluch more often, but the older ones like the P38's tended to only lock up in top gear at a certain speed.
Thanks.
I've got 10mm hose from the evaporator to the filter already. Its an 11mm filter, and i've got 11mm hose from there to the rails. I guess the 11mm hose will stretch onto the 12mm barb just fine, so i'll get the 12mm rails and T piece thing.
The LPGShop Valtek rails appear to have 5mm hose outlets, i'll email them and see if they can swap them for 4mm, but again i suspect the 4mm hose will squeeze on.
Will report back once the stuff arrives!
Cheers
I've replaced all the pipework already, did when i had the manifold off as some of the hoses looked a bit worn out. :)