the sheilds on mine are burnt on the passenger side and the driverside one is completely missing.
I think if the engines throwing unburnt fuel into the cat, the cat can get REALLY hot.
Nah the battery was really low by the end, and i didnt want to abuse it more than i already had. My chargers a bit puny and it had only been charging for a couple of hours from dead flat, so not really a huge amount in it. Leaving it on overnight to fully charge.
Will need to try it again with a shot of oil in the cylinder once the battery has some charge in it! Is it worthwhile doing the test on a hot engine?
So found my compression tester and some free time, went out to test it and found the battery completely flat. Doors wouldnt even unlock... Great.
Stuck it on the charger and instead tackled some other bits. Stripped the intake off and removed the injectors. Swapped in my spare Audi injectors and refitted the fuel rail. Also removed and inspected the ignition coil, and discovered that it looked somewhat melted. Almost like it had been on fire! rather odd! It seems to be working fine, but something i probably want to change at some point. Reinstalled the middle inlet manifold and figured the battery might have enough juice in it now as doing the injectors took feckin ages.
So got the compression tester on the go, i started at cylinder 8, as that was the oiliest and got these results:
8: 11 bar
6: 8.5 bar
4: 13 bar
2: 13 bar
1: 13 bar
3: 12 bar
5: 11.5 bar
7: 11.5 bar
The battery was getting a bit weak towards the end, so i suspect the last three cylinders would probably have managed closer to 13 had the battery been fully charged. However clearly something odd going on with 8 and 6, those two cylinders are the one that are fouling the plugs up with oilyming too.
Reassembled the inlet manifold, and gave it an oil change then managed to get the two lambdas swapped out for new ones. Not fired it up yet though.
aye fair enough, i'll have a close look at the LPG layout. Will take a pic of the injector points. Its been on there for over 10 years though. There was a note at the last LPG service saying one bank of injectors wasnt working properly and they'd need replaced "when the vehicle became undrivable" ffs.
I've been reading a bit about the TVR guys replacing their Lucas ERR722 injectors with some Bosch Gen2 200cc injectors from a Mustang, which are supposedly much better than the lucas ones. As it happens, i have 12 210cc Bosch Gen2 injectors in my shed from various Audi 1.8T engines i've stripped for parts. Think i'll give them a clean and swap them in, rule out dodgy injectors.
I will try to sort out a compression test. I think i have a tester somewhere!
This is been running on petrol so it shouldnt be a gas/injector issue.
I'm in Fife, Scotland.
ok, faught rediculous winds and pulled the spark plugs out just now. Certainly something odd going on!
https://www.dropbox.com/s/azls39kcog9xjx4/2016-09-27%2017.45.00.jpg?dl=0
These plugs were new, probably less than 10 miles ago. Albeit most of that distance done with what would seem to have been a fualty MAF sensor.
The odd bit, is they're all quite different.
Starting with bank1 they all look "okish" with the caveat that 5 and 7 both have soot covering exactly half of their plug ceramic.
Bank 2 is where it gets all weird. Cylinder 2, is the same as bank 1. Cylinder 3 is dark and sooty. Cylinder 5 is darker and sootier, plus also looks oily. Cylinder 7 is VERY sooty and oily with weird deposits on it (i presume burnt oil).
Thoughts? I'm thinking perhaps faulty injectors, and/or some sort of mechanical issue? The oil could simply be valve stem seals, or something worse.
Theres a note in the history from the last LPG service (5 years ago...) about a fault with one of the LPG injectors "fluttering", but seems it was passed over with an "ignore it until it gets worse" type comment.
When running on petrol the short term trims look sensible enough. Switch to LPG and one bank goes to -25% and the other bank to +25% and it just sits there... Certainly not happy! In my mind, if i know its running properly on petrol, and the readings etc can be trusted, then i know i can trust the info to sort out the LPG issues.
I've noticed that even on petrol the short term trims are perhaps acting oddly, at idle one bank shows mildly positive, and the other bank is slightly more negative. Not a huge amount though. say -5% and +3%. However if you raise the engine RPM's, it seems to get wider. at 3000rpm, the positive bank has increased to maybe +9% and the negative bank is at -11%ish.
I've ordered a pair of new lambdas for it. Also thinking about pulling the fuel injectors and having them cleaned. I'm also going to re-check the spark plugs condition, and pull the ignition coils out and ensure they've not "burst".
Getting pissed off with this bloody car now!
Took it in today for another emissions test having replaced the MAF sensor. Looking with Torque, the STFT's are within a normal range (they looked a bit wonky with the old MAF)
He said "its getting better" but couldnt give me a print out, as apparently the machine "choked" and couldnt complete the test. I asked what the numbers were, and all he could tell me was 0.35% CO, then the machine choked out and aborted the test. I asked what would cause it to choke, and he said usually missfiring or overfuelling. Hmmph. I've sat revving it on the drive way and cant detect any hint of overfuelling or missfiring. the exhaust smells clean and not rich etc etc.
Not sure what to do now? Do i stick some new lambdas in it? anybody got any ideas?
Oh, and i asked them to test it on LPG, and they refused saying LPG messes their machine up or some nonsense. Not sure that would help anyway as the STFT's on LPG are all over the shop, clearly the LPG system needs some TLC. Yes, i could go somewhere else, but clearly, the car should be able to pass a petrol emissions test, and the other MOT places in the area are worse than this place.
fair enough, thats good to know. Clearly i want to fix it "properly", but not being able to properly test drive it gets quite annoying and makes it difficult to figure out whats going on.
I think the cats are fine, as otherwise it wouldnt have managed the 0.16% CO at tickover. Typically a decatted car will run around 0.5%. Its usually impossible to get below the 0.3% cat limit without actually having a cat.
I'll get this MAF swapped out (ordered a genuine used one from ebay) and see what happens. If its still being a shit, i'll tell them to switch it onto gas and run the test on that just to get it thru while i figure out whats going on.
Hmm didnt know that about LPG? I've been running it on petrol because i'm not sure the LPG works properly, and common wisdom seems to be to get things working right on petrol before trying to get LPG working. It needs fixed either way, as it clearly should be perfectly capable of passing the test!
Can you find me a definitive source for those readings? I've looked in the MOT manual and it doesnt mention different limits for LPG systems, only reference it makes is that hydrocarbon limits on LPG need to be converted to account for propane vs hexane.
Orangebean, yeh i realise its a generic reader, but lambda on bank one cycles nicely between ~0.2 and 1v, the other bank is just stuck at 1v, but only while revving it at 2500rpm. Drop to idle and they both drop to 0.2v and the STFTs swing from -10 and -25 to +3-4ish and then start switching normally. So the readings make some sense.
I've realised since posting above that i've put it in for the bloody emissions test without the MAF connected. I mustve forgotten to connect it this morning :( However i plugged it in and it wouldnt run at all, so there would defo seem to be something up with the MAF.
Ok just took it for its MOT test again.
Failed on emissions. YEY!
1st Fast idle was 1.51% CO, but with 69ppm HC and lambda at 0.976 - FAIL on CO
2nd Fast Idle was 1.22% CO, but with 53ppm HC and lambda at 0.982 - FAIL on CO
Natural Idle Test was 0.16% - PASS.
So its running fine at idle, but getting rich with revs, which does suggest to me a MAF problem?
Looking at the STFT's on Torque, at idle the STFTs are both slightly positive, 5-6%, however at 2500rpm, bank one drops to -10% (with its lambda switching sensibly), and bank 2 drops to -25% (with its lambda stuck at 1v) So perhaps a bank 2 lambda issue?
Bank 2 lambda does switch normally at idle though...
yeh, the problem i have is that the pre-97 cars have a flat plate welded to the axle case, which the flexi bracket attaches to. My axle doesnt have that plate, so i'm assuming someones fitted a later axle at some point for whatever reason.
If i retain the early system, i need to fabricate a mounting platform on the axle case. If i switch to the later system i need to fabricate some mounting brackets on the chassis to accept the later pipes.
Just trying to figure out which method will be easier in terms of access etc.
Cleaned the MAF last night, not that doing that ever actually works but it was pretty grotty. This morning i refitted it, plugged it back in and started the engine. Fired right up and idled and revved completely happily. So whatevers going on is very clearly temperature related.
Coolant sensor checks out fine on the live data, as does intake air temp, so its gorra be something that doesnt like getting hot and is stopping working...
Sequential system with a Bigas ECU.
Went out just now as its been sat a while and decided to see if it would start. With MAF plugged in, it catches then immediately stalls. Tried a couple times, same thing. Unplugged the MAF again, this time it catched, revved a bit, almost died, revved a bit, almost died then shot up to 2500rpm and ran fine. Put the MAF back on, same thing as the first time, an initial catch then just dies. Unplugged it again, and again, it repeated the catch-rev-almost-stall-rev-almost-stall-running fine cycle that it did the first time. So Maybe it is the MAF? Or maybe the ECU's just getting confused with sensors appearing and disappearing?
I've taken the MAF off and cleaned it. Trying to diagnose this stuff with no MOT is particularly annoying as i cant really drive it around and see whats happening. At least today i had an excuse as i was driving to and from the MOT station etc.
First of all some background. When i bought the P38, it came off ebay, with one listed fault, a bad crank sensor. Apparently the engine would run for about 15mins, then die. The bloke told me the rear seal was leaking and that had contaminated the sensor. Sounded fishy but the cutting-out-when-warm i'd seen before with crank sensors, so i figured it probably just needed a new one.
When i got the truck home, i put a new crank sensor in it, but discovered the one i took out really wasnt all that old. Hmmmm!
So, take the P38 in for its MOT today, Drove it up and down the dual carridgeway probably 6 or 7 miles to make sure it was all running fine, then dropped it in for its test. Went back to collect it and the boy tells me he couldnt test it as it wouldnt run, kept cutting out. Great.
So i drove it home, just. Last half mile it was acting very strangely, missing and cutting out and not wanting to idle, before finally stopping right outside the house. I managed to coax it onto the drive, and sat there pondering what was going on. Tried ot start it a few times and it would start, rev up a bit then you could hear the engine had simply stopped firing. Adding more throttle would sometimes help it pickup but it would fart about for a few seconds then die.
First thing i did, somewhat randomly, was pop the petrol cap off, to be greeted with a loud and pronounced hiss. Hmm, vacuum in the tank perhaps? I started it, and it fired up perfectly and dropped to a nice idle, revved fine, ran fine, all seemed fine. OK i thaught, somethings wrong with the tank breather. But lets be sure, i'll take it for a drive and see if i can repeat the same fault.
Drove to the petrol station, no dramas, removed cap and there was a small hiss. Put a tenner in and drove home. About a quarter mile away this time, it just dies. I coast into a side road and try to restart, but nope it starts revs abit, pops farts and cuts out. OK i thaught if its a fuel delivery issue, i'll see if it'll switch over onto gas. Started it, revved it a bit and hit the gas button. Once gas came on it suddenly sounded much nicer, revved up nicely, but it was short lived, as a few moments later it starts missing on gas as well before stalling.
Scratching my head and wondering how i'm going to get it home, i sat about a bit, tried it a few times, then after some pondering, unplugged the MAF... It fired right up. Waited a moment to see if it was shortlived, but nope, kept ticking over. But hmm! its done exactly this before with the petrol cap.... So set off home and it drove home just fine. Much like the trip to the petrol station, it drove with no issues and all worked perfectly.
Back at the house i ran it on the drive for 10 minutes with no issues.
Sooo, whats going on? MAF failure? Fuel tank cap a red herring?
ahha that makes a bit more sense then, and explains why the part i found above only has one hole for the brake pipe and not a hole for the flexi. Its from the body end of that second flexi. I see now on the microcat drawing, that the lower chassis tab does not have a part number, though the upper one does.
If its not too much trouble, a pic of the routing of the second flexi and short hardline would be appreciated.
This is interesting:
screen grab taken from autodoc.co.uk, who list the caliper flexi hose and show it coming with the metal plate.
Ferryman, those pics are great! Could you possibly photo the axle end of that flexi hose, so i can see if whatever is supposed to be at that end exists on my axle?
also, the brackets that you've pictured, are they bolted to a tab thats attached to the chassis?
Interesting that your brackets have two holes, one for the pipe and one for the ABS sensor, whereas the part number i found only appears to have one hole. More searching required!
Sloth wrote:
Could always use some big chunky cable ties to hold the bracket in place on the axle, even if just temporarily. Not sure I'd want to drive around with that flapping about risking the solid lines fracturing.
I already fitted a jubilee clip around the axle tube and thru the hole in the bracket to secure it. Its much better now, not flapping around, but its still not in the correct place, and the hardlines have had n months/years of being getting waggled about so i dont trust them and thus it needs replaced anyway!
it looks like the chassis brackets for the jump hoses can be purchased from the dealer, and just bolt on...
Microcat suggests its this piece: http://www.brit-car.co.uk/product.php/107960/5497/bracket___brake_pipe
Hence hoping for some photos, if i can see where they attach and see if my chassis has provision for the mounting bolt etc!
Bolting on a couple brackets and making up some short brake lines (which need remade anyway given the mess of the ones on there) seems an easier solution than trying to weld a platform onto an axle full of gear oil...
While bleeding my rear brakes, i discovered the bracket that holds the rear brake pipes to the axle case just floating in thin air:
https://www.dropbox.com/s/hinsgnb8s5vdzsi/2016-09-17%2012.31.51.jpg?dl=0
I tried to see where it had come off, but couldnt figure it out. There was no witness marks or remains where it had broken off. I also noticed the metal shields that are covering the abs cables were only attached at one end, and were just floating at the other end with nothing to bolt onto.
I started wondering what on earth was going on, and today managed to get a photo of the rear axle on a '95 P38:
https://www.dropbox.com/s/82m9nx6ie4062y7/IMG_20160918_140308525.jpg?dl=0
Slightly different angle, but you can see the same hose bracket, and also can see that its bolted to a small "platform" thats part of the axle case. You can also see the wire covers are bolted to a tab on the axle. These features arent present on my axle.
Sooo, i suspect my axle has been swapped out for a later one, as later trucks didnt have the centre mounted flexis, and instead had a flexi at either end.
I want to fix it properly, leaving me two options. Fabricate a platform on the axle case to properly mount the bracket, or convert the pipework properly to the later spec.
Can anyone get me some pics of the later pipe layout? I believe theres some sort of bracket at each end of the axle, then a flexi upto the chassis to another bracket.
I need to have a look on my axle and see if the axle brackets are still present!
