Mine was doing it last month, never did it last Summer, I rebuilt the carbs recently as the needle valves were sticking, I upped the mains, but I can't see that causing it? Waiting for rubbish weather to clear so I can finish the rear brake service and try another drive to see if it's gone away. Oh and test my CV boot rebuild at the same time.
The weather forecast is only getting worse so I've finished, test driven, popping all gone. It's not quiet, but doesn't sound like an exhaust leak. I still think there's an engine problem though, it's not the smooth running thing it was.
^ I did nothing else, no carb adjusting or heat exchanger torquing, just off with the new and old with the old. I tried my hardest to make it pop and couldn't.
Not enough back pressure?.. thought the stock exchangers throttled it?.. I'll look forward to having to sort the same issue when I finish messing with wires.. Sent from my SM-G930F using Tapatalk
I think it's illuminating a problem rather than causing it personally., I don't hear everyone's shiny exhausts popping. I haven't tried mains, but I tried reducing the idles from 57 to 52 and that didn't help. Past AFR tuning I know it's pig rich even with 52 but that's driving afr. Perhaps I should have tried tuning the idle mix leaner?
I am not sure how mains would effect it, perhaps they would? Idle jets seem more likely culprits in my head. Have to wait for the rain to stop.
I have AFR, I intended to use it with my new (my 3rd) sensor but I don't want to fit it while it's popping. Catch 22.
Could be. From what I could gather the stock silencer is perfect for 1700, getting restrictive for 2000 so should be the restriction for the 2400. The VS, unless I was deluding myself, worked better with one's foot down.
Having had some time to ponder an attempt to record the farting and popping that was foiled by wind noise... I went up through through 2nd and 3rd up a canal bridge incline, to about 3500rpm then let off down the other side down towards a slow corner. It didn't pop haha so I accelerated and tried again this time slowing right down and the slower it got the more it popped, but for the first 5 seconds no popping at all. Driving in town always ponderously, low speed low revs, it pops straight away if I take my foot off. There's a clue there somewhere.
If I zoom in on the head barrel, I see smudges that shouldn't be there? Gah! I was nearly at head off here a while back, I should have followed through instead of just re-torquing.
Find an old awning and stick it on the back of the bus so you can work under it. Or a really big polytarp and some ropes attached to stakes to make a tent over the back of the bus. I have taken engines apart in a polytarp tunnel between a wall and the back of my bus, fixed some eyes in the wall to attach the polytarp. It all got nasty when I spilled oil, walked in from the rain..and skidded.
I can't do any of that Mike, in the past letting people work on cars here resulted in a grave yard of abandoned wrecks. They made a rule and gradually cleared up. I only get away with what I do because the manager owned and worked on Beetles when he was younger, they know it's my only vehicle, I keep putting it back together, I never spill anything and at the end of every day it looks like any other parked car. The car park is usually full, I can't spread out though I might be able to wind the awing out 2ft to keep the rain out of the back. If I took the engine out...well I'm not going to try that here as it would have to go straight into the cargo area. Obviously it's not snowing now... Can't do it there^ it's a single row. Best place is other side of the blue van in a double row. Here, but the other way round so the rear is downhill. What a faff. I'll make a start anyway. If one's leaking at the head they probably both are. I hope they fall off the cylinders without disturbing the barrels...fat chance. Do I have a ring compressor for 104? No. Maybe I'd manage with a 94. I don't want to be doing this but I know I can go into a kind of trance and keep going.
If only I knew! I appear to have tried everything exhaust related several times, re-torqued the heads... It's a cam/firing speed tick. I can't find it but I have a pic of the cam bolts somewhere and it can't be them hitting the pump, so...it must be cracked or warped heads, it's not mechanical as far as I can hear with a stick-o-scope.
