350i distributor vacuum connector
Discussion
Right I've been checking all I can on the engine to track down the intermittent misfire. This evening I gave the dissy a good look over and found the vacuum advance section to be loose and rattling around so I've tightened that up. One think I noticed is that there appears to be a second vacuum connection on the back of the diaphragm as pictured. The main vacuum hose fits to the front of the unit. Any idea what this second one is for? Is it merely to allow the diaphragm to move freely, i.e. open to atmosphere or am I missing some plumbing?
Thanks.
Thanks.
Thanks for the reply gents - one less thing to worry about.
I've got some proper electrical terminal/contact spray coming tomorrow so I can give the resistor, AFM and ECU contacts a proper clean up. New coil arrived today but I'll see if cleaning the contacts does the trick before I swap anything else. I'm assuming that the very loose ignition amplifier and equally loose vacuum advance unit probably also won't have helped!
I've got some proper electrical terminal/contact spray coming tomorrow so I can give the resistor, AFM and ECU contacts a proper clean up. New coil arrived today but I'll see if cleaning the contacts does the trick before I swap anything else. I'm assuming that the very loose ignition amplifier and equally loose vacuum advance unit probably also won't have helped!
Right, definitely something very wrong with the distributor! No wonder the ignition amp and vacuum advance have shaken themselves loose! I'll try a new cap and rotor arm but I'm thinking a new dissy is probably the best way forward.
http://s148.photobucket.com/user/keith_knight1/med...
http://s148.photobucket.com/user/keith_knight1/med...
edbradderztvr said:
Keith,
Changed my distributor when it caused starting and running problems.
The centre shaft had alot of play if tugged up and down.
If you've got excessive movement, it probably is fecked so sadly time to replace. Think i bought a Powerspark one from flea, user name something like "Simonbbc", based in Bromsgrove. Very helpful on the phone. Cost about £90.
Hi Roger and Glen, new one ordered from the man at Bromsgrove - £103 including new high power coil. Away camping for a week from tomorrow, in the pouring rain, so will have to have a look at this when I'm back. Changed my distributor when it caused starting and running problems.
The centre shaft had alot of play if tugged up and down.
If you've got excessive movement, it probably is fecked so sadly time to replace. Think i bought a Powerspark one from flea, user name something like "Simonbbc", based in Bromsgrove. Very helpful on the phone. Cost about £90.
Just back from a weeks camping so Wedge is very much in the dog house and unloved due to its lack of reliability. Tomorrow it's bonnet off, all plugs out, TDC found, and whipping the old knackered dissy out. New one has been delivered to my office whilst we've been away so will get that on Monday and fit Monday or Tuesday evenings.
Right, I've pulled the old dissy out today - some play in the bearings side to side but not excessive however there's a good 1/4" vertical play. If I suck on the vacuum advance it advances and then sticks and does not return to original position, if I rotate the shaft there's a nasty clicking noise and the rotor arm is noticably distorted also which is interesting. It's actually the distorted rotor arm that's causing the dissy cap to kick about.
New dissy was delivered to my office Friday so I'll fit that hopefully tomorrow night, if taxi service for the kids allows.
New dissy was delivered to my office Friday so I'll fit that hopefully tomorrow night, if taxi service for the kids allows.
Right, new dissy fitted and car started first turn of the key. I timed it at 8 degrees BTDC but it pinked like mad so I've taken it back to 4 degrees for now. I only pottered very local due to lack of bonnet but all seemed good and the dissy wasn't doing the hokey cokey. I'll get the bonnet back on tomorrow evening and give it a longer run just to check all is well.
Only little niggle is that the new dissy has the ignition amp opposite the vacuum advance whereas the original had the vacuum advance at 12 oclock with the amp at 9 oclock so there was plenty of adjustment. Seems to work fine though. Fingers crossed for the longer run.
Only little niggle is that the new dissy has the ignition amp opposite the vacuum advance whereas the original had the vacuum advance at 12 oclock with the amp at 9 oclock so there was plenty of adjustment. Seems to work fine though. Fingers crossed for the longer run.
Got the bonnet back on and been annoying the village driving about. Engine still pinked badly at 4 degrees BTDC when hoofed and also at 2 degrees so now set at TDC according to markings, which to be honest was where it was previously. Car runs clean, pulls strong and no evidence of any misfire.
One thing I do notice is that the engine doesn't like having the old timing light connected to no 1 HT lead. It's an old fashioned lamp which connects in line from spark plug to HT lead. When connected the engine over a minute or so started running rough and eventually died. As soon as the timing light was removed then all was back to normal. Does the ECU sense No 1 plug firing so and fitting the inline lamp affect things? I'll have a few days taking the wedge to work to ensure all is well. Cheers for all advice.
One thing I do notice is that the engine doesn't like having the old timing light connected to no 1 HT lead. It's an old fashioned lamp which connects in line from spark plug to HT lead. When connected the engine over a minute or so started running rough and eventually died. As soon as the timing light was removed then all was back to normal. Does the ECU sense No 1 plug firing so and fitting the inline lamp affect things? I'll have a few days taking the wedge to work to ensure all is well. Cheers for all advice.
Took the wedge to the office today and no misfire however it's still pinking at high revs/high load with timing now set at TDC. If I try to creep it back on the timing then it pinks at all bloody revs. The dissy is a new one from Powerspark and is supposed to be for landrovers and 350i, according to the list of compatible cars. I've read that different dissys have different counterweights and vacuum advance curves. Could it be that the new dissy advance curve is a little too severe/different to the original?
Looking at my old dissy I'll be honest and say that the vacuum advance is so knackered I doubt it's been working for some time. I presume I could try a drive around the block with the vacuum hose disconnected and plugged to see how that behaves? Any thoughts?
Looking at my old dissy I'll be honest and say that the vacuum advance is so knackered I doubt it's been working for some time. I presume I could try a drive around the block with the vacuum hose disconnected and plugged to see how that behaves? Any thoughts?
Thanks gents, I can get my hands on an original Lucas dissy next week for a Rover V8 so might pop that in to see if there's a difference. I'll also top up with some 97 Ron, which I had been using of late but the last couple of tanks were basic Morrison stuff.
The original problem was a very noticeable misfire which felt as if the car was going to die - that's now all gone and if I drive is reasonably sensibly it all goes fine - it's only at the top of the rev range when booted hard that it pinks. If I let the revs build up to max without full throttle boot then all is good. I will also investigate the costs of rebuilding the original. Cheers.
The original problem was a very noticeable misfire which felt as if the car was going to die - that's now all gone and if I drive is reasonably sensibly it all goes fine - it's only at the top of the rev range when booted hard that it pinks. If I let the revs build up to max without full throttle boot then all is good. I will also investigate the costs of rebuilding the original. Cheers.
Hi, I'm timing off the crankshaft pulley wheel. Something not quite right with this new dissy. I'm going to get a new timing light also as when I plug the old unit in, which has the sensor connected in line between the spark plug and HT lead, the engine runs rough and not happy. As soon as I disconnect all is happy again. It's my birthday next week so I've dropped enough hints and left enough suitable favourites in the Amazon basket and ebay "watchings" that hopefully she'll get the hint!! I'm also getting my hands on another dissy on Monday to give that a go. It runs sweet up to around 4700rpm and then starts pinking.
mrzigazaga said:
Apparently the new distributors are nothing like the cough cough "Modified TVR distributors"...They are okay for Rover applications but foul on the top rad hose on a Wedge...Making adjustment very difficult...I might need to replace mine but I'm waiting for a friend to test something he has in mind and if works then its something we might all consider...
Keep your old dizzy......
I stripped my old "hokey cokey" dissy tonight and to be honest it's not too bad. The biggest issue is the totally warped rotor arm which has twisted a good 5mm out of true, no doubt not helped by the enthusiastic speed and corresponding under bonnet temperatures at Millbrook. The vertical movement on the shaft is down to a badly shrunken and perished O ring that sits under the circlip but above the 8 point magnetic pick up. I'm now intending to give it all a damn good clean, light oil and try a rebuild myself as there's not a lot to the dissy when you take it all apart. The vacuum/advance unit now works all fine since I've stripped, cleaned and lightly oiled it.Keep your old dizzy......Same Powerspark dissy and undrivable with pinking unless set at TDC. I did have a 2 hour drive up and down to Loton park yesterday to see the TVR-CC Sprint meeting - filled up with super unleaded 97 Ron which improved things but still pinks at high revs and full load, which it didn't do previously. It somehow takes the shine off driving it.
I have stripped and rebuilt the old dissy over the weekend and managed to find suitably sized seals and o rings, plus fitted new amp so that's going back in one night this week to see how it behaves.
I have stripped and rebuilt the old dissy over the weekend and managed to find suitably sized seals and o rings, plus fitted new amp so that's going back in one night this week to see how it behaves.
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