| Author | Message | ||
     David Beard (Daveb_in_rsa) New Member Username: Daveb_in_rsa Post Number: 1 Registered: 07-2003 |
I have just set the timing on my V8 using a timing light. The engine was running fine before but using lots of petrol. I found the timing set at about 12 degrees BTDC! Having set it to the 4 degrees BTDC recommended in the South African market, I have a little less power below 2000rpm and the same fuel consumption. Also the exhaust gas is hotter now than before, indicating that the timing is wrong? Is it possible that the pulley marks are wrong (the marker doesn't seem to be bent)? If so, how can I set the timing correctly? I didn't have any pinking/pre-ignition when the timing was at 12BTDC. Following the advice on this board, I also checked the VAC diaphragm. It was leaking so I got a replacement fitted for the equivalent of $14. Thanks Dave | ||
| Rob Davison (Nosivad_bor) Dweb Lounge Member Username: Nosivad_bor Post Number: 616 Registered: 02-2003 |
i am assuming you are not the original owner? if you live in high altitude or worn cam or previous owner fiddled with plug gap then you can possibly be running and advanced timing like you have . it is not that unusual. why did you check it? are you having other issues? -rob | ||
| David Beard (Daveb_in_rsa) New Member Username: Daveb_in_rsa Post Number: 3 Registered: 07-2003 |
Hi Rob, No, I'm not the original owner. I have had it for about 3 months. Currently on 140000 kms. The engine is running fine but fuel consumption is up to 23 litres/100km around town. I decided to go through everything to see if I could reduce it; and if I couldn't then I would have to accept it! As the owner of many old Triumphs, I reckoned the ignition system would be the first thing to check so I changed plugs, did the VAC diaphragm and checked the timing as a matter of course. I will also check for fuel leaks, fuel pressure and leaking injectors in due course. I am interested in your comments about the high altitude - we normally retard the igntion to compensate? We only have 93 octane fuel here, which is another problem. The possibility of a worn cam is a great worry, I have heard much about this. Is there an easy way to check the cam, without dismantling half the engine? When I removed the old spark plugs, the gap was just about correct according to the manual. Is there any way to set the timing without the benefit of the timing marks, or for optimum performance/fuel economy? BTW, I see you are in Pittsburgh - I was there in 1990, and it is still one of my favourite destinations worldwide! Thanks Dave | ||
| Jim H. (Victor_mature) Member Username: Victor_mature Post Number: 126 Registered: 02-2003 |
I'm not sure about newer vehicles but back in the old days I used to set timing according to maximum manifold vacuum. Hook a vacuum gauge to the intake (below the throttle plate) and adjust timing (with vac advance disonnected) back and forth until you get the highest reading on your gauge, stop there and tighten the distibutor down and hook your advance back up. Now it's timed to optimum performance with whatever condition your cam/lifters/plugs/etc are in. Again, this was way back before MAF sensors, O2 sensors, IAC, etc, so not sure how the 'smart' parts of the vehicle will react to this method but give it a try. Let us know if it works. | ||
| David Beard (Daveb_in_rsa) New Member Username: Daveb_in_rsa Post Number: 4 Registered: 07-2003 |
Thanks Jim, I will give that a try - probably this weekend - and let you know how it goes! Dave | ||
| Shaun Power (Shaunp) Member Username: Shaunp Post Number: 90 Registered: 05-2003 |
David 8.13 compression cars run fine on 93 octane fuel but should do 20l/100k or less if you don't flog them. My own car does about 17/100. You need to check it with an exhaust gas analizer to see if it is runing rich as it may need the the Airflow meter adjusted or could have dodgy temp sensor. You can check your timing mark easy,just take out a spark plug and find TDC and then check if the mark lines up. To check for a worn cam you need a degree wheel and a dial guage. Just make sure the cam still has it's correct lift useing the dial indicator on the end of the push rods and that the timing is close to what it should be useing the same method but referring to a degree wheel stuck to the front pully. | ||
| micky dee (Kincangokicker) New Member Username: Kincangokicker Post Number: 30 Registered: 06-2003 |
im guessing that at one time the front pully was removed. maybe for timming chain or oil seal or something. and i am also thinking that upon replacing the little woodruff key was not replaced. thus maybe your timming arks out of phase. i did this once on a series and no one could have ever timmed the engine with a light. |
