Thread: Fuel & Tuning 2.25l

blue smoke is usually oil burning. If its running ok have him check the crank case venitilation setup. That doesnt discount a bad valve stem seal but you wouldnt expect that if the guides were done.

If its had the valveseats replaced normal unleaded is fine if it hasnt then running a valve saver additive is generally a good idea and in a pinch a small amount of diesel will do the trick (bout 100ml to a tankfull but you'll need to experiment) in a pinch.

its a series 2.25 what power? In seriousness the timing could be a little retarded and the mix too rich.

1. Unless doing continuous freeway driving, standard unleaded is suitable. Just check for exhaust valve clearance regularly, and fit hardened valve seats when necessary.

2. Lack of power without missing is most likely to be ignition timing. This may be either static timing or problems with the vacuum advance. A compression check would rule out other problems, and tappet clearance should be checked. Also check throttle linkage adjustment.

3. Blue smoke, if most apparent after idling, will be valve stem seals. There are two other possibilities. One is glazed cylinder walls, which would also also explain the power loss (compression check may solve that) the other is a fault with the antipollution gear. Exactly what is fitted will depend on the model, but if the crankcase vent valve is stuck, it may be sucking oil fumes into the intake manifold, giving the smoke, and extra air may weaken the mixture causing lack of power.

Note that there may be more than one problem.

John

Thanks for the prompt response and suggestions Dave, I'll pass your advice onto the owner (I've suggested that he register on AULRO) and probably knock on his door again after I return from a spot of trout fishing today.

Timing is currently set to 9deg BTDC - no pinking when under load in 3rd gear on hill - would you suggest advancing further?
Idle mixture adjustment could be leaned off a little but I'm unaware of any other adjustment to lean off the mixture.

Thanks John for your valued advice and suggestions (you must have been responding as I was answering Dave) - especially point 3 which could very well be 'on the money'.

I'm sure the owner will appreciate the advice and will be amazed at the speed of the responses.

Thanks again.

9º BTDC might be a bit far, 'the book' says for 90-96 octane fuel use 6º BTDC.

Originally Posted by isuzutoo-eh

9º BTDC might be a bit far, 'the book' says for 90-96 octane fuel use 6º BTDC.

Forget about what the book says. On these engines, timing lights and settings are nearly a waste of time, apart from giving you a place to start. With all the wear points it is best to do it by ear.

Loosesn the dizzy, and With the engine running, slowly advance the timing listening to the motor. It will increase in revs, then it will start to slow/run rough. Retard back to just before peak revs, and that is your timing set for that motor. Then check your vacuum advance is working.

CC

Another possible cause for the power loss not mentioned - stuck centrifugal advance, or badly worn distributor.

John

6 degrees is also the static set point and as CC pointed out is only a starting guide.