FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: FC5959 on August 29, 2002, 08:27:34 AM



Title: Tuning problem
Post by: FC5959 on August 29, 2002, 08:27:34 AM
Help!!  ???

I had to replace the side plate gasket on my grey motor, this also involved removing the distributer. When the dizzy was replaced I tuned the car "by ear" however I soon found that it would not start once the engine was hot, so I checked the workshop manual and tuned the motor by the book - Timing ball on ring gear aligned with indicator mark, using a timing light (Points set to 0.015).

The car sounds great and revs well when it is stationary, however it loses total power when under load.

I have replaced the points then the coil and finally put in another dizzy all to no avail. Leads are near new as are the plugs - wiring looks OK - can't see any sparks coming off leads.

Is there a possibility that the fly wheel can be misaligned with the index mark?

Or could the carby have broken down??

Can anyone help  ???

Regards
Andy


Title: Re: Tuning problem
Post by: mcl1959 on August 29, 2002, 09:08:27 AM
There are 2 spots you can put the dissy in with the timing ball marks lined up on the flywheel.
You need to make sure that the inlet and exhaust valves are rocking on no 1 piston - then put the dissy in.  The easiest way to do this is by taking the rocker cover off.

Ken


Title: Re: Tuning problem
Post by: FC5959 on August 29, 2002, 09:20:38 AM
Thanks for the info Ken, however if the dizzy was aligned to 2 deg before TDC on the exhaust stroke would it not sound VERY sick if it started?
Andy


Title: Re: Tuning problem
Post by: HARKO on August 29, 2002, 10:21:04 AM
It would sound sick and you would'nt get the movement you need to adjust the dist ,I'd try looking at vacume to the distributor andor maybe your vac hose is sucking closed on a crease or something similar and if you have played with the carby maybe youre getting vacume in there but you said it runs fine in the driveway so maybe rule this one out (you would have a lumpy idle)
My money is on the vaccume line to the dizzy crimping up under pressure.
Le us know how you go !


Title: Re: Tuning problem
Post by: ChrisB on August 29, 2002, 11:07:27 AM
Hi FC5959,

Better listen to Ken !!!  I had the cam out and ground when I replaced my timing gear set, (" yes I bed the cam in ") when I put the dizzy back in I thought I knew how to put a dizzy in !!! sure car ran good, timed up on the ball with correct settings, tried another dizzy too. Car got hot ran o/k trouble starting hot. Decided to check all timing settings even pulled the timing cover back off to check marks on the timing gears. It turned out I had managed to put the dizzy in wrong. One tooth out.  When all else fails go to the trusty GMH book. I fitted the dizzy exactly as per the book and it was amazing the difference.

Good Luck ChrisB   8) 8)


Title: Re: Tuning problem
Post by: andy on August 29, 2002, 08:58:10 PM
Thanks Harco & CrisB

Harco
Vacume can not be a problem - steel line from carby to dizzy - and no, I did not touch the carby.

CrisB
I will try your suggestion and reinstall the dizzy EXACTLY as per book, (as this has worked for your hot starting problem).

I can see how valve timing can be out if teeth are misaligned, however if the dizzy is out by one tooth can this not be compensated for by rotation of the dizzy when tuning, ie. you are moving the body in relation to the dizzy cap hence obtaining correct firing. ???
Andy


Title: Re: Tuning problem
Post by: FCwagon on August 30, 2002, 02:48:51 AM
Hi Andy,
I've had similar problems over the years with motors that have been tampered with and at times have had to resort to making my own timing mark on the flywheel. Assuming your cam timing is right, you set you engine on TDC (#6 valves rocking) using a long thin blade screwdriver or drinking straw etc in the spark plug hole & sitting on the top of the piston. Rock the crank back & forth with the fan until you can guage where the mid point is - ie TDC. Make a mark on the flywheel with chalk or paint if the ball aint there. Set your dizzy rotor at or as close to the No 1 mark on the body, then with a test light connected to the points terminal, switch on ignition & move distributor until test light comes on. That should be TDC - worry about the other 2 degrees later. Tighten it there and go for a drive to check your power.
cheers,
Leigh