mighty boy wont start need help
F8B EFI turbo - Three pots and a snail.
ok thanks mate
me217
1985 suzuki mighty boy : mods, f8b
1990 toyota mr2 gt import : mods, turbo timer, short shifter, 2.5" exhaust
1992 suzuki sierra : mods, g16b mpfi, 235's/75, snorkel & lift on the way.
1985 suzuki mighty boy : mods, f8b
1990 toyota mr2 gt import : mods, turbo timer, short shifter, 2.5" exhaust
1992 suzuki sierra : mods, g16b mpfi, 235's/75, snorkel & lift on the way.
We haven't asked if a "wet" compression test has been done after the initial test, which i would guess was a dry test? I was taught you follow a dry comp test with a wet test if you find comp is lower than expected.......Brayden wrote:If you're getting 120 across all cylinder then I'd be doing a leakdown test to see if the cause of the problem is worn rings or because the valves aren't sealing properly - which would indicate a cam timing issue.
It is unusual for worn rings to give consistently low results across all cylinders.
My F8b picked up almost 20psi on pot 2 with some oil in the bore - indicating worn rings. If it didn't pick up anything, it would indicate valve issues. Pulling the engine down & measuring the rings & bores found the bore warn as well as the rings......
Cheers
ToranaGuy
It's update time MB Parts list! send part info to toranaguy74@optusnet.com.au|
Compression test twice over. 1st time as normal, second time a squirt of oil down the plug hole. A significant change in figures means rings/bore wear.
Close numbers indicate valves/head/gasket but you have to look at all symptoms together to make your diagnosis. e.g. a cracked head or blown gasket will normally allow oil & water to mix & can show differing compression across the cyls. So you will will most likely narrow things down to rings or valves.
Close numbers indicate valves/head/gasket but you have to look at all symptoms together to make your diagnosis. e.g. a cracked head or blown gasket will normally allow oil & water to mix & can show differing compression across the cyls. So you will will most likely narrow things down to rings or valves.
So many delays to getting my MB back in order with 993cc & 5 speed transaxle... neighbor issue gone, donor shell up on rotisserie, new sheds on the way.... another project also..
Wet/dry compression tests are pretty stone-age. Leakdown testing is quicker, easier and more accurate!
F8B EFI turbo - Three pots and a snail.
have you tried replacing the condensor that is located underneath the dizzy.
On the add occassion, it will attempt to fire up and die immediately.
It sounds like thats fried.
Replace your points and condensor and give that a go!
As long as its got the borderline of compression, and other bits are correct, it will start up
On the add occassion, it will attempt to fire up and die immediately.
It sounds like thats fried.
Replace your points and condensor and give that a go!
As long as its got the borderline of compression, and other bits are correct, it will start up
It sure is more accurate, but if you don't have the gear or have access to gear to do a leak down test, the dry & then wet comp test will give you an idea if you should rebuild the bottom end or not.Brayden wrote:Wet/dry compression tests are pretty stone-age. Leakdown testing is quicker, easier and more accurate!
Cheers
ToranaGuy
It's update time MB Parts list! send part info to toranaguy74@optusnet.com.au|
i put in new points and condenser but i think the condenser may be faulty cause it worked for awhile.
me217
1985 suzuki mighty boy : mods, f8b
1990 toyota mr2 gt import : mods, turbo timer, short shifter, 2.5" exhaust
1992 suzuki sierra : mods, g16b mpfi, 235's/75, snorkel & lift on the way.
1985 suzuki mighty boy : mods, f8b
1990 toyota mr2 gt import : mods, turbo timer, short shifter, 2.5" exhaust
1992 suzuki sierra : mods, g16b mpfi, 235's/75, snorkel & lift on the way.
What about wiring to the coil - is it ok?me217 wrote:i put in new points and condenser but i think the condenser may be faulty cause it worked for awhile.
Cheers
ToranaGuy
It's update time MB Parts list! send part info to toranaguy74@optusnet.com.au|
Your confusing the comp ratio with the comp pressure. 120psi is around the bottom of the service limit of compression pressure.EVL_801 wrote:ok but these guys were saying 120 was low befor lol im confused
Please have a look at this link, it's the F5a service manual.
http://www.icbm.com.au/mightyboy/images ... Book/9.jpg
I've just re-read it, and the comp at best should be 192psi, and the service limit is documented at 140psi. Right at the top of the page! Your engine with 120 psi compression is actually below the service limit. Maybe i'm thinking 120psi is the F8b limit or maybe i'm wrong & it would also be below the service limit in a F8b as well.
Cheers
ToranaGuy
It's update time MB Parts list! send part info to toranaguy74@optusnet.com.au|