wanted. air/fuel mix tip's

**GA61XX** · 28-01-2009, 05:20 PM

after a 5M-E engine rebuild, i'm now having prob's with the air/fuel mix..
the motor now "pings" under load.... i'm using 98 octane fuel...
is there any one who can help advise me on how to increase the fuel to air mix...
as i feel that the motor is running lean....

cheers

**thechuckster** · 28-01-2009, 08:23 PM

ignition timing right? too much advance will make it ping

vacuum reference line for fuel pressure regulator connected?

TPS positioned correctly (it should fuel cut on decel if in right spot)

there is no way to alter the fuel mix other than the fuck with the AFM

**GA61XX** · 28-01-2009, 11:28 PM

Originally Posted by thechuckster

ignition timing right? too much advance will make it ping

vacuum reference line for fuel pressure regulator connected?

TPS positioned correctly (it should fuel cut on decel if in right spot)

there is no way to alter the fuel mix other than the fuck with the AFM

ignition timing is already 2deg' retarded. not pinging as much. but may need more.

as for vacuum hoses i only have 4..

& yes the fuel pressure is one that is conected.

well i may need to adjust the AFM...

cheers & thanks for help

**oldcorollas** · 29-01-2009, 12:38 AM

2deg retarded with the ECU pins bridged?

oilgetting past rings cna make it ping also.
get thee to a place with a wideband sniffer?
or at worst, check the voltage of your narrowband?

**thechuckster** · 29-01-2009, 12:50 AM

5ME has no diag port - it has a vacuum thing on the dizzi for advance.

it also has no O2 sensor ...

GA61XX: check that you haven't got the dizzi in the wrong spot. Also - when you set the timing, did you disconnect the vacuum lines to the dizzi and block the hose ends? You have to block the hoses otherwise the motor gets more air than the AFM is measuring.

**oldcorollas** · 29-01-2009, 01:25 AM

oh........

thanks

**GA61XX** · 29-01-2009, 01:29 AM

Originally Posted by oldcorollas

2deg retarded with the ECU pins bridged?

oilgetting past rings cna make it ping also.
get thee to a place with a wideband sniffer?
or at worst, check the voltage of your narrowband?

This is a fresh rebuild.. 040" over size, with high comp' pistons..
head has been shaved 060"
comperssion is around 9.4:1
AFM is a recon' & has been tested....

Q:- what ECU pins need bridging

**oldcorollas** · 29-01-2009, 01:39 AM

sorry i got it wrong, i though tthe ECU controlled advance.. not the old system which was independent of ECU.
listen to Chuckster

hm, cam timing changed after shave? dizzy runs off cam? etc
perhaps wth the higher comp, it needs a bit less mech advance (or just turn dizzy back a bit)

**GA61XX** · 29-01-2009, 01:48 AM

"cam timing changed after shave? dizzy runs off cam?"

ok.. head shave 060" = about 2deg' retard..

dizzy runs of a seperate shaft..

at 1st i had the cam advanced about 2deg' & had very bad ping & knock...
only has a ping under load now with cam retard 2deg' aprox'

so i'm thinking another 1 to 2deg' more retard is needed...