timing questions

[mirageshepard]

Happy holidays to everyone and happy late turkey day to ya's (reception is horrible where I live)

 

 

 

Ok down to business, my swap went well and the engine runs STRONG!!!!!! which amazed me. I removed ALL emissions stuff as well! I set the ignition timing by the label on the truck that the engine came out of which was a 84??? 720 2wd auto, that was set up to be z24s Carb... 3 degrees BTDC, but when it was swapped into my truck 1986.5 hardbody 2wd auto, I converted the engine over to z24I TBI which is what my truck came with originaly, so I set the timing @ 3 degrees BTDC. My label that gives the ignition info for BTDC on the hardbody is missing because hood was changed before I got it and no one thought about keeping that label with the hood that replaced it.

 

 

NOW that I got this engine running decent I've ran into a few problems that I might can fix or maybe not if its because I removed emissions stuff. Being that I don't have a tach I cant see what RPM's its running @ but it seems abit high. when trying to start the truck it hesitates like its low on battery power or I have huge amounts of compression. Would the timing be abit different for my ignition being its TBI and not CARB? what other way can I find out what the ignition timing is for my hardbody? why are there different degrees in timing for the same engines? Thanks!!!

[DISLEXICDIME]

my 720 was doing the slow delayed starter thing. turns out my battery had a reversed cell

 

try turning the timing up or down and see how it reacts

[ggzilla]

Would the timing be abit different for my ignition being its TBI and not CARB?

YES, it will be different. But not by much.

 

All Datsun engines run OK on 5 to 7 degrees advance. which is not enough to cause starter problems. Also it might run best at some other setting, but will run OK at 5-7.

 

3 degrees is relatively retarded. It is done for emission control probably.

 

EFI engines often have a pre-set timing, for which you need to disconnect (or connect) two special wires before you can set the distributor spark timing correctly.

[mirageshepard]

YES, it will be different. But not by much.

 

All Datsun engines run OK on 5 to 7 degrees advance. which is not enough to cause starter problems. Also it might run best at some other setting, but will run OK at 5-7.

 

3 degrees is relatively retarded. It is done for emission control probably.

 

EFI engines often have a pre-set timing, for which you need to disconnect (or connect) two special wires before you can set the distributor spark timing correctly.

 

 

 

 

Thanks for the info, which 2 wires are the special wires if my truck has these special wires? BTW I used a timing light IF anyone was curious as to how I set the timing.

[ggzilla]

Dunno. You should look in a manual for the year of 720 the TBI system came out of. The library will have a manual.

[mirageshepard]

Dunno. You should look in a manual for the year of 720 the TBI system came out of. The library will have a manual.

 

 

I have read my manual but it just keeps telling me to read that label under the hood which I do not have. My TBI in my hardbody came from factory in that hardbody. I'm going to scratch my head abit more and see what I can come up with. I guess I'm just looking for an exact number because I don't want to be "off" any at all but I guess times like these close is good enough lol.