testing toyota diagnostic circuit

Dain Bramage · Mar 3, 2008

i was wondering if there is any way to test the diagnostic connector on my truck (86 toyota pickup 22re). i think there is a problem somewhere in the circuit because when i jump the connector to try and set the timing, the timing mark doesnt change position. currently i have it set at about 30* BTDC. i tried setting the timing to spec (5*) with the connector jumped, but it had absolutely no power. this is really bugging me, because if there isnt an issue with the diagnostic connector/circuit, then that means my timing chain is off a tooth, which would really piss me off, because i only have about 32k miles on this engine, which is a reman'd long block that i got from jasper.:rant:

CHOP SHOP · Mar 3, 2008

advance it till it starts hard then back it off just enough to start smoothly. when it gets hotter this summer, back it off till it stops pinging.

Dain Bramage · Mar 3, 2008

i wasnt asking how to set the timing, i need to know if there is a way to test the diag circuit so i can set my timing properly and pull codes, should i ever have the need.

skrause · Mar 3, 2008

Short the connector, turn ignition to run position but don't start it, and check the check engine light. If it's working and there are no codes stored it should flash code 1.

Dain Bramage · Mar 4, 2008

alright, i tested everything, the wires are good, decided to pull codes while i was at it, and came up with a code 11. mitchell lists that as "a/c switch or neutral/start switch signal" being the affected circuit. probable cause is listed as a/c switch or TPS. but when i scroll down to try and figure out how to test it, for a code 11 it tells me to check the main relay and circuit at the ECU. it gives test procedures on the TPS for code 7. anyone have any experience with this?

skrause · Mar 4, 2008

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

Symptoms of a bad or mis-adjusted TPS include:

Inability to correctly set base ignition timing
i.e. you jumper the timing check connector and the idle and timing don't change

:awesomework: