I have a 91 Camry with the 2VZE and 2 wheel drive 5 speed that once the motor gets to operating temp it has a real rough idle and stalls unless I am on the gas just enough to keep her RPM up. I pulled the codes and it says no RPM signal to G or NE circuit. In the Chilton book I have it tells me to measure the air gap in the distributor but I have no idea what that means or even how to do it.

Also the same code says it can be the ECU and I was wondering if anyone has an idea on the reliability of the ECU's in these cars because I also have a knock sensor code and the book says the ECU also or a loose wire.

If it is my ECU I know on newer cars when you get a computer you have to take it to a dealership so they can flash it but do I need to get this flashed or can I pull from junkyard and plug in then be done?

 

from personal experience
if the ecu or dissy module was faulty - they either work or not

2VZE my research says thats a V6 used in the australian lexus -and a few other camrys- no coil packs on this one ?
TOYOTA 88-91 Camry V6 LEXUS ES250 2.5L DOHC 2VZE unleaded


problem so far
when hot - poor /rough idle stalls ..no power

how old are the plugs and leads
any air gap fault ---to me means a worn distributor - maybe the bearing or housing

I cant find a dissy air gap spec for this engine and its dissy today ---- it has to be accurate

knock sensor would come into play if the idle is rough and stalls

ecu relaibility is good

yes you can pull one from a junkyard -from a similar model- same numbers on the outer casing of the ECU is even better

if we cant sort this....can we double check the fault code numbers please

air gap check for the 4 cyl dissy - not sure yours is the same spec for the air gap
Distributor
7. INSPECT AIR GAP
Using a thickness gauge, measure the air gap between
the signal rotor and pickup coil projection.
Air gap:
0.2–0.4 mm (0.008–0.018 in.)
If the air gap is not as specified, replace the distributor
housing assembly.

2. INSPECT SIGNAL GENERATOR (PICKUP COIL)
RESISTANCE
Using an ohmmeter, measure the resistance between the
terminals.
G pickup coil resistance (G – G[–]): 140 – 180
N E pickup coil resistance (NE – G[–] ): 140 –180
If the resistance is not as specified, replace the distributor
housing assembly.

side note
lots of pistons for sale for this engine ..hummm