I'm fixing up a 1991 240 LH 2.4 automatic. DTC for ECU is showing 2-1-3, TPS full load setting faulty. Planning on giving the wire contacts a good clean later this week but am preparing for possibly having to replace the TPS. I'm unlucky enough to have the rarer of the two TPSs used for this model (Bosch 0 280 120 325). Only source for a replacement that I've found is IPD where it's going for $350. Is it possible/advisable to use another TPS model? I've found some generic TPSs on ebay for much cheaper. Is it just a question of properly calibrating it or is there something unique about this Bosch TPS?

Thanks

 

Do you have the clicking kind of switch or the variable resistor one? Do you have any drivability problems? (If no why do you want to replace it? )What have you done so far? - - Cleaned throttle housing/plate, adjusted switch to click on and off when throttle is first opened (if that style)

 

As in the idle switch? It's a clicking one as far as I can tell. And re drivability the only issue I'm having is rough idle/stalling but only on cold starts. Cleaned the IAC valve and throttle body, issue persists. Idle switch clicks with the slightest pull on the throttle cable. If it's not a TPS issue my next guess would be a failing intank pump but it was just replaced a couple months ago and otherwise does seem to be running.

 

Did you set the basic idle by blocking off the iac air flow and setting the idle speed to ~750-800 rpm with the set screw then reseting the switch to click? Iac hose can be easily clamped shut - but maybe not so much with this much age, will probably crack!

Older 240s did not have a iac - they simply relied on the air flow past the throttle plate (plus an extra air bleed screw) to set idle speed. An air valve or later an iac would give more air when cold or as needed (load on engine such as alternator, ps, or ac.) In other words you can always adjust around an air valve or iac that's not working correctly - and yes you may have a high idle when hot with that process but that process is free!

Don't guess - if you think there's a problem with your fuel pressure - measure it.

For a rough idle use carb cleaner to spray the intake gasket and other areas to find any air leaks. A common manifold gasket break is near the #1 intake runner.