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[toyotaspeed90]

it wouldn't get 'stuck'

the ecu doesn't really have a set limiter in it. the rpm limit is based off the time/speed of a crystal in the ecu. you can change your rpm based on crystals that are in the ecu. So the only way it could be 'stuck' is if like i said something else is wrong and the ecu is in some sort of 'limp home mode'

base timing.... you know, with a timing light on the belts pointed at the pointer? lol. Like i said, timing needs to be checked with the ecu jumpered at the diagnostics port. (which means there won't be any sort of advancement or retard adjustments of timing made by the ecu while it's jumpered).


hahahahahahaha, i wonder about this (just came to mind).

what distributor are you running? are you sure it belongs to the ecu/ignitor you have? just because it plugs in doesn't mean it's correct. there are at least 2 or 3 4age distributors. The top cog on the shaft either has 1 tooth or 4 teeth. You need to make sure that you have the correct distributor. If you have an early model ecu (pre 87) then you need to have a dizzy that has one tooth on the top cog. If you have 4 and an old ecu, then that could potentially be the problem.

this is how i thought of this (and an explanation of magneto pickups in a distributor).

the distributor rotates on a shaft, where there's (on a 4age) 2 cogs (or wheels) that are bolted to the shaft. They are directly driven (ie, they don't speed up or slow down based on the speed of the shaft). The electronics in the distributor (again, for a 4age.... the electronics in many other distributors are different as they might contain the coil and ignitor inside) merely 'read' the speed of the shaft. If you play with a distributor outside of an engine, you will feel that there is a little bit of tension on the shaft, and that it doesn't spin freely (ie, you couldn't spin it and let it spin on it's own for quite a while). This is because the electronics actually are small magnetics. As a tooth on the distributor passes by it, the electronic reads it as a pule, and sends out the signals of the 'location' (ie count, because the ignitor/ecu know that there are so many pulses per cog per revolution of the motor).

so.... you could potentially get the engine running with the wrong distributor, but could be getting an incorrect reading from what it expects.

also, if you removed the dizzy and are off one tooth, then potentially timing is off and it won't rev past a certain point because you are getting to a pre-ignition rpm, where spark is happening too late and the engine is doing it on it's own (then gets a spark from the ecu, possibly slowing down the piston speed a bit).

lastly, try just unplugging your TPS for a short run. The ecu gets a reading from the TPS that it is either in a 1-100% open throttle. When it's at 0% throttle then it goes into and idle mode (most manufactures don't have this, actually). If your TPS is wrong (or, somehow one from an mr2 since those read backwards) you could be freaking the ecu out and it doesn't send the right amount of required fuel (and you should be careful if this is the case.... too lean can cause the motor to blow).