1998 Tacoma ECU Replacement

I have a 1998 Toyota Tacoma SR5 4x4 M/T and have an issue with the motor shutting down. Sometimes it's while I'm running down the HWY and other times will not start back after driving for awhile. But if you spry starting fluid into the Throttle body it will start and you can drive it again. I think I'm having issue with the ECU and looking for replacement Part number is 86691-04410. Does anyone know if any other ECU's will work, It is 3.4 V6 with manual transmission. Thought I was having fuel pump problems at first and replaced the pump and started doing same again so I replaced the pump again and still having the same problem. Thanks

 

Does it sputter at all or just die immediately? And if it dies instantly please stay off the highway! Your putting lives at risk.

I'm not completely convinced this is an ecu issue however if you decide to replace definitely stick to the stock ecu

 

Have you checked to see if you're getting proper fuel pressure past the filter? Might be as simple as a clogged fuel filter (if you haven't changed it out yet). They're cheap and easy to replace on the v6 Tacomas

 

Two fuel pumps and nothing changed tells me its probably not the fuel pump.

ECUs are typically extremely reliable- why do you think it is that?


I would be more suspicious of an ignition coil or a sensor or something.

 

Thinking it’s the ECU because I’ve swapped the pump twice and changed the fuel filter also, there is a problem somewhere in the start sequence because you can’t hear the pump kick on when the switch is turned on but yet when you spray the starting fluid in and it starts then the pump supplies fuel. If it was a cam or crank sensor then there wouldn’t be spark, if I’m correct???

 

Welcome to TacomaWorld
Spark and fuel pump only happens when ignition is in crank position

 

Just ordered Crankshaft position sensor and Camshaft position sensor once they come in and I get them installed we will see where I’m at. ??????

 

Throwing parts at the truck is not a good troubleshooting method. I would check the OBDII reader for codes. That may point you in the right direction.

I agree with Saucy and OxDEADBEEF, probably not the ECU. Do some research, and find out what components work each system. Then you can isolate and eliminate, or troubleshoot.

 

No Check Engine Light and No Codes Showing, ECU get signal from Start and NE (Crank Position Sensor) for Spark and Injectors. So going to replace Crank Sensor, but figured while I had the cover off I'd replace the Cam Position Sensor also.

 

Did you end up fixing it?

 

Replaced both and would not start at all. Pulled the crankshaft sensor at it was cracked so I put the old one back in and it started up. But started acting up but with new symptom of throttle issues. So I have ordered a new mass airflow sensor and reordered a replacement crankshaft sensor.

 

OEM mass airflow sensor? The aftermarket ones usually cause problems of their own, these trucks don't mix well with aftermarket sensors.

 

Yes Delphi mass airflow sensor.

 

Might get lucky it might do the trick, but there are a lot of accounts on here of aftermarket sensors - particularly the MAF - causing problems. Just something to keep in mind in case the issue persists or a different one comes up

 

Ok, thanks for the information should know something by Thursday due to work schedule.

 

I would verify that the ECU/FI grounds that are on the upper intake D/S just by the Toyota ECU port are good. Not just a visual, grab the 6 or 8 brown wires and wiggle-tug on them one at a time and see if the wire eyelet spins. It isn't impossible for a wire to be broken internally and still look good on the outside.

 

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