87 Toyota pickup/motorhome mystery issue


#1

22RE engine, ran like a top, now it starts fine, runs for 2 seconds then stalls like someone turned the key off. This is repeatable. Fuel filter and pump are fine, sparks look good, injectors check out fine, igniter replaced - no help. The first mechanic was stumped. The second mechanic thought it was the igniter but it isn’t. I live in this full-time and really need it running again, Any thoughts?


#2

Check the ballast resistor.

https://www.rockauto.com/en/moreinfo.php?pk=479309&cc=1277502&jsn=367

The ballast resistor allows full voltage to the ignition coil when starting the engine. Then once the engine starts, the ballast resistor drops the voltage to the coil. This is done to prevent the secondary ignition components from being fried when the charging system comes on line.

Tester


#3

Does this happen every time you try to start it?

Does it run for 2 seconds or does it die as soon as you release the key?

Sounds like the ignition switch is bad to me.


#4

My best guess is the fuel pump relay (circuit opening relay) has failed.

https://www.google.com/search?q=1987+Toyota+Hilux+circuit+opening+relay&client=firefox-b-1-ab&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwiKsqybpvfdAhUMXa0KHTk3DlYQsAR6BAgFEAE&biw=1428&bih=779#imgrc=kLE8L6BaSoBHRM:


#5

I’ve had vehicles with a ballast resistor, but I don’t think this 87 with a 22REC engine has one. As I remember, if the resistor is open, the engine will stall when the ign switch goes from start to run. But in my case, the engine runs fine for 2 seconds when you release the ign switch. Odd behavior. I’m starting to suspect the ECU.


#6

It does happen every time. It will run fine for about 2 seconds after you release the key. Odd behavior. The only thing left to try I think is swapping out the ECU.


#7

I can keep the engine going, sort’a, by manually pulsing the Cold Start Injector and modulating the gas pedal. It runs rough but does run this way. And the fuel pressure is 40lbs at this time (and you can hear the fuel pump running… it’s an outside-the-tank pimp). So the relay is probably okay. I’m wondering if it’s the ECU. The obsolete ECU. That’s the next thing the mechanic wants to try.