Hey everyone! I have been having an absolute hell of a time tracking down the issue with my pickup, so I wanted to run the problem by everyone on these forums to see if anyone has experienced anything similar.

I have a 1989 Toyota Pickup with a 22re, 4wd, standard cab. The problem starts when I run too many electrical items at one time. If I have the headlights/windshield wipers on, or the heater, or use my blinkers/brake lights in combination with any of the other electrical items the engine develops an extremely bad miss. To the point where it will miss so bad at stop lights it will sometimes die on me. If I turn off all of the electrical items however the truck will run fine.

I just finished tearing the entire dash out and inspecting every ground and connection that I could find, and that doesn't appear to be the problem. I have replaced all of the battery cables/connections/terminals as well as the alternator/cap/rotor/plugs/wires. Previously pulled out all of the stereo and aftermarket type electronics to make sure nothing that I did was the issue.

The problem developed and worsened over time, only recently getting bad to the point where I couldn't keep it running at stoplights at night. I honestly have no idea what it could be, but I am open for ideas. Relay somewhere? ECU maybe? Thanks in advance for the help!

 

Sounds pretty simple

Your charging system is for what ever reason maxed out.

Time to break out the meter!!

With only a limited amount of watts in the system when at idle it drops lower the ecu shuts down in self defense to save it`s self.

I am not sure off the threshold voltage a guess would be @ 10.5 VDC

Voltage readings at the battery

***The wire from the B terminal of the alternator if not replaced over the years gets cooked from the thermal cycling to the point it barely conducts.

Was this one replaced

What was used to replace the battery terminals and cables??

 

Check the 2 grounding straps. One at the back of the valve cover to the body and one at the ground terminal at the battery to the body (short wire). Also there are 2 or 3 ground wires for that are on a loop terminal that get grounded to the intake manifold where the 2 sections bolt together. make sure they are clean. Also check the ecu fuse for corrosion.

 

Hey guys! Thanks for the great info!

The battery cables and wires were all replaced with 4ga battery cables with all new terminals and everything. I did not however change out the wire that ran from the alternator when I installed the new alternator. I will for sure replace that now!

I will also double check all of the grounds mentioned above to make sure I didn't overlook any of them that you mentioned. Thank you again for all the help and Ill let you know if any of that takes care of the problem, thank you!

 

4 AWG is pretty small!!

I use 1/0 welding cable for the positive cable and the main ground wires

You really need to get voltage readings so you have an idea what is happening .

 

Yes, both ^^^ are CRUCIAL. See how charging system works on link below.

This is exactly how I, Chefyota, and Redeth connected our upgraded alternator to battery wires, except that the two other gents used thicker wires and bigger circuit breakers/fuses on their rigs.

 

What alternator did you use ??

Why 6awg instead of 4awg ??

you do take nice pictures!!

 

Tnx
Just stock toyota alt with stator upgraded to 90-amps.

 

Do the meter stuff first.

The stock wiring is plenty to keep the headlights, heater, wipers, brake lights, etc. all on at the same time. So you have something that is no longer as good as stock. I doubt it's the alternator B-wire; either it's open (so doesn't charge the battery at all), or it's "high" resistance (so it charges the battery UNTIL you turn on the accessories, and the accessories drive off the battery -- for a while.) I suspect you have a bad connection somewhere in your "new" wiring. And the voltmeter will point you right to it.

If you feel the need to replace any of the wiring (like the alternator B-wire), upgrading to something like 6AWG doesn't hurt anything. But unless you're running an arc welder from your cigarette lighter socket, anything bigger is overkill.

 

Concur.
NEXT TO OUR SENSES (Common included), the MULTI-METER is the best electrical diagnostic tool. There's no excuse for not having one. HF is your friend.

AND, O.P.,
You replaced everything but you never mentioned if you had your battery and charging system tested.