First post in a long time on MUD, used to spend most of my time in the 60 series forum 
. Bought a 91 pickup from a friend last year that I've been trying to get back on the road and have been banging my head against the wall for way too long.
It ran well when I bought it after sitting for a couple years. New battery, new gas and some seafoam worked its charms. The front suspension was HORRENDOUS, but I drove it to take trash to the convenience center on backroads last spring. Only issue was a stutter after shifting into 4th and 5th which I attributed to needing a tuneup, filters, etc.
Pulled the passenger front suspension apart in June. Replacing UCA and LCA bushings, shock, ball joints, sway bushings. Took longer than I wanted because I found that whoever installed the ball joint spacer lift hacked the UCA's up terribly. Got new UCA and corrected it. Everything on that side is back together awaiting proper torqueing.
While it was on jacks, I had been starting it every week or two to run for 30mins. No issues starting until about July/August last year. Our summer got terribly hot and I don't have a garage so I didn't get back to working on it much until the fall. About mid-summer I went out to start it and it just wouldn't start. Cranked and cranked all day but no fire. That is where I still stand today.
Trying to make it brief:
Ignition on - No CEL
Jump pins in OBD1 plug- No CEL
Checked IGN and Distributor coils and all were in spec in late summer. I have a parts 95 4runner and tried the igniter and coil from there, no change.
Check, cleaned grounds/mounting bolts on IGN
Cleaned ground under throttle body on head (other end of IGN ground wire)
Cleaned ground where battery main attaches behind steering pump
Checked harness next to UCA bolts in case I smashed/broke anything during suspension work. One wire, small black-brown, had hard twist but didn't appear to be broken. Can't confirm what it is from manual
Pulled ECU, checked mounting points, checked cables for tightness. Checked power with IGN on, white-red wires, are good. Brown grounds are good. Tried to ground CEL from plug at ECU "If you have a manual trans then the seventh wire from the bottom right should be violet and comes from the check engine light" from another forum. There are two violet wires but aren't anywhere near the 7th position.
Checked B+ at diagnostic port and have power with IGN on (second check that ECU is getting power)
Checked Fp port on diagnostic port with IGN on and fuel pump has power
**this should mean that ECU is at least semi-functional, but it has power and no spark or tach signal**
Checked all fuses and relays, all good
Pulled cable from VAFM with no change. Have power to VAFM, when I spin the dial (top is off) fuel pump runs. Cranking with VAFM held open, can smell fuel
Ignition coil has +12v on both wires with IGN on. Igniter has power too (when coil is plugged in)
Still no tach pulse, no CEL, no spark.
If it was just the tach and spark, I would definitely be deep diving into the distributor/igniter wiring. The CEL issue is really bothering me. My Haynes manual diagram is little help. The only ignition wiring diagram is for 4cyl engines. Online resources, every pinout and color for the wiring is different and none match mine. I feel like I'm honing in, but not able to see anything to lock in on the problem. I just want it to run so badly! My guesses are #1 damaged wire somewhere due to my other work, #2 ignition system fault, or #3 failed/partially failed ECU. My 4runner is an auto so I don't think I can swap that ECU to test??
I hate the 3vze but love this truck and the frame and body are in great shape. I'm hoping to 2JZ swap it (or 2UZ??) but wanted to drive it with the v6 for a bit if possible.
Any help is appreciated!
Thanks
-Matt
. Bought a 91 pickup from a friend last year that I've been trying to get back on the road and have been banging my head against the wall for way too long. It ran well when I bought it after sitting for a couple years. New battery, new gas and some seafoam worked its charms. The front suspension was HORRENDOUS, but I drove it to take trash to the convenience center on backroads last spring. Only issue was a stutter after shifting into 4th and 5th which I attributed to needing a tuneup, filters, etc.
Pulled the passenger front suspension apart in June. Replacing UCA and LCA bushings, shock, ball joints, sway bushings. Took longer than I wanted because I found that whoever installed the ball joint spacer lift hacked the UCA's up terribly. Got new UCA and corrected it. Everything on that side is back together awaiting proper torqueing.
While it was on jacks, I had been starting it every week or two to run for 30mins. No issues starting until about July/August last year. Our summer got terribly hot and I don't have a garage so I didn't get back to working on it much until the fall. About mid-summer I went out to start it and it just wouldn't start. Cranked and cranked all day but no fire. That is where I still stand today.
Trying to make it brief:
Ignition on - No CEL
Jump pins in OBD1 plug- No CEL
Checked IGN and Distributor coils and all were in spec in late summer. I have a parts 95 4runner and tried the igniter and coil from there, no change.
Check, cleaned grounds/mounting bolts on IGN
Cleaned ground under throttle body on head (other end of IGN ground wire)
Cleaned ground where battery main attaches behind steering pump
Checked harness next to UCA bolts in case I smashed/broke anything during suspension work. One wire, small black-brown, had hard twist but didn't appear to be broken. Can't confirm what it is from manual
Pulled ECU, checked mounting points, checked cables for tightness. Checked power with IGN on, white-red wires, are good. Brown grounds are good. Tried to ground CEL from plug at ECU "If you have a manual trans then the seventh wire from the bottom right should be violet and comes from the check engine light" from another forum. There are two violet wires but aren't anywhere near the 7th position.
Checked B+ at diagnostic port and have power with IGN on (second check that ECU is getting power)
Checked Fp port on diagnostic port with IGN on and fuel pump has power
**this should mean that ECU is at least semi-functional, but it has power and no spark or tach signal**
Checked all fuses and relays, all good
Pulled cable from VAFM with no change. Have power to VAFM, when I spin the dial (top is off) fuel pump runs. Cranking with VAFM held open, can smell fuel
Ignition coil has +12v on both wires with IGN on. Igniter has power too (when coil is plugged in)
Still no tach pulse, no CEL, no spark.
If it was just the tach and spark, I would definitely be deep diving into the distributor/igniter wiring. The CEL issue is really bothering me. My Haynes manual diagram is little help. The only ignition wiring diagram is for 4cyl engines. Online resources, every pinout and color for the wiring is different and none match mine. I feel like I'm honing in, but not able to see anything to lock in on the problem. I just want it to run so badly! My guesses are #1 damaged wire somewhere due to my other work, #2 ignition system fault, or #3 failed/partially failed ECU. My 4runner is an auto so I don't think I can swap that ECU to test??
I hate the 3vze but love this truck and the frame and body are in great shape. I'm hoping to 2JZ swap it (or 2UZ??) but wanted to drive it with the v6 for a bit if possible.
Any help is appreciated!
Thanks
-Matt
!
