89 yota pickup beast

I have one of the most tricked out old Toyotas (in my opinion) and its been rock solid, hasn't broke down in 25 years....until recently. It will randomly shut off out of nowhere, and randomly just not start. Impossible to diagnose bc its so intermittent and i checked all the normal stuff.

one time it will die when im crusing at 55 on the hwy, next time it will die when im redlining it on the trails. When it shuts off it never starts right away, but always eventually starts back up. sometimes 2 minutes later, sometimes not til an hour later. it cranks but the engine doesnt turn over. same deal with when i go to start it after being off and it wont start, i just keep trying every few minutes and then its good.

this issues will happen multiple times in a day, and then not happen for months, its been maybe a year. it feels like its happening more frequently now tho. and no sometimes when it does start, it will runs super rough for 10 seconds sounded like its dying idling very low, when i try to gas it to get the rpm up it does not respond. sometime it stalls after 10-15 seconds, sometimes it starts running fine and has no further issues on the drive.

one time i was able to pull the coil wire off the ignitor and held it close to try to start to check for spark after it wouldnt start...there was NO SPARK. so i replaced the coil and ignitor thinking i found and fixed the problem. but no, it still happens.



I have 2 new batteries in parallel with voltmeters. i replaced the fuel pump with a year or 2. the coil and ignitor are brand new.



it sounds like a spark or electrical issue when it shuts off or wont start, but is there anything further upstream from the coil/ignitor to causes the issue?

but when it runs rough and acts like its stalling out it sounds like a fuel issue. im super stuck on this problem bc its so intermittent and i can never have it in a shop when its acting up.



my dad is a 50 veteran mechanic and im an engineer, we been able to figure out everything else o this bad boy. this is my 1st time on a forum, hoping a veteran out there has dealt with this problem, thanks!!

Robert m

iTrader: (2)

Is it a 22R or RE?

When it stalls out, does it sputter and choke out or instantly shut off?

Have you checked fuel pressure? How old is the fuel filter?

Have you checked for any engine codes?

89 yota pickup beast

its the 3.0 V6. fuel pump was replaced maybe 2 years ago. Fuel filter is my best guess right know. i thought i replaced it with the pump, but i didnt, not sure how old it is. ill check that next and send an update.

no check engine light comes on.
when it stalls it sounds like its thirsty for fuel or air and sputters.
but when it doesnt start, i checked for spark and wasnt getting any...
thinking of hooking up a fuel pressure gauge and some type of meter to monitor spark. so when it acts up I can have visuals on what im losing.

Is there some meter I can hook up too see if im actively getting spark or not??

13Swords

Long shot but how about the Pickup Coil in the distributor? If you're running the original distributor or it's an older unit this could be a cause. The wires in that coil fatigue over time from heat cycling and could be causing higher resistance, which will impede any signal it's trying to send to the igniter. This problem can act just like an ignition coil going bad. Cutting out when it gets hot, & only allowing a restart once the coil cools off & resistance drops enough for the signal to reach the igniter.
Get an ohm (resistance) meter, unplug the lead for the the pickup coil at the distributor & measure the coils resistance. It should be between 140 to 180 Ohms cold. I'd say anything above a reading of 160 is suspect, as the resistance will only go up with heat on a fatigued coil.

The coil hold-down screws could also be loose and the coil be out of adjustment to the reluctor ring on the distributor shaft. If it's moving around a bit that could explain the intermittent problem.
The air gap spec should be 0.008" to 0.016". Use a feeler gauge to check this. BTW on the V6 distributor there are TWO pickup coils so check them both for resistance & air gap settings, & make sure they are not moving around.

89 yota pickup beast

Update: I shifted my attention back to the fuel. Was finally able to find a banjo bolt to hook up a fuel pressure gauge. went to start it and nothing happened, showed 0PSI. 10 minutes later tried again and randomly fired up but ran very rough and sounded suffocated for fuel, the gauge read 4PSI. it slowly started to crawl up, 6PSI, 8PSI, 10PSI about 30 seconds later and the idle went to normal. It kept rising over a minute or 2 to the correct 38PSI. I checked the wires running to the fuel pump and they read 12-13V.
Ever heard of or know what would cause the pressure to slowly rise like that?

So it sounds like the fuel pump is going bad, but Im having a hard time believing that because i put on a Toyota OEM one 3 years ago. The original fuel pump was almost 30 years old and still worked, i just replaced it because i had the bed off already.

13Swords

Another thought. The intermittent character still points to an electrical issue. Consider the circuit opening relay, or COR. It is a part of the fuel pump's electrical circuit, "upstream" of the pump and send power to the pump. If the contacts in it are burned, pitted or just plain worn down, this could be it.
Again, if it's original it's 32 years old and could be an issue.
There's plenty of posts on this part on Yotatech, just search for it.
Here's some basic info on design & operation: http://wilbo666.pbworks.com/w/page/4...pening%20Relay
On your '89, it should be located behind the passenger side kick panel.