New guy.

[kvos40]

Hey guys! Just got a 91 FJ80. She’s super clean and I got it for a steal. Guy said it ran rough when cold. And idled high. And that all started when the exhaust fell off after the cats. This week I started it up and when I put it in drive it died and took all day to start back up. When I pulled the plugs they were super wet so I assume it’s running really rich. I know the induction tubing is all ripped up so I have one coming from city racer. In my trouble shooting I noticed that the connector to the Vacuum switching valve had one of the wires broken off I assume this isn’t helping my cause. This vacuum sys is crazy so I’m open to tips.
One quick other question I’m looking for the maintenance Manual and a wire diagram manual. But I’m not having much luck. I’d pay for em if I had had to.

 

[Roostre]

Search on here for “FSM” or “Factory Service Manual”.
I put a pdf copy on my phone for those days off grid.

 

[80serie]

Check in the « Resources » section you’ll find everything you and more!
Do a smoke test to check if you have vacuum leaks. You can see how to make a smoke tester for $10 on internet in case you don’t have a smoke machine.

 

[Marco Lau]

Sounded like the engine has been neglected for quite some times, and not trying to rain on your parade, these are 35+ yr old car and it will take some effort to bring it back to top notch form. The 3F-E is very particular when it comes to sealing the upper part of the engine. Like 80series said, do a smoke test, and i bet you have tons of vacuum leaks especially with the intake elbows, emission related vacuum lines, etc. Other than cap/ rotors, plugs, wires, and fluid change, get a new fusible link, make sure you have spark, air and fuel. Here is a vacuum diagram under the hood for reference.

 

[kvos40]

You guys rock!

 

[kvos40]

What’s the best place to inject the smoke?.

 

[jonheld]

I will add, use OEM parts under the hood.
The Toyota FSM and EWD are invaluable to have.
Some documents for your enjoyment:

https://forum.ih8mud.com/resources/3fe-efi-diagnostics.89/

https://forum.ih8mud.com/resources/3fe-tune-up-info.90/

https://forum.ih8mud.com/resources/3fe-belt-routing.95/

 

[80serie]

What’s the best place to inject the smoke?.

In my case I did connect right after the MAF (VAF in your case). Original rubber loose their suppleness after 30 years and get hard and brittle. The retaining clips are not strong enough to overcome the hardness of the rubber and therefore leave gaps and create vacuum leaks. It does not take much to pass from a rough running engine with poor performance to a smooth one.
If I may suggest, in your quest to a smooth running engine, strart your investigation from simple things before to dig deeper. You’ll save time and money.
Good luck!

 

[MissahPapaJ]

Bout them wet plugs pull off the vacuum line for the fuel pressure regulator and make sure it’s not leaking and getting sucked into the intake easy and not time consuming to check, check at idle and at 1500 rpm if fuel isn’t coming out move one. Do yourself a favor and order a roll of OE Toyota vacuum line ( aftermarket isn’t sized the same and looks lame ) do one at a time so you don’t end up mixing things up.

 

[kvos40]

ok so i smoke tested the egr side and got smoke from the top of the egr regulator and from the top of something that's connected to the thermostat manifold? is it supposed to do that? i also changed the AFM and it seemed to idle more regularly but was stuck in this loop of almost dying out then would rev its self up super high. im thinking a de smog is in my future. anyone have any desmog tips? im pretty mechanically inclined but this thing is kicking my ass

 

[kvos40]

Update. I smoke checked the whole vacuumed system she’s tight. I changed the IAC valve. I changed the fuel press regulator and damper I also changed the fuel filter. It seems as though ever step i take it get worse. She barely even starts now and it smells like raw fuel out of the exhaust. I’m gonna go for the ignition system now. I’m gonna a change the dizzy. I have a coil for it as well. One thing I didn’t think about was ground. Does anyone have a good picture of the chassis grounds? Also I got an egr kit I’ll be throwing at it as well. I was able to get it running nice for just a min after disconnecting the fuel press regulator vacuum line but idk if that was coincidence or not I’ve not been able to duplicate that. I’m open to ideas. Or if anyone is close to Michigan and would like to lend a hand.

 

[ceylonfj40nut]

! This thread needs some pics!

 

[80serie]

Injectors maybe! After 30 years you can be sure that the orings are hard and brittle and they may not seal well. Or a stuck open injector. But maybe it’s better to rule out more accessible parts before to tackle this job.

 

[Marco Lau]

if your plugs were wet, you have a fuel issue. Most likely not injectors, but check the FPR or pulsation damper on the fuel rail. the FPR operates off vacuum and switching, so make sure the vacuum lines are in good shape and the solenoid connecting to it and the source of the vacuum, aka the intake manifold.

 

[jonheld]

Update. I smoke checked the whole vacuumed system she’s tight. I changed the IAC valve. I changed the fuel press regulator and damper I also changed the fuel filter. It seems as though ever step i take it get worse. She barely even starts now and it smells like raw fuel out of the exhaust. I’m gonna go for the ignition system now. I’m gonna a change the dizzy. I have a coil for it as well. One thing I didn’t think about was ground. Does anyone have a good picture of the chassis grounds? Also I got an egr kit I’ll be throwing at it as well. I was able to get it running nice for just a min after disconnecting the fuel press regulator vacuum line but idk if that was coincidence or not I’ve not been able to duplicate that. I’m open to ideas. Or if anyone is close to Michigan and would like to lend a hand.

Is it throwing any error codes?
Have you downloaded the FSM?
Are you testing sensors and parts according to the FSM before replacing?

 

[kvos40]

if your plugs were wet, you have a fuel issue. Most likely not injectors, but check the FPR or pulsation damper on the fuel rail. the FPR operates off vacuum and switching, so make sure the vacuum lines are in good shape and the solenoid connecting to it and the source of the vacuum, aka the intake manifold.

I changed the FPR and the Damper. I’m going to do the Desmog doesn’t the get ride of that switch and vacuum lines??

 

[kvos40]

Is it throwing any error codes?
Have you downloaded the FSM?
Are you testing sensors and parts according to the FSM before replacing?

I pinned out the OBD 1 and got some code for coolant temp. I wasn’t really sure where to go with that and didn’t think I could cause this. I have the FSM. Honestly I’ve kinda just been shot gunning parts hoping it would change something but I’ve not had luck.

 

[kvos40]

I’m trying to add a video but it may not let me from my phone.

 

[jonheld]

I pinned out the OBD 1 and got some code for coolant temp. I wasn’t really sure where to go with that and didn’t think I could cause this. I have the FSM. Honestly I’ve kinda just been shot gunning parts hoping it would change something but I’ve not had luck.

You're dealing with 1986 technology. There's no magic here. Listen to what the truck is telling you. Throwing random parts at it is not going to fix your issue.
The ECU runs the show. But it's only as good as the sensors that are feeding it. If it's getting bad information, it's not going to run right.
Follow the FSM and do the proper tests.

Always remove the 15 amp EFI main fuse from the under hood relay box on the left fender after changing any parts under the hood. This essentially reboots the ECU, clears any stored codes, and gives it a chance to relearn all the sensors.

 

[kvos40]

You're dealing with 1986 technology. There's no magic here. Listen to what the truck is telling you. Throwing random parts at it is not going to fix your issue.
The ECU runs the show. But it's only as good as the sensors that are feeding it. If it's getting bad information, it's not going to run right.
Follow the FSM and do the proper tests.

Always remove the 15 amp EFI main fuse from the under hood relay box on the left fender after changing any parts under the hood. This essentially reboots the ECU, clears any stored codes, and gives it a chance to relearn all the sensors.

I don’t have some of the tools to test electrical parts. I got a basic multimeter and that’s about it. Thanks for the EFI relay info.