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kvos40

kvos40

Joined
Jun 25, 2026
Threads
1
Messages
3
Location
howell michigan
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.
 
Search on here for “FSM” or “Factory Service Manual”.
I put a pdf copy on my phone for those days off grid.
 
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.
 
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.
1782424975227.webp
 
kvos40 said:
What’s the best place to inject the smoke?.
Click to expand...
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!
 
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.
 
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