i bought an 86' pickup that was not running was told it wasnt getting fuel and the only item that was not replaced was the fuel injectors. And in fact found two were not working and got the truck running. But now it revs up and down both at idle and when given gas its also running rich. I have replaced all the vacuum lines, the pcv valve, the O2 sensor, have checked the maf, and adjusted the tsp and timing to try and correct this and have had no luck. The only bit of change is if i completly close the tsp and slow the timing which gives me a smooth idle at about 15000 rpm but no help when gas is applied. Any help????

 

15000 rpm!?. You still have a motor?...hehe

Welcome to YT.

Taking a stab...fuel pressure regulator? Or was that also replaced? Throttle linkage, then?

 

maybe it wasnt just a fuel issue but also a spark issue too...replace your rotor, cap, plugs and wires...gonna have to do it anyways

 

Not necessarily.

 

he said he bought at 86 runner that wasnt running, i would venture a guess to say that the plugs, wires, distro cap and rotor are old...and if they are not, well then he failed to mention that in his post...it may not solve his problem, but the maintenance will be handled.

 

You're right...they could be old. I see what you're saying. They could also be fine, though. It just sounded like an absolute statement. That's all.

So, I was doing some reading, but didn't get very far because the PC started acting up. How do those components cause a motor to surge like that?

 

mine did something similar. cold idle was ok, but when that dropped out the idle surged up and down. mines a 1990 22re. when the engine is cold more air is induced into the intake. it is routed through the holes bored into the bottom of the intake. there is a plunger under there that will close when the coolant circulating around it gets warm. same kind of principal as a thermostat. if those coolant lines going to this device (i believe it is called the air valve) get clogged up with goo...like mine, the plunger wont close therefore allowing too much air into the engine. to diagnose if this is your problem, pull the intake hose off of the throttle body. look in your throttle body and you will see 2 or 3 holes on the bottom side. cover them with duct tape. re install intake hose and see how your idle behaves now. might have to adjust the screw for the idle too. be careful with the duct tape, make sure it is secure, it will eventually try to suck it into these holes. my long term fix was a piece of aluminum from a beer can (not just good for holding beer anymore) then duct tape over that.
one other thing i just thought of.....i believe i read that if the idle screw is set to high it will do this....if i am not mistaken if the idle is set too high the computer shuts the fuel down, like it does when you are braking. basically i think if the idle is set too high it confuses the computer.
keep in mind this is a 22re, and the only toyota i have some experience with.
hope this helps

 

i also have new plugs and wires and fairly new cap and rotor. And the problem seems to be more of too much fuel not too little air. Any suggestions on how to check the fuel pressure regulator.

 

you probably have a vacuum leak. try to get it running then spray down the egine compartment with starting fluid while the motor is running. If the rpms surge more than usual you have a leak somewhere. this will help you locate it at least.


Jon

 

Or you could use an unlit propane torch aimed around all you vacuum lines and fittings. If it surges, there's the leak. Starting fluid would also work using the same procedure as this.

 

read the orignal post i have all new vacuum lines and the problem seems to be that i am getting to much fuel.

 

I know. But, it doesn't mean you don't have a vacuum leak somewhere else other than lines. That's all. And hopefully you have them all rerouted correctly?

The fuel pressure regulator...I forget exactly how that's done, but it's real simple. Type fuel pressure regulator test in the search bar. I know it's explained in detail in the multitude of threads on this forum.

 

EGR valve stuck open or leaking.....
or replace MAF

 

BTW, mudslinger, you wouldn't have a Mass Air Flow sensor with that year pickup. You will have an Air Flow Meter. It might help you to know this when you're working things out in the future, as well.

Have you gotten anywhere with it?

 

well what ever it is it does the same thing as far as i know. And i have a few things that im not supposed to because it had a engine swap with a newer vehicle. where do i find the plug to check mal codes my book say near the ignition coil but i dont see it. And no i havent gotten a chance to do much this weekend. Had a party on sat and my anniversery was sunday so maybe tonight.

 

Yo,
Jumper the diag port and see what trouble codes you get.

Does vacuum line to fuel pressure regulator go directly to a vacuum port?

Too much fuel is likely fuel pressure regulator and or Mass Air Sensor. Search the web for all this information. I think autoshop101.com has sections from the factory manual.

Keep us posted.

 

Yeah, they do basically. In past threads I've read, it has just created some confusion mixing the two up especially when using the terms as a keyword in a search. They are designed differently and so repair or replacement is different.

Anyhow, there are two dummy plugs, yellow in color, near the air box. One is bigger than the other. The smaller one will have two plugs holes. Jump those with a paper clip and turn the key on to ignition. The CEL will come on and flash a code, if there are any. Then, count the number of flashes it gives off. Compare with this here chart:
http://www.off-road.com/toyota/tech/codes/index.html

Note: It says the plug is green on this site, but my '86 has a yellow one and yours may also.

 

i mal codes for the airflow meter, tps, intake air thermo sensor, and knock control sensor. any ideas on where to start. i belive the tps is because i had blindly adjusted it to see if that would make a difference. The airflow meter i was told was working by a trusted mech. intake air thermo......no clue what that even is and no luck finding it in my book. And the knock control well one problem at a time and from what i understand it could just be bad. but shouldnt cause my problem.

 

One quick test I have learned is to disconnect the TPS and see if that affects how it is running. If it's a problem, it should run a bit better. Then, you can test it with an ohm/volt meter to determine conclusively, if you want.

The thermo sensor is inside the air flow meter. Here's a link:http://personal.utulsa.edu/~nathan-b...33volumeai.pdf

So, what are the code numbers it's throwing?

 

coolant temp sensor??