89 4runner...running problems

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

dlucky894runner

dlucky894runner

10 Year
Joined
Jan 6, 2011
Threads
11
Messages
76
Location
Springville, UT
I just completed a head gasket, Timing Chain, etc on this new to me truck. It starts with the first turn. It idles great. As soon as I start introducing throttle into it, it bogs and dies. The truck has sat for at least one year and the gas tank is full. The truck is throwing up a code 31, which from research is the AFM/Vacuum signal. What do I do to fix this? Any other things that could be causing the throttle bog and dying?
 
Yup...Did that. All sealed up and tight. I bought this as a DD for a new job, so I need to get it up and driveable. Anymore help would be appreciated.
 
Thanks. I haven't tested the AFM, yet. Just read up on how to test it today. Will do that tonight. I did purchase a used one and put in on and it didn't change anything. I changed the fuel filter when I had the intake off for the HG replacement. I figured something that buried I didn't want to have to deal with it at a later time.
Anyone have any experience with the fuel pressure regulator? Think that could be the cause? Bad gas? I haven't done much work on these newer vehicles with all the emission/vacuum stuff. I am used to my 72 Chevy where it's a lot more simple.
 
I'd bet the AFM is bad. It directly influences fuel flow to the engine. It could also be the wiring to the AFM. Check the contacts in the connector at the AFM first.
 
Will check them out this evening. Spray some electrical contact cleaner on the connectors.
Thanks for the help.
 
If the regulator has gotten weak it could be lowering the pressure in the fuel rail feeding the injectors... But I can't say I've heard of it ever happening... if you are getting a AFM code, and changing the AFM didn't help, I'd say better check the wiring really well... trace all the wires back to where they connect, probably most go to the ECU.... Happy hunting! :cheers:
 
Thanks. I just found your thread on a very similar problem. I will double check my timing, also. Do you remember any codes being thrown when you had your problem?
 
Well, tested the AFM, and it tested good. All of the readings were in line with the FSM. The truck will idle for hours if I let it. As soon as I introduce throttle it starts jumping up and down and then, if I throttle it too much, it dies. I traced all the wires back to the firewall on the passenger side. I have double, triple, checked the timing. It is on as good as it can be. I am totally lost as to what to do. Is it time to take it to Toyota? I hope not. I don't have the cash to do that.
 
FSM says:
#1: AFM
#2: EGR
#3: TPS
#4: Spark Plugs
#5: Fuel Pressure Regulator
#6: Fuel Lines
#7: Injectors
#8: ECM
 
Thanks. I have downloaded an FSM from one of those links. The one problem I am finding with the FSM's are that they don't have a lot of diags and pics for the 22re-C. California emission crap. That is what I have and there are a ton more vacuum lines than a regular 22re. Hope to try some things this evening. My major problem, probably just my thinking, is why the truck would through an AFM code if the EGR, TPS, or something else is bad? Just doesn't make sense, but I am fairly new to all this emission stuff.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom