mrhtkarl

A better picture.

Update: after replacing almost all vacuum lines there are significant improvements. At initial start up she idles terrifyingly low, i'm talking 450-550 at most and almost stalling. When i warmed her up at 2500 for 2 minutes and let it drop down, she smoothly went right to a 1000 prrrrrrrrrrrrrrrrrr. After a few minutes of driving she idles around 800, again fluctiating a bit higher and a bit lower.

Also when i take my foot of the accelerator she doesnt drop revs violently, she smoothly goes down.

In an ideal world i want her to idle at 1000 because she doesn't shake and runs more smooth.

Areas to still investigate:
1. Clean out throttle body
2. clean and check TPS
3. Replace fuel filter
4. Check Coolant temp sensor (already bought replacement from toyota so i might just replace it)
5. o2 sensors?


Ideas?

toyota4x4907

Hows the timing?
You said you have a bigger cam? Are the valves adjusted correctly for this cam?
Get the coolant temp sensor in and hooked up.

ChefYota4x4

iTrader: (5)

Make sure the CTSensor is bad, before replacement. You can return it, as long as you've not installed it... and it's nearly impossible to install it without them knowing. Were your numbers wonky on the CTSensor? Sorry, no time to read back much.... if you've already answered, ...forgaves me, lol.

Also, 1000 is too high, period. 750 on the dot for most is right on. And, when you're adjusting the Idle air screw out to 1000, or leaving it there, it's only seemingly better because you're adding more air, thus, more fuel is added to adjust and thus, ...it's masking whatever is REALLY wrong.

If your CTsensor IS in fact bad.... it's NOT going to run right, no matter what you do. Take the multi-meter reading and post it or compare it to the recommended specs, k? I can't remember the numbers, but around 2.5 on the 20k setting of your ohmmeter is right on for fully warm(176*F) So, fully warm it up, with the radiator cap off, thermometer in the coolant, and watch the readings and mark them down as it goes from 70degrees, to 90, to 110, to 130, etc., until it's fully warm. There are recommended readings for each of those temps in the FSM and even in any haynes.

If it's not idling up when cold, I'd immediately suspect your IACV. Mine NEVER idled up before when cold, ....tried a few donors, ...nothing. Got an OEM new, ....VOILA, it idles up perfectly to 1100 every time now, and gradually drops to let the EFI take over upon operational temp.

If it's jumping all over, I would suspect things like the AFM and TPS... did you inspect the resistance on those, thoroughly?(including the bench test for the AFM, swinging the measuring plate open, testing at the ECU, etc.?)... Or did you replace one/them? (again, sorry, no time to read back)

Disclaimer: I'm not sure on the recommended Idle for the 88... I know the resistance is different in the ECU and Injectors, ..but mostly it's the same. Have to look that up, but I'm pretty sure it's 750 for yours as well.

ChefYota4x4

iTrader: (5)

x2 on that. They appear to run better at 8* or so with a 261 or more cam. Might want to triple check the valve lash if you keep hitting dead ends. Even then, I can't imagine it would effect you in a way that would cause such erratic idle.

best wishes,

Mark

ChefYota4x4

iTrader: (5)

PS> if your idle is not dramatically dropping upon release of the pedal... that's good. However, if it's alarmingly slow to descend, ... I would try silicon on the Dashpot. If it's stuck, it can cause this really slow descent of rpms.

4crawler has a right up on this... 4crawler in google and a comma, then TPS adjustment(the dashpot info is in there)....It's also above in all the FSM info I've posted for you. lol