code 71 on a 91, check and replacement?

[jhfj80]

so i just replaced both o2 sensors this week on my '91 80 which took care of codes 21 and 28. but now i've got a code 71, which apparently is an egr problem. but MY problem lies with the bulls**t book that is known as the "Haynes manual." very undetailed analysis which seems to cover 400 years worth of cruiser models... but i digress.
does anyone have some advice on the best way to check the egr valve. should i test it cold, hot, half hot, half drunk?? also any beta on how much a new one costs? any help is greatly appreciated...
i'm fridge bound .....

 

[CJF]

MY problem lies with the bulls**t book that is known as the "Haynes manual." very undetailed analysis which seems to cover 400 years worth of cruiser models... but i digress.

On the contrary; that's not a digression at all. As you yourself said, that is in fact your problem.

Call here to fix it:

Toyota Publications 1-800-622-2033

 

[jhfj80]

cool, thanks for the number. guess i'll have to call back monday during "normal business hours." what a scam; don't they know I work during normal business hours... are the FSM's available at dealerships?

 

[CJF]

Hey, at least the call's free.

I think a dealer would just call them, same as you. I remember C-Dan saying he can't get them any cheaper than we can (or at least can't offer a significant discount).

Curtis

 

[jhfj80]

how much are they? and are there FSM's for each particular model year?

 

[CJF]

https://forum.ih8mud.com/showpost.php?p=1502793&postcount=6

See post #5 as well.

 

[jhfj80]

it says "above price quote..." but i'm not seeing it. what is the quote for a 92 manual? i can't imagine it's much different than that for a 91

 

[CJF]

When viewing my post, click on the link in the upper right hand corner that says, "Thread: '91 transfer case" or some such.

The price is much different, even though I'd be willing to bet someone else's money that the manuals are identical.

 

[semlin]

congrats, you have a california market only fj80. a certain crazy fj cruiser owner would not be jealous.

your truck has an egr temp sensor. the sensor has been triggered indicating either your system is blocked, your valve is broken or the vacuum system that activates the vale is not working. the first and last or most likely.

except for the location of stuff (e.g., egr valve is on driver's side of the engine) the egr system and hence the process to diagnosing and fixing it it is very similar to the 93-97. Take a look at the EGR Faq. you should check your egr modulator filter for carbon build up, inspect the vacuum lines and nipples for blockage, remove and check your vsv for egr (very easy on a 91) and remove and clean your throttle body and the ports on top of it that feed the egr vacuum lines. you also need to clean the passage from the egr valve into the intake plenum. you should buy an egr gasket and a throttle body gasket for this process. if there is carbon in your modulator filter (takes two secs to check) you should replace the modulator. You may need to replace some vacuum lines. It is possible but unlikely (last resort) that you will have to replace the egr valve itself.


good luck

 

[jhfj80]

thanks for the info semlin.... you'd think that a certain manual would be able to outline things that simply, but apparently i expect too much. i do have some nasty build up in the modulator filter and occasionally the single vacuum line on the one side of the modu will detach itself (fear of commitment??) and blow carbon chunks on the surrounding area. i'll try to do some more inspecting tomorrow.

 

[semlin]

ok well carbon in your vacuum lines screws up the vsv and prevents proper operation of the egr valve. it spreads everywhere so be prepared for all your vacuum lines to be blocked or contaminated and the throttle body ports to be blocked.

at minimum you now need a new modulator, and vsv for egr. plus i would replace the vacuum lines, especially the large one from the bottom of the modulator to the egr valve. you will also want to clean your throttle body ports and also see if the nipples on your egr valve have corroded and or blocked. then you need to pull the egr valve and check the intake plenum passage is clear.

after all that, if it still doesn't work you need a new egr valve as well.

 

[jhfj80]

so i was doing a bit of searching around here and found a way to bypass the egr system by basically looping it to itself and plugging a few holes (not as fun as it sounds). took her for a test drive and noticed an extra pep in the step. here in NC we no longer have to get emissions inspections for vehicles without an OBD2, which is good for me. but does anyone know if there are any long term effects of not using the egr system??