help with code 84

[86 ranger]

i pulled the code 84 on my 1986 with a 2.3. the book said it is egr vacuum regulator circuit failure. the truck runs good except at times when i stop it will shake at idle and die. have done complete tune up.any help would be great. thanks. tracy

 

[Wicked_Sludge]

sounds like your getting EGR flow at idle, which you shouldnt be. does that year still use a DPFE? if so, its a common failure item and would be worth looking into.

but first, i would unplug and cap the vacuum line to the EGR valve and drive the truck to see if it cures your lumpy idle and stalling problems. if not, your valve is stuck. if it does fix it, you have regulator issues.

 

[86 ranger]

thanks, i will plug off the line and give it a try.

 

[86 ranger]

i drove it today with the vacuum line off. it still died a couple times. whats next to try.

 

[Wicked_Sludge]

check for EGR operation.

with the truck idling and the same vacuum line removed, apply vacuum to the EGR valves port and watch the pintle, you should see it move and the engine should start to idle poorly, maybe die. when you release vacuum, the pintle should close again and the idle should smooth out.

after that, pull the valve off and inspect for excessive carbon build-up that may be causing the valve to not close fully. if this is the case, i'd just replace the valve (rather than trying to clean and re-use it).

 

[feellnfroggy]

Take off the throttle body, there is a black hose about 1/4 in. in diameter. This tube gets plugged with carbon like mine did. Alot of gas and brake cleaner and a dremel. it needs to be unclogged. if that dont work it the idle air control.

 

[86 ranger]

thanks, i will try both ideals and let you both know. tracy

 

[86 ranger]

today i replaced the air idle controler and the egr relay. i now have vacuum at 3000 rpm to the egr. it still dies some times when i stop in gear. i put a vacuum guage on the egr valve and applied vacuum to it. the pindle did not move. i am going to buy a new egr valve and try that. will post results when done. thanks. tracy

 

[feellnfroggy]

today i replaced the air idle controler and the egr relay. i now have vacuum at 3000 rpm to the egr. it still dies some times when i stop in gear. i put a vacuum guage on the egr valve and applied vacuum to it. the pindle did not move. i am going to buy a new egr valve and try that. will post results when done. thanks. tracy

I forgot to mention, I had a bad MAF too.

 

[86 ranger]

it was a stuck closed egr valve. i took it off and got it loose. it runs good so far. if it sticks again i will get a new one. about 134.00 for a new one. thanks for all the help. tracy for the help

 

[Wicked_Sludge]

glad you got it figured out