Topic: 85 runner pissing me off

[LAGEN WAGON]

Nope all suggestions thus far have been tried with no success. My brother in-law wants the sale of vehical finalized and I want to slap the lift under it that has so patientlly been waiting in my garage. I got some advice to take it to Yota Masters and we will see what they come up with. They seem to think something is up with the head work that whas previously done. I will keep all informed if any success is achieved.

Your problem lies in your front axle. Send it to me and I will give you a great running ifs out of an 86. That will fix the problem

Oh sure you betcha what a stellar deal you present. Here ya go!  

[fordh8r]

I reread the post top to bottom and I failed see if anyone had mentioned even checking the TPS.     Has that been checked for consistent resistance change with no opens through its sweep?  Hope this could help. 

[LAGEN WAGON [OP]]

Yep, it's in their somewhere and has been changed and adjusted accordingly. 

[RABIDYOTA]

when you checked you'r valve adjust. did you happen to look down at thje timing chain and follower. buddy 91 had a miss, chain streched ate a guide new timing set no miss.  just tossing things out.

[Tallchevy]

I read that you replaced the O2 sensor. Did you get it from Toyota? I would recommend getting one from Toyota. Were did you buy it from? Some times the after market O2 sensors have a wider range that the will adjust since they make them univeral to multiple engines. I have taken vehicles in to get smogged & they would fail, I've put in after market O2 sensor & still failed. Then replaced it with one from the dealership & it would pass. I'm just glad that it was company money I was spending & not my own for this trial & error. Might be worth a try.    

[LAGEN WAGON [OP]]

Well when the head cracked the timing chain was replaced with the head and it ran awesome for a few months or so. I did have a aftermarket O2 sensor and it has sense been replaced by a OEM sensor with no changes as far as it missing. It will pass smog if the timing is retarded to the point they cant legally pass it do to the timing being out of acceptable range,but that does not really help me. Keep em coming ideas still required being the master yoata shop is in disbelief.

[Loki]

so did you Bro-in-law actually get some info back from yota masters? what's did those guys have to say about it?

[tufsurf]

yota  masters  had not to say? 

[tufsurf]

do you know the history of the replacement head? maybe its high performance not meant for street.

[Marlin]

fordh8r got it right. Great answer.

It sure sounds like a EGR problem to me.

Did you in fact unplug the vacume hose at the EGR valve and then test drive the truck?

Our '85 one ton efi 2wd shop truck stumbles just like you have said and goes completely away when the egr hose is removed and plugged.
In the past, to overcome this problem, I have removed the valve and installed a washer with a smaller hole to restrict the exhaust flow.
Also have seen resticted egr ports on the efi mainfold.

Just my two cents....

Marlin

[Loki]

I believe he checked that, but are you trying to say that the air/fuel mixture is too rich and that by leaving a small orafice for air to flow this will lean it out?

[fordh8r]

Actually Marlin is right on, as well.  A universal EGR will come with different size orificed "washers" to adjust the metered amount of exhaust flow to the air fuel mixture.  So modifying a washer with a small hole will do the same thing. Just be sure that, if you have to smog your vehicle, you use as large a hole as your drivability performance will allow.  What size hole did you drill Marlin? do you remember? or was this just experimentation? 

I believe he checked that, but are you trying to say that the air/fuel mixture is too rich and that by leaving a small orafice for air to flow this will lean it out?

  In fact, the opposite is true.  With too large an orifice the mixture is lean because exhaust gas is known as being "inert" or not able to burn which lowers combustion temps thus reducing NOX emissions. so by lowering combustion temps the engine also runs cooler as well. All of a sudden blocking one of these off doesn't sound so great does it?    Nonetheless, By running a smaller orifice it reduces the amount of exhaust gas only enough to stop performance problems but not hamper it from an emissions stand point.   

fordh8r got it right. Great answer.

It sure sounds like a EGR problem to me.

Did you in fact unplug the vacume hose at the EGR valve and then test drive the truck?

Our '85 one ton efi 2wd shop truck stumbles just like you have said and goes completely away when the egr hose is removed and plugged.
In the past, to overcome this problem, I have removed the valve and installed a washer with a smaller hole to restrict the exhaust flow.
Also have seen resticted egr ports on the efi mainfold.

Just my two cents....

Marlin

Thanks, Marlin! Really, for everything! 

[Loki]

  In fact, the opposite is true.  With too large an orifice the mixture is lean because exhaust gas is known as being "inert" or not able to burn which lowers combustion temps thus reducing NOX emissions. so by lowering combustion temps the engine also runs cooler as well. All of a sudden blocking one of these off doesn't sound so great does it?   Nonetheless, By running a smaller orifice it reduces the amount of exhaust gas only enough to stop performance problems but not hamper it from an emissions stand point.   

That's why i asked...i thought it sounded odd.

[LAGEN WAGON [OP]]

Actually Marlin is right on, as well.  A universal EGR will come with different size orificed "washers" to adjust the metered amount of exhaust flow to the air fuel mixture.  So modifying a washer with a small hole will do the same thing. Just be sure that, if you have to smog your vehicle, you use as large a hole as your drivability performance will allow.  What size hole did you drill Marlin? do you remember? or was this just experimentation? 
  In fact, the opposite is true.  With too large an orifice the mixture is lean because exhaust gas is known as being "inert" or not able to burn which lowers combustion temps thus reducing NOX emissions. so by lowering combustion temps the engine also runs cooler as well. All of a sudden blocking one of these off doesn't sound so great does it?   Nonetheless, By running a smaller orifice it reduces the amount of exhaust gas only enough to stop performance problems but not hamper it from an emissions stand point.   
 Thanks, Marlin! Really, for everything! 

Makes sense....Worth a shot being the plugs are coming out a bit on the chalky side. I have checked for air leaks by fogging the engine with starter fluid...none found anywhere! AFM adjusted within specs. Thats why I suspected lean fire coming from one of the injectors. But with the new injectors installed still missed. I did run it with the EGR line disconnected cant remember if I plugged it though? But it still was missing?

Thanks Marlin and fordh8r for new avenues to explore.

Drilled out washer? Marlin, I would like if at all possible general starting point of the size of washer used and what size to drill it out to? Is this something that would require the trial and error methods?  Also where exactly to install this washer? Thanks!

[fordh8r]

?

Thanks Marlin and fordh8r for new avenues to explore.

Drilled out washer? Marlin, I would like if at all possible general starting point of the size of washer used and what size to drill it out to? Is this something that would require the trial and error methods?  Also where exactly to install this washer? Thanks!

You're very welcome!  Just to add, I've seen these orifices start at about 1/8 inch in opening size and increase in small increments up to about 3/8 or so.  The orifice should be placed at the EGR opening and should be held in place when the EGR is bolted on.  Use a small dab of grease if necessary to hold it in place while installing. Marlin would probably know better for the actual size needed since he did his for this reason. There may be  even a small recessed area where the orifice will fit in the EGR itself. Hope this works. if not then make it fit in the gasket opening so the EGR will bolt flat and not cause any breakage to the valve or problems with sealing. Good luck! 

[RABIDYOTA]

egr controler valve that stupid thing above right rear v/c bolt

[lucky7]

Did you ever get this fixed and how did you do it please.

[lucky7]

I don't know but i finaly got some codes my igniter and egr changed igniter seems too run better but still need to check egr to know if it's fixed.

[toyofan7987]

here in new york my 83 can pass inspection with no cat ... gottta love it.. plus most places will over look little things around here ... but no rocks just mud here