[citadel]

add me to the list.. completed the mod today.. the gauge rises a lot slower after cold start up and has been settling in at the half way point... it is well over 90 here in Texas so I will take the mid point position of the gauge as a good sign....

[landtank]

Originally Posted by BenMara

ok did the resistor mod. at idle and around town its about half way, a lil below or above. now when i get goin on the highway about 60-75 it creeps up about 1-2 widths before red.
Should i be worried?

Yes you should. I'd look into your fan clutch.

[80t0ylc]

Thanks RT, for this very helpful thread and all the research and effort by you and all who contributed. Cost was minimal (little over $3) thanks to Davework who organized a buy and delivery. I'm now very familiar with the "black hole" behind the steering wheel. Being as mine is a '94, I combined your dash dis assembly with my FSM and it worked out ok. FSM called out to remove heater duct #2, combination switch & turn signal bracket. None of which was necessary to remove. My steering column cover is in such poor shape, it was the biggest challenge & source of much frustration.

I'd suggest using a pair of hemostats (they're like a locking pair of needle nose pliers) for bending the resistor leads and as a heat sinc while soldering. They'll help you be able to custom bend the resistor leads exactly as you want. Also, the use of resin core solder will clean the joints as you solder for better results. Do not use acid core - that's for making plumbing joints.

I couldn't find the "extra credit" characters on my gauge plus I couldn't read the one I was supposed to add, so that was a wash. I wished I'd had more artist skills so I could put the new temps at the right spots on the face of the gauge. Maybe a decal could be fabbed by someone with the right connections, for future newbies digging in to it.

Thanks again to all who helped!!!

[RavenTai]

nice work guys,

there was some talk about a decal for a while, the repeatability of the mod is decent but not perfect bringing the precision of any markings into question

[Cruiserdrew]

Yeah, but Raven you deserve MAJOR props for this. I love being able to know at a glance what's going on. Once done, it totally changes the way you look at your temp gauge. It is helpful to calibrate with a scan gauge, but once done it's amazingly repeatable.

[JerseyCruiser]

I have a 93 with the 100/150 resistor combo and I need to know what temperature I'm at with reference to the needle position. The only temperature chart I see is for the 50/110 on a 95-97 and being that that a 93 gauge will read slightly higher than a 95-97 I need someone with a 93-94 to chime in. One last thing at what temperature would one stop and turn off the vehicle to prevent any damage I would take a guess at 220?

Thanks
George

[RavenTai]

I could be wrong but as far as i know only the standard mod (110/50) has had any thorough testing for temperature.

[RavenTai]

Originally Posted by Cruiserdrew

Once done, it totally changes the way you look at your temp gauge. It is helpful to calibrate with a scan gauge, but once done it's amazingly repeatable.

you are right and I should clarify, I have never seen a particular gauge not show repeatability compared to itself, but of the three I have put through testing (one 96. one 97 one a 93) there was a difference of a few degrees,

Weather there is a difference between years or is there just a variation from gauge to gauge is unknown.

[JerseyCruiser]

Originally Posted by RavenTai

I could be wrong but as far as i know only the standard mod (110/50) has had any thorough testing for temperature.

You are correct. Did you ever find out what the difference is between the 93-94/ 95-97 gauges? Some in this thread said the 93-94 runs a bit hotter just wondering if its just the engine setup or is the gauge slightly different in its readings.

George

[RavenTai]

I found a difference between one particular 93 vs a 96 and a 97, this was the gauge isolated by itself in the test bed not attached to a vehicle, it is worth noting this particular 93 gauge did make a trip from BC Canada to Georgia back to BC and back to GA again before testing.

I cannot say weather this few degree difference was just that particular gauge or was it a trend that would apply to all 93/94 gauges. was it my error is setting up the test bed? with a sampling of just one none of this can be answered. it is just a few degree's for the most part not a problem.

[80t0ylc]

After putting some miles on my rig with this mod it becomes very apparent how effective the temp gauge is now in monitoring how hard engine is working & cooling system health. With original gauge design, I was blissfully naive about how stable my engine temps were. I highly recommend this mod to all 80 owners with the 1FZ-FE engine. I can imagine how valuable it is for this engine with a SC setup. With the aluminum head on the cast iron block, I consider it indispensable for getting as much mileage as possible out of your HG, original or not. Just my .02 - YMMV

[Cruiserdrew]

I have, I think 4 extra sets of these resistors from Moser. These are the high quality ones recommended for this mod. If you would like a set to do yours (not because you're a hoarder) send me your address and I'll send you a set, at least until they are gone.

This is a great mod and the 80 should have come like this from the factory, though I understand why it didn't!


Edit:
6/28/2009 My supply is now all gone. I hope the recipeints enjoy this great mod as much as I have.

[maniacv]

I have one extra set if anyone needs them.

[malottki]

I would love a set of the resistors. Just did some hauling from tennessee and I would stare at my temp gauge hopping it wasn't getting to hot. Email me at malott_ki@hotmail.com.

Thanks.

[CanyonRig]

I was cruising down the CA-91 from Riverside to Orange in my 94 80 when the temp gauge needle went past the red zone, and remained pegged above the red zone. I exited the CA-91 as soon as possible and pulled over to safe spot and inspected. Everything seems to be intact, with no signs of leakage or smoke. The expansion tank was empty (as I filled it up 2600 miles ago from IL-CA XC trip), but the radiator was full. I was able to get home, refilled the expansion tank , and waited until the following morning to test run the engine from dead cold. The temp gauge needle is still pegged above the red zone, and when the ignition is off the needle points all the way down still.

Will this temp gauge mod fix the problem or do I need to get a new gauge assembly all together? Any other advice would be appreciated. Thanks...

[vkfzj80]

did the temp gauge mod today, went for a quick drive 10-15 min and the needle was about centered, we'll see how things look on the longer drives,

thanks to those that have put this mod together and created very easy to follow docs.

[RavenTai]

Originally Posted by CanyonRig

I was cruising down the CA-91 from Riverside to Orange in my 94 80 when the temp gauge needle went past the red zone, and remained pegged above the red zone. I exited the CA-91 as soon as possible and pulled over to safe spot and inspected. Everything seems to be intact, with no signs of leakage or smoke. The expansion tank was empty (as I filled it up 2600 miles ago from IL-CA XC trip), but the radiator was full. I was able to get home, refilled the expansion tank , and waited until the following morning to test run the engine from dead cold. The temp gauge needle is still pegged above the red zone, and when the ignition is off the needle points all the way down still.

Will this temp gauge mod fix the problem or do I need to get a new gauge assembly all together? Any other advice would be appreciated. Thanks...

sorry for the delay, I have been out of town

It is possible that the mod could fix your gauge if for instance if one of the two components we replace with the mod has a broken lead, but it is more likely that you have a short to ground in the wire leading from the sensor to the gauge or a short in the sensor itself, I believe that wire is in the bundle that runs near the EGR pipe, that bundle often has issues due to excessive heat,


I would pull the cluster and check the resistance of the circuit to ground at the cluster plug, see the development thread (link in first post of this thread) for charts showing expected resistance vs temperature. you could also do the mod to the gauge while it is out.

[thespruce]

Hi all - I have an 86 4runner, with a 2lII-T diesel swapped in. Does anyone know offhand if this mod will work with my gauge? The temp sender unit is wired into the stock gauge of the 4Runner, which was originally a gasser engine - without me pulling the dash apart to compare to the pictures, I don't know if this mod will work or not. Any help appreciated

Spruce

[Beowulf]

Spruce,
This mod was designed specifically for the temp gauge in the FZJ80 by reverse engineering the stock resistor values, the factory designed "dead" spot, and the desired new temp ranges. It is very unlikely that this mod will work for anything other than these specific gauges.

However, you can use the same process that Raven used to reverse engineer your gauge and come up with a similar mod.

-B-

[RavenTai]

I should post this here also

RavenTai,

I have an 86 4Runner with a 2LII-T swapped in. These engines are notorious for cracking heads, due largely to a slightly underpowered cooling system, and the known dead zone in the temp gauge. My 4Runner was originally a gasser, and has the original gauge cluster. Hopefully in tomorrow or in the not too distant future I'll pull my gauge out and see if it looks like yours - I know it's similar, but might not be identical. If it's not, are you able to give me the rundown on how to determine which resistors need to be added in? It would definitely be great to get that gauge working properly, Thanks

Thespruce

The first step is to see if the circuit is the same as the 80's gauge, see post #58 for a schematic,

http://forum.ih8mud.com/80-series-te...emp-gauge.html

Read that thread for the blow by blow on how we came up with the mod. long read but worth the time if you want to recreate it,

The circuit in an 80 gauge is a modified Wheatstone bridge, they used windings of the motors (inductors) in place of some of the resistors, changing the value of R1 moves the null temperature (center point of the needle) changing the value of R2 (replaces the zener) affects the range,

You will need to trace out the circuit in your 4-runners gauge to see if it matches the 80 series circuit.


Note, I would not use a R1 resistor of lower resistance than stock, circuit current is surprisingly high for PCB mounted components, dash melt down or fire could be the result if either the resistors wattage or resistance is too low.

are you using the 4 runner sender or the one from the new motor? it may not work with the later.