Gauges

[Dakom]

Hey guys I am new to jeeps and the forum but I just traded my dirtbike for a 88 xj 4WD 5 speed 4 door with 3-4 inch lift (i think its 3) and none of the gauges work they do how ever light up when i turn the head lights on but still no readings I am probly going with aftermarket sunpro gauges take a look tell me what you think I traded a 2007 baja x250 that was wrecked the bike was only 1000 bucks new from pep boys and i bought it from the owner for 300 I think I got the better part of the deal!

http://i1269.photobucket.com/albums/jj582/Dakom20/Jeep/IMG_0284.jpg

http://i1269.photobucket.com/albums/jj582/Dakom20/Jeep/IMG_0290.jpg

http://i1269.photobucket.com/albums/jj582/Dakom20/Jeep/IMG_0278.jpg

[4.3LXJ]

We have a member with the same problem. There are two positive wires that feed power to the right and left side of the gauge cluster. If they don't have power, none of the gauges will work. So first thing, check the instrument fuse and see if it is good. Of course if you are dead set on aftermarket gauges, go for it.

[Dakom]

yeah i tried that every thing seems good but i have already ran my tach, oil, and water temp

[bigjim350]

If you ran a mech water temp, where did you install the temp probe? Can't find a place on mine.

[Dakom]

well umm I dont know the name of it but its at the front of the motor on top there is a port with a sensor i removed the sensor and put the new mech probe in I will take a pic and post

[Dakom]

Its located right where the blue sealant is
http://i1269.photobucket.com/albums/jj582/Dakom20/Jeep/photo7.jpg

http://i1269.photobucket.com/albums/jj582/Dakom20/Jeep/photo13.jpg

http://i1269.photobucket.com/albums/jj582/Dakom20/Jeep/photo14.jpg

[4.3LXJ]

That is a great place for a temp sensor. However your coolant temp sensor for the engine control module needs to be there. The best you could do there is some type of a T fitting or tap a new hole there.

[Carves]

Personally .... I'd fit an inline sensor mount in the heater hose or the rad hose.

.... only coz .... with all the XJs issues of coolant levels and stuff - the t-junction raises the sensors/senders up and out of the coolant flow path ... and for correct temp readings - the things need to be, constantly, immersed in the liquid.

[Dakom]

well took it trail riding and it did just the same as it did with the sensor hooked up there was no diffrence so i will leave it like it is until i notice somthing it ran about 160-190 thats with ridin in mud in 4Low

[bigjim350]

That sensor tells the comp when to turn on the electric fan, also with it unhooked it will make it run rich and get much worse gas mileage, course if its just a wheeler that shouldnt be a problem

[bigbuk29]

That sensor tells the comp when to turn on the electric fan, also with it unhooked it will make it run rich and get much worse gas mileage, course if its just a wheeler that shouldnt be a problem

Ok, got my attention here, I love to learn new stuff. How does that make it run rich, especially on an older xj. I always was under the impression that the o2 sensors were what the computer used to adj. rich or leaner conditions, and I'm pretty sure all that goes away at WOT:confused:

[bigjim350]

If the ECM doesnt have a temp sensor to tell it that the engine is at operating temp, the comp will stay in open loop mode, which will make it run richer.

[Carves]

Ok, got my attention here, I love to learn new stuff. How does that make it run rich, especially on an older xj. I always was under the impression that the o2 sensors were what the computer used to adj. rich or leaner conditions, and I'm pretty sure all that goes away at WOT:confused:


The computer and the EFI throttle body have to perform the same function as an old school carby and choke set up ... i.e. meter the fuel and airflow.

The computer has a bunch of preset injector settings in regard to how much fuel flow is allowed.

Basically ..... When the engine is cold ... the max number of injection pulses are applied ... and as the engine/coolant temp gets warmer - then the amount of injection/pulses get less/slow - at various, predetermined, pre-programmed, temp settings.

Once the temp is up to about 160*/170* ... the XJs computer accepts, that temp, as being a minimum ... "warmed", operating temp ...

... and remember ... the computer doesnt set the injector pulses according to the coolant temp ... but rather - the temp the coolant sensor is recording ... which is why the sensor should be checked for correct operation on a regular basis.

Inputs from lots of other engine sensors also make ajustments to the injector pulses.


Open and Closed Loop ... is in relation to when the O2 sensors become operational .... which is a few minutes after start up ... and co-incidently at about 60*f/70*f coolant temp ...

See here ---> http://www.xjtalk.com/showthread.php?t=9470


4 wire O2 sensors, with built in heating elements - aren't dependant on engine/exhaust temps to operate properly - unlike early 2wire sensors.

The O2 sensors just "fine tune" the fuel settings that the computer ... is already using ... whether they be cold running or hot running settings.

Since they are an emissions add-on ... and not a "driving" enhancement feature ... the O2 sensors are bypassed in a variety of driving scenarios - like WOT, as you mentioned.

Theres quite a bit of detail in the factory workshop manuals that give an indication of how it all works ... but its not "technical", nitty griitty, how does an EFI system work, type info ... and you need to find all the info in various chapters to make any sense of it.

Dunno about renix system details ... but the corresponding info in the OBDI & OBDII manuals suggest both systems ... have the same operating parameters.

[bigbuk29]

damn way more complicated than what I wanna get involved with. If I cant fix it with a bfh, a welder, or duct tape and bailing wire, I call my brother he is vw tech and laughs at some of the things I call him for that I have been trying to figure out for days, and he pulls his laptop out and fixes in 15 mins lol But thanks for the info, gonna look it up and see if I can get to all make sense

[Dakom]

drove it 63 miles today and it ran the same as for the fans i am putting them on a seperate switch

[Dakom]

update jeep is still running great i have the aux fan wired seperate and I just got the factory gauges working today (hidden fuse) speedometeris working gas seems to be we shall find out next fill up and as for the ugly cone filter its gone put a regular factory filter and intake back on it (from a 1990 Comanche) thanx Journey can U run it with out the charcoal canister and the what ever ever its called the pipe from the valve cover to the intake not sure they were working well before due to previous owner just taped them in the cone filter