45shutr

Hey everybody, I want to install a set of aftermarket gauges on my buddy's 1987 XJ. I would love to install a set of mechanical gauges, but I need to know a few things first:

1) Can I remove the electric OEM oil pressure sending unit and delete the circut to the stock oil presure gauge, or does the OEM oil pressure sending unit and pressure gauge circut send information to somewhere else like the computer for instance?

2) Is there anywhere in the block that I can install the mechanical sending unit for the aftermarket temp gauge? I am pretty sure that the hole for the OEM electric sending unit that is used by the stock temp gauge is too small. Any ideas? Anywhere else that will be big enough for the aftermarket mechanical sending unit and that will not interupt an important circut used by the ECU or something?


Thanks in advance for the input.

45shutr

Anybody?

Gee oh Dee

Man, I really wish I could help. I'm wanting to put gauges into my '87, but for what I'd want I'd be looking at doing all the gauges.

I hope someone else can give you the answers you need, I'd like to learn as well!

Hommersimpson

yes you can.....but what you really need to do is understand the wiring before you go hacking stuff up...Get wiring diagrams online... print them out of the wiring for the ecu stuf/ check engine idiot lights.. and the dash stuff.. trace them all down and see what acually runs into the computer and tells it whats going on... then go from there... but you should be able to take a dash and gut it make a new face plate and install gauges and be done with all the factor stuf... now have you priced a nice set of gauges ?
You do not want to put in cheap gauges... and just good basic ones for a whole set... speed,tach,oil, water,alt,fuel... will run you 300-500 bucks...
Temp guage wise.. id have to go look at mine.. but at very least they make a tube that goes in rad hose with a bung for temp sender..

45shutr

The temp gauge thing is what was really screwing with me. As far as doing a complete dash, I don't think I am interseted in that so much, just looking to do the basic oil and water temp. As far as finding any schmatics for the older Jeeps I have been looking around and I haven't found anything that I am really happy with, most info I come across is lacking or missing information. I guess what I will do is I will have to assume that the OEM oil pressure sending unit is in some way sending information back to the computer or something else important via the oil pressure gauge. Therefore, I will ground out the oil pressure gauge and run my own aftermarket sending unit and gauge, that is of course unless I can verify that the oil pressure circut is not sending info to anything important.

Gee oh Dee

Can't you unplug the factory unit and watch for a CEL or something?

45shutr

Acctually I did that with the oil pressure guage today and did not get a light, I am therfore confident that in an '87 XJ the oil presure sending unit only sends a signal to the guage. And even if it did send info elsewhere about the car, it wouldn't have anything to do with how the car runs, ie.. adjusting injector pulse width or anything like that. That being said and after talking to my friend who owns the car, do to the fact he wants to mount the gauges below the rearview mirror and doesn't want to spring for the money to but a steel braided line that long for the oil presure guage, we decided to go electric for now on the oil presure gauge. I am still going to install a mechanical guage for temp though. The way I see it is, one less electric guage is one less thing to worry about. Even if it is just the temp guage that is mechanical. So Gee oh Dee, to sum things up, in order to run a mechanical temp guage, you are going to have to run an in line radiator adaptor like the one seen here, http://www.summitracing.com/search/b.../?autoview=SKU , in oreder to be able to run your mechanical sending unit. As far as going mechanical on the oil presure, on an '87 XJ you are free and clear (as far as I know at this point) to disconnect the OEM sending unit in order to run your oil pressure guage line. Now on the late model XJ's and WJ's, you can disconnect the oil pressure sending unit but you are going to have to ground out the OEM oil pressure guage to fool the computer into thinking it has oil presure. Now you might be thinging that if you ground the gauge and it is pegged at 80 psi that are going to get a CEL do to high oil pressure, but that is not the case. The computer is only looking for a minimum oil pressure and nothing else, it doesn't car how much pressure it has just as long as it has pressure.

45shutr

By the way, thanks Hommer.

Gee oh Dee

Thank YOU 45shutr

dbcox

I got the 3 guages to do my 88. Electric temp, mech oil and volts. I am going to put them in the dash in place of the light s, but im going to T off the oil fitting and the water temp T so i can use some cool warning lights. The electric watewr temp is easier to use it will screw right in the block. I may try and post pics later, i really dont know how to do that

stuck like chuck

open a photobucket.com account (free). save pics to computer. once you login to photobucket theres a big a@@ green button that says "upload pics". click that. then click the pics you want to upload. once upload click the picture and you will see four link either next to it or below it. copy the one that has "img" next to it. then just past that here

45shutr

dbcox, you might run into problems with running a tee on your temp sending units, reason being is that the sending unit needs to be right in the coolant and running a tee off the block in some cases will not let the coolant come all the way to the probe of at least one of the sending units. At least that's how I understand it. If you do decide to go ahead and run your sending units on a tee write back and let us know if it worked out or not.

johns91xj

hey man i hooke up some auto meter gauge in my 91 and i know for sure you cant **** with the water temp sending or sending units (depending on the year) you wont get an accurate reading. as for the oil pressure just unplug it and run your own wire and mechanic line and it will work fine. mine does

rlevs

you can run any after market gage you just have to see what out put they are using and use the correct resistor to get the right read out

jon_89

I have an 87 with mech gauges. The water temp probe I used the newer thermostat housing. The oil press I just pulled the oil sender out and screwed in the fitting with no problems.