Sapper XJ

I have a few problems with my 87 xj. Don't know if they are all related of seperate. It's stumbling through acceleration, acts like it's going to die through idle, lost all tail lights/brake lights and emergency flashers, voltometer reads nothing, fuel gauge reads wrong info, coolant temp gauge is frozen just under 200, over heating like a SOB.

I've replaced the battery, radiator, upper and lower hoses, thermostat and housing after a full flush and I ordered the coolant temp sensor, but it still has all of the above problems.

I compression checked it (I did it in the dark with a very impatient wife so I reserve the right to be wrong and I'm gonna do it again in the morning) and I got these WACKED numbers.... From the front of the engine back, I got 20,25, less than 10 (possibly nothing), then 50 and 60 then 15. So what the heck do I do now? I mean I'm all ears on any of the above problems.

If it is the head gasket, how many other gaskets should I buy? cause I'm gonna replace them. If it's not then what do I do?

irishgunslinger1

the electrical problems arent head gasket.. id start by checking for a loose chassis ground or electrical short.
id retest the compression when u have time to do it properly, both dry and wet...from those numbers u have a dead hole or two..

is there water in the oil? have you checked for bubbling in the radiator when its cold? remove the rad cap and start the engine, is there bubbling coming from the radiator? if so its a head gasket...if the oil is milky white then its a head gasket or a cracked head...is there any external water leakage?

if u do head gaskets , best bet is to buy a complete head set.. with all the gaskets. i recomend felpro gaskets for everything..

Gee oh Dee

The tail lights and turn signals are a fuse and relay. Both are under the drivers side of the dash.

The stumbling and misfire could be TPS or IAC.

The overheating could be a bad water pump or failing fan clutch.

I hope you have the Renix closed loop cooling system burped right. Its not like the traditional open loop style that most are familiar with.

Sapper XJ

The oil looks clean, there is no coolant in any of the plug holes and no white smoke from the exhaust, all of which I thought were signs of a cracked head or head gasket. On my 87 there is no rad cap, just the overflow bottle and the only leak that I see is when it overheats and boils back into the bottle which dumps it everywhere.

When putting it back together this last time I pulled each hose, starting from the bottom I filled each hose with coolant until it was coming out the other openings. I don't see how there could still be bubbles in the lines.

The water pump is new. I've replaced everything in the cooling system (I think) except the overflow bottle and heater core.

As far as the electrical, I've replaced the fuses under the driverside kick panel. It pops the fuse as soon as I turn on the head lights. I'm horrible with electrical so that's as far as I got other than checking the bulbs themselves.

I'm not sure what the IAC but I'm guessing that the TPS is the throttle position sensor? How do I check if that's bad other than replacing. I was reading on here last night and thought if might be the Crankshaft Position Sensor? Any idea on that?

I am very wet behind the ears on all of this so forgive my ignorance and please be patient. I need all the help I can get cause I'm about to give up.

Gee oh Dee

Is it overheating at idle or while moving?

Sapper XJ

It seems to do fine cold at idle, but after driving a mile to the parts store not going above 25mpg I was boiling over the bottle. Once it's hot, if I don't have it in gear (manual) or giving it a little gas it dies. That's why I was thinking the overheating and acceleration/stumbling problems might be related?

Gee oh Dee

And you replaced the fan clutch?

Sapper XJ

no the fan clutch, fan shroud (it broke coming off) and heater core are the only parts of the cooling system I know about that I haven't replaced but it still has it's electric fan. Is that not enough? I'm in oregon so it really isn't that hot.

Gee oh Dee

If you have both a belt controlled fan and an e fan then the e fan is for AC. The main fain is the clutched fan, and if its not working you aren't getting the full effect. Try and spin the fan when the motor is col, then when the motor is at running temp. There should be resistance when warm. If not, then the clutch is bad.

Sapper XJ

Well I can hear the drag on the engine when it kicks on and it does spin when the engine isn't on but it's not free moving. There is some resistance to it.

I just rechecked the compression and got close to the same numbers I did last night. From the front of the engine I got 36, 25, 0, 50, 58,20. So that means the head gasket is the next thing right? But why am I getting such low compression on the rest of them?