90 xj no power to ignition

I have been a longtime lurker and just signed up. I recently purchased a 90 xj 4.0 5speed 4x4 that was not running on the hopes that it may have been the crankshaft sensor or something easy that someone not mechanically inclined may not have been able to figure out.
Yesterday I did electrical diagnosing for about an hour and a half. Not knowing what should have power though puts me at a disadvantage. I have ordered a Haynes manual, an it should be here in a couple days.
I have power to the starter and I can manipulate it with a trigger wire to the hot side of the battery. Turns over fine.
Inside the cab, with the insertion of the key there is the buzz. That is the extent of how much the key works.
Turning the key does nothing. No gauges, warning lights etc and does not turn the engine when fully turned.
I traced the power from the battery to what looks like some distribution relay right next to the battery, to the fuse block and I have power. I do not have power in the large wires that are going to the ignition switch. I believe there is a large red,yellow, orange and brown. Should these be hot? Where do they go? I have tried to trace but I have discoloration at the fuse block. Where the wire looks brown instead of red yellow or orange.
Any help is appreciated.
Thanks
Seth

The '90 had a couple of "fusible links" coming off the battery. They look like a ball integrated into the wire. If one of those blows, it would explain the no power situation. Easiest way to check is to set your meter for "ohms" and one at a time, place the leads on each end of each of these wires. Each should peg your meter and if they don't, you have found the culprit. You can pick up replacements at a junkyard, some just patch it with regular wire (not a great idea since they are there to protect you) and some buy a replacement "inline fuse" to graft in place.

HTH
Todd

I found the biggest part of my problems.
Thank you for the fusible link idea. I had checked all of them yesterday and they were good.
I found one wire red 12awg on the engine side of the firewall harness that had power but on the inside it did not. Jumped it and was able to crank the engine from the key. I pulled it apart and found that that wire had corroded and broken.
Also when I took apart the harness it is filled with a molasses like material. Is this normal?

So after soldering a small length of jumper wire to the terminal, I reconnected the red wire and I am able to turn on the ignition and crank the engine with the key.

The fuel pump is not activating. I tried jumping 30 to 87 on the 4 relays. On 1 and 4 there is no hot at the time the ignition is on. On 2 it has power but seems to do nothing when jumped. 3 opens the egr valve when jumped.

I have taken the schraeder valve out of the fuel pressure release. It had vapor pressure when I first checked it. No liquid.

Not sure if I mentioned this vehicle was parked for 8 years.

Should I try and thump the fuel pump before the tank to test it?

Where should I test for power to the fuel pump? At the fuel pump?
What color wire is hot?
Thanks
Seth

Btw I got it running by putting a gas soaked rag to the intake tube. It purrs.

Test/replace your CKP aka crank position sensor. Disco the connector and connect it back and try as well. Fuel pump harness is driver side inner frame rail back towards the tank. Disco, check for corrosion, clean, re connect. Driver side inner fenderwell underhood, near the EGR vac solenoid is the fuel pump ballast resistor. Has 2 wires, one of them is orange I believe. Jumper this connection and see if the issue persists also.

And aside from all of this, look up Cruiser's Renix tips and go through them.

X2 on that ballast resistor. If it doesn't start after jumping this resistor (it simply reduces the power to the fuel pump during initial startup) I would have someone turn the key on while I crawled close to the fuel pump to see if it is spinning.

Probably not related but the big problem I found with my '90 XJ was that the fuel line between the pump and the exit port (inside the tank) had slipped loose. It would pump a bit of fuel but could never get up to pressure. After reinstalling it with a clamp, it has run perfectly. Like yours, it had sat for a number of years so my guess is that the tank dried out and the lack of moisture allowed the hose to slip.

BTW, I have never seen a "molasses" type fluid seeping from any connections.

If you got it running, it's not likely the CPS.

HTH
Todd

Johnnie Walker said:

Test/replace your CKP aka crank position sensor. Disco the connector and connect it back and try as well. Fuel pump harness is driver side inner frame rail back towards the tank. Disco, check for corrosion, clean, re connect. Driver side inner fenderwell underhood, near the EGR vac solenoid is the fuel pump ballast resistor. Has 2 wires, one of them is orange I believe. Jumper this connection and see if the issue persists also.

And aside from all of this, look up Cruiser's Renix tips and go through them.

Click to expand...

I pulled the fuel pump and it looks like a marshmallow that was left over the campfire too long. All of the rubbers are in a semi gooey state.
I ordered a spectra premium fuel pump assembly (the whole thing, the old one is really that bad) after reading nothing but bad about airtex.

Even the grommets for the rollover valves were gooey on the tank side

Hopefully I change the pump and filter out and have a running car.
Thanks again for all of the help.

the top orange/red wires in the firewall connector always burn out the pins.

It's best to simply bypass the connector for those. Use some 10G wire and do it proper, they will be a problem again. Check your ignition switch too. The brown wire tends to burn up there.

also, pull the fuse block and check it's backside for ugly corrosion.
if the clutch master has ever leaked (and it probably has) then the brake fluid does real bad stuff to the back of the fuseblock.
hopefully whoever replaced the master in the past took the time to pull the fuseblock and clean it all up.

Good call on buying the whole assembly. I had originally intended to change out my fuel pump but soon realized that every pump was a different size. I had a bosch on mine and none of the pumps available from the local parts stores would physically connect to the existing bracket. I eventually gave up, reinstalled the old bosch and simply added a new filter sock. If I had simply bought the whole assembly, it would have been much easier. What a PITA!

Hoodie ninja said:

I pulled the fuel pump and it looks like a marshmallow that was left over the campfire too long. All of the rubbers are in a semi gooey state.
I ordered a spectra premium fuel pump assembly (the whole thing, the old one is really that bad) after reading nothing but bad about airtex.

Even the grommets for the rollover valves were gooey on the tank side

Hopefully I change the pump and filter out and have a running car.
Thanks again for all of the help.

Click to expand...

make sure to check the resistance of the sender before you install it.

the chrysler gauge is backwards from the renix gauge.

Ok. Installed the new fuel pump and filter. Fuel pump circuit was working. Primed and fired right up.

Now I just need need to adjust the clutch.

I drove it around and the power feels great. 4x works.

I will also do all the tune up stuff. Plugs wires etc.
the electrodes are almost burnt off. Probably original?

How easy are these things at passing ca smog?

Thanks for the tip on checking the fuel sender, it was the same as the one I bought.

CA is pretty rigid. On my '90 I passed with flying colors in Texas but checked my results against CA and found that I would have passed there too. Here are some of the things I did prior to the test:

1) removed the head and cleaned the carbon deposits off. I also changed the valve seals. Total cost: ~$170 (including the valve spring compressor - $55, head gasket set - $47.99 and new head bolts - $65).
2) replaced the fuel injectors - $60
3) replaced the EGR valve - $80
4) cleaned out the throttle body and the intake - carb cleaner
4) changed the O2 sensor - $50
5) changed the plugs/cap/rotor/wires - $110

As I review this list, I probably didn't need to do the "backyard rebuild" on the the head (but glad I did). The fuel injectors were pretty gummed up and needed to be cleaned (lots of video's on youtube on how to do this yourself) or replaced (for $60 on ebay replacement was easiest for me). My O2 sensor was shot (broken lead). EGR may have been ok but was easier to change out while I had the top end apart. Cleaning the throttle body and intake was a good idea (inexpensive and a good practice regardless). Tune up was long overdue.

For a "quick fix" many people simply change the plugs/rotor and run a bottle of seafoam through it.

HTH
Todd