which would you replace First?

So I have been reading a lot of post about problems with the 80's fuel delivery systems and I can't decide which to replace first. Here's what I have. 89 Cherokee Laredo with automatic and 4.0. Here's what happened. Driving down the hwy and the old girl starts sputtering and slowing down. she would go for a little bit and then wouldn't go over 10mph. Took it to a transmission place and it is in good condition. Took it to the local Jeep Dealer who wouldn't touch it because it was pre-OBDII. She will not go even if gunned and is a bear to just get started.

So I started reading here and found that the TPS and CPS can cause similar issues. Also a month prior to this happening a coolant line busrt and blew SH*t all over the engine bay and other threads I have read said that the IAC can have similar symtoms and are prone to be bad if they get wet and IT GOT WET!

Anyway I started last weekend to check stuff out and when I went to release the Fuel pressure from the valve there was NOTHING. So I started it up and let it get going and let it run for a half an hour. Then I shut it down and let it cool for another half an hour and checked the fuel pressure. STILL NOTHING!

So, on to the question if you could only replace one thing at a time where would you start; the Fuel pump, the CPS, the TPS, or the IAC? I am short on cash right now but can aford to replace one item with one NEW item ( only Choice for me so don't suggest junk yard for this stuff ) once every pay check. Where would you start given that all four and maybe the EGR are bad?

Thanx:tears:

Personally, i'd replace the fuel filter first. Make sure the elec connections are clean and dry...then add some dielectric grease.

Check the fuel pressure at rail, check dist cap for a crack, etc

Then maybe start replacing parts if you still need.

Sounds like a fuel delivery problem... See if someone in your area can check your fuel pressure and/or see if it holds pressure.... That's where I'd start...

Will.

Fuel filter then add a can of BG44K to the fuel to clean the injectors and carbon buildup.

The fact that the fuel pressure didn't hold points to a fuel pump, but run the BG44K before you spend time on the pump. It may have simply gotten gummed up and it will clean the check valve.

Replace the fuel filter and swap the fuel pump relay with your A/C relay.

The fuel pump relay went out on my old '88 and I almost replaced the pump, until a buddy pointed me to the relay. It took some work to figure which realy ran the pump, but I eventually got it. Can't remember which one it was though. The relays are on the pass side, forward of the coolant bottle.

GW Thanx for the tip. They are very close together and a great quick way to check to see it the pump is working first. "There's only two reason a car won't start no spark or no fuel."

:wave:

againstherwill said:

GW Thanx for the tip. They are very close together and a great quick way to check to see it the pump is working first. "There's only two reason a car won't start no spark or no fuel."

:wave:

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Or no compression - they like that stuff too.. LOL...

old_man said:

Fuel filter then add a can of BG44K to the fuel to clean the injectors and carbon buildup.

The fact that the fuel pressure didn't hold points to a fuel pump, but run the BG44K before you spend time on the pump. It may have simply gotten gummed up and it will clean the check valve.

Click to expand...

As usual, Tom has hit the nail on the head. It definitely sounds like a fuel pump problem so don't throw other parts at your Jeep. Try Tom's suggested treatment and if that doesn't work, replace the pump.
I rather suspect that you'll be doing that anyway. If the problem was just the check valve, the engine would be hard to start but not splutter on the highway. If the relay was blown, the fuel pump wouldn't work at all. If you still have the original '89 pump, it's done very well to live for 16 years so consider its replacement well overdue.

againstherwill said:

GW Thanx for the tip. They are very close together and a great quick way to check to see it the pump is working first. "There's only two reason a car won't start no spark or no fuel."

:wave:

Click to expand...

air....

Been there
Done that
Changed the fuel filter fixed it.....