blazer 2008

I have a 89 jeep cherokee 4.0 auto.I changed the TPS and it ran good but I didn,t adjust the TPS .Then it would be hard to start if I had a low tank of gas,aboutquarter of a tank, but would work fine if I had more gas in it,so I thought maybe was a bad fuel filter and changed it,it started ,so I shut it off and went to start it later that day it would try and try but just wouldn,t start.It seemed like I was out of gas or flooded I could smell gas under the hood but no leaks,almost like it was flooded.Would the TPS cause this.I can hear the fuel pump click on .Is my first fuel injection truck so I,m sorta at a loss

blazer 2008

Yes I put filter in right direction

firehawk618

Fuel tank level and TPS calibration have no relation to each other.

Start with the basics. Check for spark. Sounds like it has fuel from your decription.

blazer 2008

It has spark but how good I don,t really know,I had a long spark plug wire and looked thru the window when I cranked it.It,s trying but just won,t catch the spark or fuel.I don,t have a gauge yet to test the pressure in the fuel rail but gas is in there.

cruiser54

Very good chance that the "rubber" hose in the tank is split, collapsing, swelled or the like.

Here's how to adjust your TPS. Got the #8 Tip in my link below.

If I were in your shoes, I would do Tips 1,3,4, and 5.

blazer 2008

I f I disconnect the fuel filter and use a long hose into a pop bottle and turn the key on for pump to see if I,m getting fuel,will this tell me much on the condition of my pump?

Stabsthedrama

It will for sure tell you if it's working, yes - and I suppose you could get a good idea of how much pressure is coming out, but it doesn't tell you much about the state of a failing pump really, unless it has obvious low pressure or doesn't put out any gas at all, which was my case when mine failed at least.

blazer 2008

The nice thing is on a 89 it looks like I don,t have to remove the tank.If the hose is split or whatever is it something I can replace or really not worth the effort

blazer 2008

I found a pic,are you talking about the sock at the bottom of pump ?

Stabsthedrama

I think cruiser meant the tiny tube that is at about a 90 degree angle that you can see in that pic that connects to the top of the pump and out to the nipple. the thing on the bottom is the strainer. They commonly fall off and into the tank, so when you have it out and this is the case, just fish around the tank with your hand for it. It's not even 100% necessary, but it's obviously a good idea to have it on (and you can probably reuse it if you get one without a strainer)

And no, you don't need to drop the tank. The fuel pump in these is surprisingly easy to swap out. One of my favorite things about the Renixes. Screw having to drop the tank.

Make sure you use a brass drift or at least do what I did and wrap the tip of a chisel or screwdriver in duct tape (and replace the duct tape after a few whacks) when you are taking off the lock ring and putting it back on, so no boom boom.

Just match up the positive and negative terminals when swapping the pump (the symbols are on the white plastic part)

Replace the tubing as well - I reused the short 90 degree inner tank tube, but made sure to replace the fuel filter and the 2 short lines going to and from the tank (with fuel line hose)

Make sure to double hose clamp on the nipples at the tank, or they can leak (mine did, re tightened with 2 clamps and it's fine now)

DO NOT BUY AIRTEX. Go with Bosch/Carter (~$50-60 on rockauto with the strainer)

I'm not saying the fuel pump will solve your issue, just explaining the process. I would listen to cruiser and check out the tips of his that he suggested first.

cruiser54

Here. I needed to make this up anyway.

blazer 2008

Well I was hoping I had water in my gas with all the weird weather,snow then warm then rain and with the price of gas changing all the time I wasn,t putting much gas in,but no luck.I,ll see if I can find a fuel pressure gauge and see if that comfirms a bad fuel pump.The CPS wouldn,t be doing this? the CPS shuts off spark or fuel or both if I remember.I did all the cleaning of coil etc too.

Stabsthedrama

AFAIK cps is usually a completely dead or not dead type of failure, and yes it kills both spark and fuel.

Putting too little gas into the tank for an extended period of time could def ruin the fuel pump though. You should really never run these XJ's below a quarter of a tank.

Def check fuel pressure.

blazer 2008

If I take out the fuel pump I guess is a good idea to open gas cap to help vent plus use the brass punch for retaining ring as you mentioned before ?

Stabsthedrama

Ya I actually didn't even think about the gas cap when I did it, but to be fair once you have the pump out it'll be venting out that hole anyway. But yes, do that too.