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Few problems with my new 91

Got a small yellow multimeter with the 2 probes. It has an ohms adjuster wheel and it has. off x10 x100 x1k(ohm) 500 250 50 10 (acv) 250 10 0.5 (dcma) 2.5 10 50 250 500 (dcv)

Should I carefully move the unit under my jeep. plug it in, connect my negative battery terminal then try and test it?

Also there is no rubber seal. There is the lock ring and that is it. The lock ring is a bit rusty and the top of the fuel pump is rusty. Where the ground is on it looks bad. Not sure if it is grounding properly. Still waiting on an answer about plugging it in.
 
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So I plugged the pump in and turned the key on.Then I put the black wire to the black wire and the red wire to the red wire. Wherever the arm was it read "200". The needle barely moved and landed on it.

Junkyard said 50 bucks for a sending unit/ fuel pump out of a cherokee there. May just replace it. Going to sandpaper the arm carefully and check then/
 
Please. I need answers. Today is the only day I have to get to the junkyard. I'll be screwed all week if I cannot go today. I tested both the red wire and blue wire. x1k read around 20 for both wires. and the other settings does not pick up anything.
 
Throw it back together and do without a fuel gauge... none of mine work right. One is screwed up and reads a half tank below where it should, another reads in reverse (full=empty, empty=full) and another randomly fluctuates from the correct value to 0. Just use your trip meter and fill up at 250 miles, once you get an idea what your gas mileage is, fill up at 17 gallons * gas mileage. The fuel leaking is the only problem you have to worry about to get it rolling.

Why do you think the motor was on its way out on the other one? Sounded fine from the videos you posted.
 
Yeah I guess so... my trip meter don't work remember :p I followed all the fuel lines and they look fine. Cleaning up some wires and grounds (ceramic baluster thing). I was hoping where the fuel was leaking was ruining the fuel pressure being why it wines so loud and why I may have been bucking. I'm going to try and find a rubber seal for the hole in the tank so It stops dripping.

Well. She would often lose a lot of power and almost bog out then a huge knock comes after that then it is fine. I wanted to move on. I needed too. I needed a new stock project. Now that I'm working kind of full time I can do the things I'd like now.

I think I'm going to get the fuel pump seal at the autoparts store so it will stop leaking and just throw back together I guess :\

The air line that goes right after the air box is broken off. So there is just a hole there with the vacuum line off. Is this bad?
 
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Important question. If I get a fuel pump seal and seal my gas tank with jb weld will that help the "fuel pressure". I figured since fuel escapes above 1/2 a tank that means there is outside air getting in the tank. Which would mess with the fuel pressure correct?

Also I just finished a compression test.

6-135
5-140
4-135
3-130
2-145
1-135
 
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I guess we can just close this thread. I'll see if I can get everything good by tomorrow. If I run into some major problem that I need help with. I'll post about it. Thanks for the help everybody. I'll be referencing this thread and using search a lot to find my answers and have my jeep good by tomorrow hopefully. Wish me luck :)
 
hupo224 said:
I guess we can just close this thread. I'll see if I can get everything good by tomorrow.
Click to expand...

impatient much?

first things first, JB weld has no business near your fuel tank. It won't hold up to the gasoline and will turn into a mess. Just install a new O ring around the sender unit properly and the tank leak will probably be fixed.

The fuel tank leak has nothing to do with your fuel pressure, the tank it not pressurized and it has vents already. how do you think air gets in to replace the fuel you're burning?

You can bypass the ceramic resistor on the fender, the pump will probably get noisier because the resistor was put in place to address pump noise complaints. Neither of my 87's has a ballast resistor.. It will be useful in troublshooting your bucking, if it is fuel related, it's possible that the resistor has a crack and is making intermittent contact. Make sure you use an appropriate sized wire to jump the connectors, something like 12 GA.

You need to set the range on the ohm meter to 100, that will give you the correct range to read the 0-90 ohm range on the sender. Sender has nothing to do with the fuel pump. It does not need to be connected to the harness to test the sender.

Go here and learn the basics on using a multimeter, then I can help you troubleshoot the ignition.
http://www.ladyada.net/learn/multimeter/

Watch the videos on resistance, continuity and voltage.
 
87manche said:
impatient much?

first things first, JB weld has no business near your fuel tank. It won't hold up to the gasoline and will turn into a mess. Just install a new O ring around the sender unit properly and the tank leak will probably be fixed.

The fuel tank leak has nothing to do with your fuel pressure, the tank it not pressurized and it has vents already. how do you think air gets in to replace the fuel you're burning?

You can bypass the ceramic resistor on the fender, the pump will probably get noisier because the resistor was put in place to address pump noise complaints. Neither of my 87's has a ballast resistor.. It will be useful in troublshooting your bucking, if it is fuel related, it's possible that the resistor has a crack and is making intermittent contact. Make sure you use an appropriate sized wire to jump the connectors, something like 12 GA.

You need to set the range on the ohm meter to 100, that will give you the correct range to read the 0-90 ohm range on the sender. Sender has nothing to do with the fuel pump. It does not need to be connected to the harness to test the sender.

Go here and learn the basics on using a multimeter, then I can help you troubleshoot the ignition.
http://www.ladyada.net/learn/multimeter/

Watch the videos on resistance, continuity and voltage.
Click to expand...

Thank you for this. The multimeter seems to not have a "100" under ohms. But I'll double check it.
 
200 should work as well... it will just read 0-200 ohms instead of 0-100. You'll still read the value.

Most analog meters are a 0-1x or 0-5x scale, while most digital meters are 0-2x scale (where x is some number in 10, 100, 1000, etc etc.)
 
Also I wasn't being impatient. I felt I needed to fix my threads as I was just basically adding notes on what's going on as replies. Yesterday I plugged the unit into the harness and then tried checking the ohms of the sender. Like I said it was stuck on 20. I'll check it again without it being connected. But I just have this feeling that nothing is going to show. I read about the "jb weld" fix when I was searching. Going back to the parts store to pick up the o ring/lock ring combo. Bought electric connector cleaner because I have a lot of scary corroded connections (I may have fixed my speedometer by cleaning the one plug and the 2 plugs going into the ballast resistor were scary)
 
:doh:

Test it without it connected to the harness. You were applying voltage to the meter with it set to resistance - if you had done that with an analog meter you would have burnt it out, fortunately digital meters usually protect against UHE.
 
if the connectors to the ballast resistor were all corroded you can bet that the corrosion has crept up into the ceramic. Bypass it using appropriately sized wire, 14 ga or heavier and the proper spade connectors.
This could be your hesitation issue.
if the sender is stuck at 100 then that's likely the fual gauge issue. Try gounding the fuel sender lead on the body side of the harness and seeing if the guage responds. it will go to full I think, I know that the renix gauge will go to E when grounded.
 
I had my dad watch the gauge. I used the pin wire thing out of the multimeter. I put it to the right wire on the harness then the other end to the body of the jeep. Nothing moved however. I'll bypass it tomorrow. Going to get the fuel tank in after work.

Also to make note. Last time I drove it which was saturday the hesitation got worse. I believe it was because I had much less gas in the tank as I was trying to burn fuel for when I dropped the tank. Each bump I hit in the road and I was on the gas it would stall out basically. The tachometer will read 0 and won't jump back up until I hit the gas. If not it would stall out completely. When I first got it I drove it 2 hours home with it bucking a hand full of times. (when I hit small bumps in the road cruising at 70 and sometimes when I'm just cruising on smooth road.)
 
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