• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

So then jeep runs...but has no power

Peacefrog53

Peacefrog53

NAXJA Forum User
Location
Lake Forest, CA
After Ted and I fixed that stupid grounding issue, I have taken the jeep out twice. Both times, the jeep will go...but when you hit the gas a little more than 1/4 it sputters, i see the battery voltage drop significantly, and the jeep almost dies. If i back of the gas it will run fine. I can get it up to speed...eventualy...but wtf. I just checked all of the sensors, and the only ify one is the O2. But I have had that disconnected since i bought the jeep, and it ran fine before. Did my jeep decide it wants it's o2 sensor back or what???

Any advice fellas? Starts fine. Idles a little funky, but same as always

O. And my cat conv. is completely empty. All the crap blew out into my last muffler..which in turn dislodged it and I saw $250 worth of mufler taco against my rear axle. Well I saw it afterwards.
 
Re: So then jeep runs...but has no balls

Usually a problem under load is either back pressure (too much) or fuel pressure or volume (too little). Check those, and yes, your jeep does want a functional O2 sensor, it told me so.
 
Re: So then jeep runs...but has no balls

Check the TPS and make sure it is installed so that it turns when the throttle shaft is rotated.
 
Re: So then jeep runs...but has no balls

Ok. Fuel pressure and o2. Fuel pressure should be good. Brand new pump and filter. Possibly pressure reg.? Hmm....

And why all the sudden the o2 sensor is a problem? I thought I had just figured out the whole jeep riddle. :banghead:

TPS is installed correctly and reading about 0.81 volts. Voltage fluctuates when the TPS ismoved too. So I can only assume it is functioning fine.
 
Re: So then jeep runs...but has no balls

Might wanna change the TPS anyway. I had an xj that did the EXACT same thing. I checked the TPS multiple times and it checked out fine. I changed it anyway cause I ran out of things to check and the jeep was good again. It was $27 on rockauto.com
 
Re: So then jeep runs...but has no balls

ok replaced TPS. Changed injectors, rechecked all sensors. not o2.

And some SEAFOAM.. Time to smoke out the neighborhood.

:greensmok
 
Re: So then jeep runs...but has no balls

So it idles awesome now. 1/4 gas still is good... but I still have sputtering when i hit it. Could it be plug wires??? I just replaced all the plugs yesterday, so thats not it. Dist. cap plug wires and rotor are about 1 year old.

Alternator?? It seems to be electrical. Fuel is good. No vacuum leaks...

EErrgg.. I don't have any hair to pull out...damn it..
 
Last edited:
Re: So then jeep runs...but has no balls

This same thing happened to me, I ONLY changed my plugs and not my cap and rotor and it ran as you explained. I changed the cap and rotor and problem solved...
 
Re: So then jeep runs...but has no balls

Many times when you change the plugs, you flex the old hard wires and they crack inside. I am fighting the same thing and will be replacing my wires tomorrow.
 
Are you sure the grounding issue is fixed? If it ran fine b4 the grounding was fixed, and now runs like crap, maybe it wasnt full repaired. That why its half working. Well 1/4 working.

Sent from my SGH-T959 using Tapatalk
 
Re: So then jeep runs...but has no balls

Unplug the TPS and take it for a drive. Renix rigs will drive just fine without them. If you have an AW4 only unplug the three connector side, not the four connector side.
 
Re: So then jeep runs...but has no balls

when mine did this it was the hose from the pump to the sending unit flange inside the tank, it had come off just enough that it would pump gas and idle fine but sputter and run like crap any time i touched the pedal
 
Re: So then jeep runs...but has no balls

After my engine swap it did this to me and it was the O2 sensor, unplugged or plugged in it did not matter. I replaced it and it runs great.
 
Re: So then jeep runs...but has no balls

If this is a new problem that started after you did some work, you really need to go back and check what you did.

Also, "should be good" is not the same as "checked and is within specs" Check fuel pressure AND volume.
 
Re: So then jeep runs...but has no balls

i agree with John, mine showed good pressure at the rail both after it primed but before start and at idle, but touch the throttle and it dropped to almost nothing. did you put a gauge on it?
 
Re: So then jeep runs...but has no balls

Ok. I guess i'll have to get the test kit. I just don't see how the fuel could be the problem. I'm trying to avoid taking that damn fuel pump unit out again. Such a PITA to get back on.


And there is one wire that I noticed is a little fried. Still copper and conductive, but the coating is fried. It is in the wire loom going across the front of the jeep. I need to replace it.

And the only thing that we did was replace the wire going from the ballast to the pump. The old wire is still there, just cut off on both ends. I plan to rewire a lot of the truck when I finish my engine. I don't need or want half of those wires in there.

I'll keep you guys posted. Thanks for your suggestions. I appreciate it. :peace:
 
Re: So then jeep runs...but has no balls

I would take a look at any wire that comes anywhere near that wire that is fried as well, all it takes is a tiny hole in the insulation to cause a short.
 
It was that damned fried wire. It ran from the starter relay to the other side of the truck....thinking into the ECU.. BUT it was only cooked half way.. So i replaced it and the truck runs great again. Even at 246,000mi, this baby purrs like a..... well it can't be kitten....it's friggin old...purrs like a jeep... :farmer:


When it starts...and can ACTUALLY run.....
 
You must log in or register to reply here.

Similar threads

O
1984 Jeep xj-no restart
Replies
6
Views
3K
Forest
F
B
Jeep xj surging
Replies
11
Views
433
Bmfinney
B
T
Oil In AIr Filter/Not Passing CA Smog
2
Replies
22
Views
4K
cruiser54
C
P
2K IDLE - Odd Shifting - TPS? (I know.. I know)
Replies
3
Views
2K
Unclewolverine
U
G
No Start After Welding, Fuel Gauge Not Working. I'm seriously confused.
Replies
9
Views
2K
tjmotter
tjmotter
Back
Top