Of course, that is why I asked what I did, how is it possible to have a weak battery do that, I would assume that the alturnator would have more of an effect on that then the battery.

 

the alternator is a battery maintainer. Nothing more. It only engages when the PCM tells it that that battery needs to be charged. If the battery is weak, it can no longer hold correct amount of charge, so no matter how hard the alternator works the voltage will never rise above the battery's holding capacity.

In respect to the sensors, some (like the TPS) operate with a very low voltage range (0.2-4.8V in the TPS's case). They are very sensitive to the voltage input, as is the PCM. If the voltage being supplied isn't correct (too low/high), the sensor will not function correctly.


OP if the battery checks out ok, here is the testing procedure for the TPS:

TPS Failure:

Physical Symptoms:

The engine loses power and is stalling. The engine will idle, but may die as soon as you press the gas pedal. When driving, it seems as if all power is gone. Sometimes speed maxes out around 25 mph, and it feels as if the transmission is failed or isn't shifting properly, if at all. You can be going 25mph down the road at 5,000 RPM's. If you quickly jump on the gas you might be able to get the transmission to shift into second, but it won’t shift properly by itself. Shifting manually, the transmission goes through all the gears.

HOW TO TEST

You should have 5 volts going into the TPS. At idle, TPS output voltage must be greater than 200 millivolts. At wide open throttle (WOT), TPS output voltage must be less than 4.8 volts.. The best is to use an analog meter (not digital) to see if the transition from idle to WOT is smooth with no dead spots. With your meter set for volts, put the black probe on a good ground like your negative battery terminal. With the key on, engine not running, test with the red probe of your meter (install a paper clip into the back of the plug of the TPS) to see which wire has the 5 volts. One of the other wires should show .26V (or so). The other wire will be the ground and should show no voltage. Move the throttle and look for smooth meter response up to the 4.49 at WOT.

Perform the test procedure again and wiggle and/or tap on the TPS while you watch the meter. If you notice any flat spots or abrupt changes in the meter readings, replace the TPS.

 

I had a battery that was almost dead in my 71 waggy, had mojor issues with missing and sputtering, changed the battery, smoothed out.

Also..... if you have another battery..... and jumper cables..... well you can jump it with just a battery..... I used to do it all the time.

 

Didn't have a set of jumper cables or else i would have used that way.

Sigh, as far as a battery maintainer, that isn't right, yes it recharges the battery as well as run power to everything in the system. Battery voltage is 12.6v is a good batter when you start your car a good alturnator runs at 14+v. That isn't just to charge the battery.... actualy I am going to stop now, Obviously you are a Tech that works on cars for a living. Saddly, I don't think you are but I might be wrong.. I should stop this isn't worth my annoyence from desk jockeys and weekend warriors that think they know how it works in the real world. Good luck with the info here, I think this is my last post on this board.. Final thought3

"The alternator's job is to generate electrical current to replace what was used from the battery to start the vehicle, and to run all of the electrical accessories that are in use as you drive. That includes lights, A/C fan, radiator fan, electric seats, windows, radio and whatever other gadgets you have.
The alternator was NEVER intended to be a battery charger. If you forget and leave your lights on, never jump-start the vehicle and "drive it around" to build the battery back up."
Quote from a textbook.

 

It may be your battery now that I think of it the last time you tried to jump me it didn't work very well, is it throwing any codes? My bet is still the tps... I bet if you got rid of those ugly rims, lifted it, and got some tires that don't belong on a Honda it would run great

 

I'm gonna put a 3" lift on it when I get the money and a dude at the career center is gonna sell his jeep with 31's on it and I told him ill trade tires with him and pay the difference. He doesn't want to sell the jeep with the 31's on it. Imma talk to him more about it tomorrow.

 

I've had stuff like this happen, now that I actually put thought into it, the things that have been wrong were, battery, alternator, voltage regulator, and TPS.

Quick question, do you have a stick? And if it's an automatic, does it only happen when your in Overdrive? If you click it down to drive does it not happen?

 

Yes your leaky injector can be causing you problems. If you are leaking fuel out from around it then 1) all the fuel is not going in that cylinder and 2) if fuel can leak out, air can be pulled in and cause problems. Is it leaking out a lot? You might have a bad injector that is sticking open.

 

The guy with the nasty looking lowered xj?

 

Automatic with no overdrive

 

I don't understand how it could be my battery. I think its something in the fuel system

 

Have you tried downshifting when it happens?

And it could be your battery, your alternator has a voltage regulator, if your battery is fully charged it just supplies power to the engine. When your battery is not charged, it diverts power to your battery and charges it. So you can see how if your battery is dead/dying, then you will have a consistent draw on your electrical system. Eventually the draw will get bad enough to weaken your spark. Causing your engine to miss and loose power. It will also happen when your putting your engine under alot of strain, like going up a hill.

 

Idk about his jeep. All I know about is the tires. Jon knows a guy that has built a lot of jeeps and right now is working on taking a YJ and stripping it down to nothing and rebuilding it with a big block and turning it into a CJ. I'm goin with jon sometime next week maybe to see if I can get some cheap parts off him. He might sell me a 5" lift for 100 or 200.

 

Have you tried cleaning your throttle body out? im about to buy a jeep with idling problems, and talked to a jeep mechanic and he said their biggest issue is throttle bodies getting dirty. They start acting up and cause it to sputter and die and overall run crappy. He said that and also vacuum lines are also a common problem as well. Good luck!

 

ha ha, good point, I have an 86 with TBI, I've been having issues with missing lately but only when it's cold. I think I might try that, I am going to do a tuneup on it as soon as I get paid.... just started a new job, gotta love the 2 week check delay.

Since you posted the idea, what's the best way to clean the TB on a Jeep? I have an 86 and have heard that seafoam can clean too good and give you blow bye on your cylinders and a loss of compression. I guess I could just pull it off and use carb cleaner.