Throttle acting up

[larbow]

I need a little help. 

I started my truck the other day and when I went to give it some throttle the rpm jumped rapidly and stops at about 1100- 1200 rpm and won't go any higher. Let off the throttle it idles normal. So I shut the truck off and started it again and everything was back to normal. It has done that several time since then and is getting harder to get the throttle to function normally. I have had to disconnect the batteries on two occasions and restart the truck several time to get it functioning correctly. Would this be indicating a bad apps?

[dripley]

Have you checked for trouble codes? It could be several things.

Edited December 1, 2018 by dripley

[larbow]

I have not taken it to a dealer mechanic yet. I bought some piece of crap scanner for 35.00 It says that it is reading one code, but it won't display it.

[dripley]

Most auto parts places will scan if for you and some will loan the tool out for a deposit. This could be APPS or VP or ECM or wiring related. Thats why knowing any codes is important. 

 

Are you seeing any blue smoke when this happens?

[Mopar1973Man]

Need to know the error codes.

 

Also got to ask does the WAIT TO START light come on instantly with the key?

 

Then have you done an AC noise test on the alternator?

 

Is there any modified wiring on the APPS or added ground wires?

 

[larbow]

No blue smoke. Wait to start light usually comes on right away, sometimes a few seconds later. The only mods that have been done is a edge ez that was put on 10 years ago or more. I'll get the truck in and have it scanned as soon as I can. I do have a check engine light on. I have not done a AC noise check either, I don't know how to do that.

Edited December 2, 2018 by larbow

[dripley]

You need a volt meter capable of reading millivolts. Some are auto ranging and others you have to set the selector to millivolts. With the engine running place the + to the charging stud on the back of the alternator and the - on the battery terminal. you want to see .04 or less as I remember. @Mopar1973Man has a good article about but I think he hides from me. 

Edited December 2, 2018 by dripley

[Tractorman]

Set the voltmeter to display AC millivolts (not DC)

 

- John

[Marcus2000monster]

Might be your Crankshaft Position Sensor or Cam Sensor depending on your year. Mine was doing the RPM jump under load and threw a P0336. 

 Heres the article for noise testing. Super easy to do. 

[larbow]

Well just an update. I bought a obdlink lx. Put it to use last night. Showed a code. P0222. That was the only code it displayed. Throttle position sensor low voltage if I remember right.