Viper light surging/bucking at low rpm??

[Kirkinsb]

My 2003 with 21,000 miles is surging "lightly"at low rpm about 1500-2000 rpm in 2nd and 3rd gear with light throttle. You can definitely feel it. Seems to be getting worse. You can feel it bucking back and forth more and more and now you can even see the tach needle move up and down.

Any ideas where to look? Just changed plugs and wires because it was time...but that did not solve it. Ideas? Anyone experience this? Car is basically stock with no CATS. has a ROE tune. Cannot recall if it had the surging/bucking before the tune. But since it seems to be getting worse, I would not think it could be the tune. Cam or Crank or some type of sensor. What about a clogged fuel injector? My tech wants to do a full diagnosis hooking it up to his computer machine to look it all over since he noticed it surging/bucking at low rpm with light throttle last time it was in.

Thanks for any help.

 

[viper04blk]

every car with a longitudinally mounted motor mated to a standard transmission has done this for me...including my viper I recently purchased. Would you say this scenario is true for you...

Your going residential speed in 1st gear (or even 2nd gear) and you take your foot off the gas (with hopes of coasting) and the car bucks and bucks and bucks until you give it gas and start accelerating again? It feels like if you are not accelerating your feeling this buck and low rpm in a low gear (1st or 2nd)?

 

[Kirkinsb]

This is with constant and steady throttle. Not accelerating or decelerating.

But, yes I have experienced what you describe...but my issue is with a steady light throttle.

 

[viper04blk]

oh....

I once had such problem with a 80's z28. And the problem was a sparkplug wire. I have not played the viper enough to give you accurate advice.

 

[viper04blk]

try putting a timing light on each spark plug wire. You can tell if the sparkplug wire is messing up by the lights that flash

 

[SANCHOBA]

On my 04 ram srt-10 I had the same problem, it was the TPS ( throttle position sensor) a cheap and easy fix, ( I hope)

 

[Kirkinsb]

SANCHOBA...I ordered a new OEM Throttle Position Sensor. It should be here in a few days! Thanks.

 

[Kirkinsb]

New OEM Mopar TPS sensor seemed to do the trick.

 

[ViperJeff]

Good to read

 

[NI-KA]

There are many threads on this. Try doing a search.

 

[LETZROC]

GOD sounds just like my 06I have been fighting this for 2 years now and when accelerating never an issue then start cruising and you can feel it start in your seat(feel it in your ass I say)I've been to the dealer and ****ed around and yes we got it and back it came, 02 sensor, new computer, wire harness, so I starting looking at my injectors, car sat for a long time still only have 6500 on it, but I also have intake, hiflo cats and a ROE TUNE. Sean at Roe kept saying it could be this or this or this,so what I did (actually my 15 yr old did it and suprised the hell out of me)pulled all injectors and sent them to a injector rebuild guy, this guy was MR. INJECTOR up here in Michigan,on Ebay, $20 bucks each, replaced everything checked them cleaned them, found cheaper guys after the fact but Iwas ready to buy new for almost $600 so what the hell. He called me and said they were beautiful and found nothing wrong with them, they were so nice he could sell them, so NOW what I was pissed.they came back son put them in, went to "stock" tune and guess what GONE!!!!!!!, woodward dream cruise, in traffic, on highway, perfect. it did feel alittle sluggish in the throttle because I was used to the tune but ok, now I fuc-ed up, I did 2 things so which one fixed it?? well today I put back in the ROE tune, pulled out of my drive way and it bucked once but was it because I just started and it was cold??don't know Drove it for 45 min and it ran Great.My guess is that these motors are so touchy that probably I had a slight issue with an injector and that threw the car into a loop, because when my had the issue it sounded like the whole right side of the motor was not firing, tried to rev out of it, bog off the light too usually would start after 15 min or so. hopefully it is the same thing,IF it starts again I think the tune would be the issue, especially since we both have a ROE tune but as of right now she is running good. Also Buy marine stable(blue) and put it in every tank 1 oz for 5 gal to store or 1 oz to 10 gal. during driving season, will eliminate all varnish issues, no more red stable. its like $20 for a quart bottle. preventative maintanance

Frank