Newbie needs advice....

[BigSnake]

Hello Everyone,

I recently traded my 99 Vette for a 96 RT/10 with 38K miles. I love the Viper, however, I need some advice....

I am having an intermittant hesitation problem. I performed a search before posting this but I didn't find anything that really helps.

Problem description:

On occassion, the Viper will start having irractic idle bouncing between 500 - 1000 RPMs. When this happens, the car will begin to hesitate regardless if I am driving slowly or aggressively, usuall between 2000 - 4000 RPMs. Upon startup, the idle is high around 1000 rpms, if I turn on the air conditioner, the idle did settle down.

What I have done to correct the problem.

- I cleaned throttle bodies.
- Viper tech synchronized throttle body cables
- Viper tech replaced spark plugs and inspected wires.
- Viper tech replaced fuel filter.
- Viper tech replaced throttle position sensor.
- I removed battery and took to 2 seperate auto parts stores
that checked the battery and told me that it was fully
charged. This effectively reflashed the PCM but the problem
returned.

I am thinking that the idle air control motor should be considered and maybe the plug wires or intake manifold gasket.
Since the problem is intermittant, I was think that the plug wires and intake manifold gaskets may not be the culprits..

HELP!!!!

 

[cstegall]

Viper Wizard???...where are you?


No Flame Intended...Just Observation,
CStegall

 

[Viper Wizard]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by BigSnake:
I am thinking that the idle air control motor should be considered and maybe the plug wires or intake manifold gasket.
<HR></BLOCKQUOTE>

It could be the IAC motor? I would check the intake gaskets at Temp[hot motor]. While it's idleing, spray a little carb clean at the bottom of intake runners[manifold to heads area, all 10] and see if the idle changes. If it does = gaskets.

As for the wires, easy test spray water on them. If idle changes = wires.

What kind of mods are on your Viper?

 

[BigSnake]

Thanks for the input Viper Wizard...

I will have check the intake manifold gasket and wires today...

My mods are S&B filters, smooth tubes and I deleted the rear muffler.

I noticed yesterday that when I am trying to maintain a constant speed with throttle opened very slightly, I get the pulsing or hesitation, then when I come to a stop, the idle is erractic, bouncing between 500 - 1000 RPMs

 

[joe117]

You can look at the wires in the dark, with the engine running of course. You can also use an unlit propane torch instead of carb cleaner to find intake leaks.

 

[BigSnake]

Here is the latest...

Last night, I unhooked the battery terminal under the hood...
I reconnected it this morning and the idle was irractic and high bouncing between 500 - 100 RPMs

After about 5-10 minutes it settled down to normal idle and was at normal operating temp.

I then used WD-40 and sprayed the bottom of the intake runners near the manifold to head area.... No change in idle... the car idle was normal

After about 5 minutes or so... I sprayed water on the spark plug wires boots and again no change in idle.... the car was still nromal

after waiting another 5 minutes or so, I then used carb cleaner and again sprayed the bottom and top of the intake runners... still no change in idle... it was still normal...

The car idled for about 20 minutes after this test then began to have irractic idle but settled down back to normal after about 30 seconds.

 

[Tusc]

I just read the thread and it sounds like you ran down some good possibilities. Sounds like the dealer nipped the problem for you. I was going to suggest checking the IAT or the MAF (does the Viper have MAF or is it MAP? don't know yet, still on the learning curve with them!). Anyway, was going to suggest IAT because my C5 had the same issues over the past year. Reprogramming the PCM wasn't really the cause or solution to the problem. It was the IAT wiring itself that was bad. After going through 2 sensors (and 6 months of this idle problem) they finally decided (on my suggestion) to check the wiring itself. In the end, they replaced the whole IAT wiring from the sensor to the PCM and the problem has been alleviated.

I know how incorrect water temp readings affect the PCM programming, but unless they were WAY off I think your larger concern was the faulty IAT. Good that they noticed the temp and the battery readings, too!

I hope the problem doesn't recur. And, from one soon-to-be Corvette to Viper enthusiast to one who has taken that leap - enjoy the car!

 

[Tomer]

Congrats BigSnake!

Now that the problem is solved (keeping fingers crossed), what colour of sweeet 96 RT do you have?

Tomer

 

[BigSnake]

Problem solved... at least it has been for the past 600 miles...

The solution... The dealer reset/ or re programmed the PCM. This would be different from unhooking the battery... The dealer connected their monitoring device to my car and noticed incorrect reading for the idle air temp, battery temp, coolant temp among other things.

After the dealer reset/reprogrammed my car, it has it running like the beast that it is....

Thanks for the suggestions...

BigSnake

 

[joe117]

Good, glad you fixed it. However, if for some reason you ever want to check for intake leaks again, I don't think WD-40 is the right choice. I think some spray can carb cleaner is the product you want. I don't think WD-40 will do what you want.

 

[BigSnake]

Thanks Tomer,

The BigSnake's color is the best color for a 96 RT/10....

White with the cool blue stripe... don't you agree?

Now that the BigSnake is moving like it is suppose to, I can now really enjoy it!!!!

BigSnake