Any Ideas on what could cause this???

[got one]

Environment:
Air Temp: 78.5 F
Humidity: 31%
Altitude: 410ft
Vaper Pressure: .3 in-HG
Absolute Pressure: 29.5 in-Hg

Dyno#1 was a wash...due to an error. But as you can see...I should have more HP/TQ...AND my A/F ratio looks way off...
Mod List:
1. Recent head gasket replacment (no performance mods done)
2. Chromally Flywheel
3. TNT Headers, RT hi-flow cats, Dynomax muffllers, 3inch exhaust
4. 3.55 Gears
5. Smooth Tubes
6. K&N Filters
7. MSD plugs and wires
8. everything else is drivetrain wise is pretty much stock

But here is Dyno Run #2

And Dyno Run #3

http://gallery.viperclub.org/showphoto.php/photo/49720/cat/500/ppuser/23731

Thanks all!!!

 

[got one]

Any idea on how I can make those images larger so folks can actually read them?

Thanks,

 

[jasontiff]

Email 'em to my Hotmail account and I'll see what I can do with my FTP server.

 

[jasontiff]

Here go:

You must be registered for see images

You must be registered for see images

 

[got one]

thanks boss! you rock the cat box!

 

[triblk6spd]

Man I wish I could help. I am going thru the same !@#$ with mine down at ART as we speak. I sure hope they get a handle on it soon. Maybe a shop rag stuck in the intake? I hope you figure it out soon, I know how frustrating that can be.

 

[dave6666]

Vipair... 50hp

Fuel Line Magnet... 25hp

Intake Tornados... 25hp

For everything else, get white hood vents.

 

[Schulmann]

The AFR isn't so bad.

The torque variation at upper rpms might be related to an electrical/ignition issue.
- Check your ground points
- PCM connections
- Plugs
- Plug wires

Other than that a good mecanic will be able to verify everything around your engin.

 

[got one]

Man I wish I could help. I am going thru the same !@#$ with mine down at ART as we speak. I sure hope they get a handle on it soon. Maybe a shop rag stuck in the intake? I hope you figure it out soon, I know how frustrating that can be.

I'll keep my fingers crossed...

 

[got one]

The AFR isn't so bad.

The torque variation at upper rpms might be related to an electrical/ignition issue.
- Check your ground points
- PCM connections
- Plugs
- Plug wires

Other than that a good mecanic will be able to verify everything around your engin.

will check those tomorrow... thanks!

 

[got one]

Vipair... 50hp

Fuel Line Magnet... 25hp

Intake Tornados... 25hp

For everything else, get white hood vents.

too bad I don't have hood vents...

 

[PhilC]

It kind of looks like something mechanical perhaps in the valve train My brother had something similar but his started at around 4000 rpms. His motor had been rebuilt by a bumbling ***** in Illinois (not mentioning any names) so it's not likely relevant. The exact cause would be hard to pin down because he ended up rebuilding everything and then retuning.Good luck.

 

[JonB]

Schulmann[/COLOR];2630322]The AFR isn't so bad.

The torque variation at upper rpms might be related to an electrical/ignition issue.
- Check your ground points
- PCM connections
- Plugs
- Plug wires .

My bet indeed........just this AM yet another customer emailed me that his runability woes were solved by plug wires, even tho tests and mileage would say otherwise.

Plug Wire Age Matters

 

[got one]

My bet indeed........just this AM yet another customer emailed me that his runability woes were solved by plug wires, even tho tests and mileage would say otherwise.

Plug Wire Age Matters

Hoping so...that would be an aweful easy, quick and cheap fix...

 

[Jack B]

What you are viewing is not the whole story, your plots are using a smoothing of 5. That alone is hiding the the true curve/perormance. You should get the actual files and re-plot them with zero smoothing, then, we will have a better picture to assess.

Another tip, if they are using the Dynojet brand of a/f logger, there is a built-in (not removable) smoothing that injects a large degree of error. It typically shows a full point leaner, but, that is dependent on how the pre-wot ramp-up is performed. That is probably why the a/f does not show the same issues that the power plot is demonstrating.

The problem is probably some where in the ignition or ground system as has already been stated. It probably is not mechanical since it also happens at a lower rpm, although somewhat less severe.

 

[got one]

Thanks Jack B...I have the original files...I"ll take out the smoothing and see what it looks like.

Also, chatted with Tator this weekend...ordered a new set of O2 sensors...since the originals are in there, it might be the culpret, not to mention that at the very least would be a good time to replace them anyway...i'll let you guys know if that fixes the problem...REALLY HOPE SO.

 

[got one]

O2 Sensors didn't work...taking into shop...car has been down for over a month and the driving weather has been perfect...time to let the pros check it out and hook it up to a computer and such...

 

[jasontiff]

I have an OBDI scanner if you wanna play Viper Tech at my house...I even bought a "Viper Specialist" patch on Ebay!

I wish I was joking...sadly I'm not.

 

[TexasPettey]

So, it's still there? That's not good. Want to try plugs and wires?

 

[Phil Lee 94 red RT]

You guys stay up way too late. How did the brakes and rotors work?

 

[got one]

You guys stay up way too late. How did the brakes and rotors work?

Brakes and rotors worked fine...actually stops 100% better than before...WOW!

MIGHT try and do plugs and wires tonight...not sure how to troubleshoot wires though...or plugs outside of just replacing them all...

 

[got one]

I have an OBDI scanner if you wanna play Viper Tech at my house...I even bought a "Viper Specialist" patch on Ebay!

I wish I was joking...sadly I'm not.

I have that same patch...too funny.

Ya, not even sure how this scanner would help in this case...perhaps....is the device portable by chance?

 

[Jack B]

I have that same patch...too funny.

Ya, not even sure how this scanner would help in this case...perhaps....is the device portable by chance?

With the right scanner you can look at injector pulse width. Take a wot third gear road pull and see what happens to the injectors. That way you can at least rule them out and start concentrating on the ignition.

What seems interesting is the fact that the miss does not seem to influence the a/f. Typically that type of miss will drive the a/f lean. Very definitely a bad plug or wire would show as a lean spike on the a/f. One problem you have is the built-in smoothing of the Dynojet a/f sensor/software, that makes it hard to seen a/f deviations.

 

[99 R/T 10]

With the right scanner you can look at injector pulse width. Take a wot third gear road pull and see what happens to the injectors. That way you can at least rule them out and start concentrating on the ignition.

What seems interesting is the fact that the miss does not seem to influence the a/f. Typically that type of miss will drive the a/f lean. Very definitely a bad plug or wire would show as a lean spike on the a/f. One problem you have is the built-in smoothing of the Dynojet a/f sensor/software, that makes it hard to seen a/f deviations.

Jack,
you need to set aside some more time in your life to hang out here more and give input. Try to show more than once every other week.................

 

[Big Mac]

I have a good scanner too, not sure what it will show on your 94. Most of the time you can't see damage on a plug or a wire so swap them all out.

Where did you dyno?

 

[jasontiff]

I talked to Ryan today and I believe he chased down the problem. He swapped plugs and wires over the weekend and voila...problem solved.

 

[viper spray]

BINGO!!
...................................

 

[got one]

Yup...had over 30k on the plugs and wires...upgraded to AB's wires. Man the car woke up after swapping out the wires! Taking to dyno next week to see how it does.

 

[Malu59RT]

I wonder when JonB will view this thread

 

[got one]

oh cmon...just plugs and wires...from a vendor here to!