Paxton issue. Looking for Help.

[GR8_ASP]

Some of you may have read an issue that has arisen with the Paxton setup. I am not 100% sure that it is Paxton related, as the issue occurs when in non-boost mode.

The issue is soon after starting the engine, anywhere from a few seconds to a few minutes, the exhaust makes popping, gargling and chirping type noises. the engine really runs rough while this occurs. It seems most noticeable coming out of the left sidepipe so I think it is related to the right bank. At idle you can hear an occasional pop (not too loud - sounds like a misfire) and an odd chirping sound. And now the weird aspect. When this occurs if you open the throttle a bit it completely clears and does not return. Sometimes this takes a moderate acceleration, not a gentle tip-in. But much less than say 1/2 throttle. And no boost is required. Once it stops there is no further symptom whatsoever.

I first suspected the spark plugs. Purchased and installed a new set of Champions gapped to 0.032 in. No change.

Next I suspected oil pullover. Removed the air cleaner and found no evidence of pullover at all. Dry as a bone (much to my surprise).

I just finished removing the intercooler and all seems well. No fluids and no obstruction.

Before I button it up again I plan on soldering the wiring connections as they were originally installed using the clip on method.

Any advice and/or guidance out there???

 

[Art 138]

Viper SRT: On page 3 of the threads you posted a suspected problem with your spark plugs, did you change them? If so you need to check your timing. As I understand the Paxton SC should not affect this type of performance at idle. Look at the colder type plug I have installed on mine on the previous thread you posted "spark plug recommendation." Did you change your stock exhaust?
if so you need to re-set the module. DLM advised me that if I changed them,the SC control module would have to be re-set.

 

[GR8_ASP]

I did indeed change the plugs which had no change whatsoever. I gapped them colder as advised, but as I indicated it had no impact.

Yes I have a free flowing exhaust.

Not sure what you mean by resetting the Split Second module. In the low rpm low load range that this occurs it should not be adjusting anything beyond the inherent 1.5 degree spark retard. Note that this condition started after more than 1000 miles of use. It was not evident at all earlier.

Vacuum seems fine (indicating to me that the valves and piston sealing are okay) though I should pay more attention to the vacuum when it occurs. Fuel pressure is absolutely constant.

I do not yet have my fuel air gauge connected, so I have no idea what is happening there. I am not sure how soon after starting the engine control goes into closed loop. It could be that open loop conditions are required (that is one thing that changes that I should look at). Not sure what would be amiss during open loop that would not be present during closed loop, but fueling could play a part if it is running abnormally rich or lean. Now that I think about it that seems like the most likely candidate. Just not sure how to evaluate or change it. Hmmm.

 

[Doug Supercharged Vipers]

May I suggest, checking the vacuum line that leads to the Split Second controller... There may be a kink or a small leak that leads from the engine to the box. Think "vacuum & pressure" during your inspection of other components.

Your "Spot-On" about soldering the wire connections. I don't recommend using the wire taps, they cause wires to split and fray.

Hi Art!
Best of Luck and hope this helps
Doug

 

[acrdakota]

Any new news on the problem? As stated check everywhere for vac leaks and small sensor plugs. Double check the plug on the IAT sensor.

If you can't track it down let us know and we'll start diagnosing things.

Oh yeah, and get the flippin wideband on it already. I'm sure your safe but that will tell you the world about whats going on inside the motor.

 

[GR8_ASP]

I know about the wideband. Got the Dynojet unit. Just have not had the time to get the boss welded on to the exhaust pipe. Then of course comes the question of where to place it. I have a 2 gauge pod already. Hmmm.

Hmm, a small vacuum leak or kink. Had not thought of that. That would pull a healthy amount of spark out and add fuel. Ah, but I have not detected a fuel pressure increase. If the SS unit detected it was in or near boost would it not also increase fuel pressure?

 

[acrdakota]

The SS controller should only increase fuel pressure when it sees over atmospheric manifold pressure. The reasoning behind checking for vac leaks is that it may be seeing a reduced vac and thus adding more fuel/timing than it should, but still with in stock pressure paramaters.

Might also check the MAP sensor.

 

[GR8_ASP]

Okay. But I do not understand how it would impact the fueling as the SS only controls the fuel pumps. It does not have any direct control over injector pulse width in the Paxton layout. As I recall the map it pulls out spark and adds the first step of fuel pressure just below atmospheric. From there the fuel pressure control unit controls the pressure I believe as the SS can only turn on the second pump as 1 step.

Not sure I mentioned above but th eplugs in general looked good (pictures were posted on another thread).

Do you mean the stock MAP sensor or the unit internal to the SS unit?

I am starting to think this is an open loop part throttle condition. And it stops as soon as it reaches closed loop conditions. Oh well, time to sleep on it. I soldered it all and buttoned it back up. Can't start it until tomorrow for fear of ...

 

[ViperGMC]

This is going to sound really strange but I had a very similar problem and the problem and solution seemed to weird to share. Your symptoms sound very similar to mine with a few exceptions. Upon starting in the morning I could here the chirp/whine/rattle, but it sounded like it was coming from the passenger side exhaust area. It would last until I got out of my driveway and started down the street and then it would stop. It seemed that once the car warmed up it away. It never did it when I started the car up in the afternoon even if it had been sitting all day, so I thought that it had to be related to something only when cold (overnight cold) but I did not know what. After starting up in the morning, while I heard the chirp/whine/rattle, I tried to determine if it was an engine rev issue or rolling chassis issue, but it seemed to be neither.

My best theory was that it was the exhaust rattling against something on the seal cover and after it heated up and expanded, it no longer made contact. It sounded good enough to take the seal panel off and tighten things up. That did not solve the noise. My engine has always run a little rough and pops when I first stat up, so it did not seem to be the engine at all. I gave up and ignored it for about 6 weeks or so, but it did every morning.

Then one morning I turned the key and I heard the chirp/whine/rattle and I had not yet started the engine. Hmmmm, I immediately got out to find the source, but it stopped. It had to be an electrical problem, fuel pump, intercooler water pump The next day the chirp/whine/rattle was a little louder so I got out, popped the hood and when I pressed on the plastic air intake plenum, I could change the tone of the noise, Hmmmm. Nothing for the next several days. Then one morning the noise started and did not stop. I probed around and tracked it down to an area in front of the front passenger wheel. The water pump for the intercooler. Sounds reasonable. I popped the headlight panel off felt around. I was the horn making a weak honk/rattle whine?????? I reached in the car and pressed the steering wheel horn and no sound. After a bit the noise stopped. I pressed the horn and now it made the same noise. That was it, the horns were somehow making an anemic sound. Really bizarre. I disconnected the horns and that took care of it. I have not got a clue why it would do this. Tomorrow night I am getting the car ready for Viper day so while I have the car up in the air, I will check it out.

There have been reports of a week horn after a Paxton install, which I did experience but the horn going off on its own???. I ordered the horns from Griot’s so hopefully I’ll get it figured out. Still make no sense to me but it was definitely the horn going off and making a weird noise. So anyway my suggestion would be to sound your horn and see if it sounds like the noise you have been hearing. I thought about posting this but it though it too strange, but maybe you have the same problem. ???????

 

[VPRTKMIKE]

i have also seen this. for some strange reason if you use the supplied bracket the horns cut out,but loosen the nut and it works fine.i actually make up new brackets anyway so i never really figured it out.

 

[Viper X]

Glad your airbox was not filled with oil. Mine once was. I have now solved that problem.

As you stated, the miss problem may be vacuum related. I ended up putting clamps on all of my vacuum hoses at each connection and felt a good increase in throttle response and drivability. It was easy to do and it works. Something you might try.

You may also have some sort of tuning problem, as you stated when moving from open to closed loop operation. This sounds most likely, but a small vacuum leak could still be present.

Mine is now running so good that I think I burned up the clutch tonight. Keep after it and let us know what solved the problem.

Dan