Paxton Help - Again

[ViperGeorge]

This may be a long post but I want to provide as much info as possible. Hopefully one of you Paxton experts will have an idea on what my problem is.

I was tracking my 2006 Paxton coupe this past weekend. Car ran great on the first day and the morning of the second. The event culminated in a solo competition. When I went out on my solo run on the clock I immediately noticed the car was not running up to potential. MPH was down, RPM were down as compared to earlier sessions. On my third lap the car backfired and stuttered. My times sucked.

I hooked up my code reader and found the following pending codes -P0300 multiple random misfires and P1391 intermittent loss of camshaft or crankshaft sensor input. I cleared the codes and drove the car. It still felt weak. RPMs did not rise smoothly and seemed to stutter. I did not notice what the boost was doing. I have a PLX multi gauge with left and right Air Fuel, boost, and OBD II connection. I display L/R Air/Fuel, Boost, and Intake Air Temp from the OBD II data stream.

Called it a day and drove home. Car behaved normally on the highway just cruising. Today I checked all the connections between the PCM and the Split Second box. The person that installed the Paxton used butt connectors I removed them and soldered the connections with shrink tubing over top.

Took car out on highway and car felt the same - fine just cruising but down on power when I pushed it. RPMs would rise in a stuttering way. Threw a P0113 code - high voltage Intake Air Temp sensor. I could see the Intake Air Temp on my PLX OBD II gauge and it was bouncing all over from 32 to 109 degrees. Ambient temp was around 85. Came home and pulled out Intake Air Temp sensor, it was covered in oil. I cleaned it with circuit cleaner. Took the car out again and the IAT was normal at 107 degrees with no bouncing around.

Car still ran like crap. Boost never went above 1.9 lbs. RPMs still stuttered under throttle. I have had a problem in the past with oil blowing out of the bypass valve. Sent the blower back to Paxton for seals. I don't think they did anything with the unit before sending it back to me (their service leaves something to be desired IMO).

On my last test run fuel pressure never went above 75 psi (pressure is 52 psi when not in boost) but given the boost level I saw I suspect this is ok. Under full boost (7-8 lbs) it will normally go to 95 psi. I did put 12 volts to each of the auxiliary fuel pumps that Paxton provides and they both spin up as soon as they see voltage. I know the Split Second box kicks on each fuel pump at different boost levels. I think the boost never hit the level to kick on the second pump. Sound right??

So here is what I think so far. The blower needs seals, the IAT sensor should not be covered in oil and I should not be seeing an oily mess around the bypass valve. Oil should not blow out the bypass valve to the level I see. But the question is will bad seals effect maximum boost? Not sure why boost level never went above 1.9 lbs unless it is some problem internally with the blower. This is like a chicken/egg thing. Is there a problem with the blower that is keeping boost down or is there something else wrong with the engine that keeps boost down?

My A/F under 1.9 lbs of boost and with 75 psi fuel pressure was very high 10s to low 11s. Plenty safe and indicative that there was adequate fuel pressure for the amount of boost I had. This A/F ratio is normal for the tune I have. Problem is that the boost never rose above this level and car was way down on power.

The P1391 pending code may have been due to bad connections due to the butt connectors which were covered in oil from the bypass valve. I suspect this because I had a similar problem in May while competing in the Cannoball One Lap of America. I played around with PCM connectors and wires and the problem went away. I suppose the camshaft or crankcase sensor may actually be going bad though so I'll change both when I take the blower out for new seals. You can't get to the camshaft sensor unless the blower comes off. The crank sensor is easier.

Please give me your thoughts. I want to get this car running like it should again. Are there other things I should look at? I think the Split Second box is working given that it turns on at least one of the fuel auxiliary fuel pumps but is there a way to test it? The Split Second box intercepts both the Camshaft and Crankshaft sensor input at the PCM and alters it based on boost levels. I guess if it is failing it could cause a P1391 code. However, usually electronic components either work or don't, they typically don't work sort of. Back in May I spoke to the manufacturer of the Split Second box and they said if it failed the car would not run at all. Connections may be intermittent though so I'm leaning towards a bad connection that caused the pending P1391 and P0300 codes.

That's about all I know.

 

[RTTTTed]

Anyway you could get it onto a dyno so that you could check the intale system for air/boost leaks? Perhaps the bypass valve isn't closing when the boost is supposed to close it and it's venting all the boost? Losing much of your air charge would cause the engine to run rich and run like crap.

Is there a Paxton tuner near you? They should be able to test the sc for boost?

Ted

 

[Bobpantax]

Who did the install? Are you running a stock kit? Do you have a swing arm oil pan on the car? Do you have a blower tune?

 

[ViperGeorge]

Ted, How would I know if the bypass valve is not closing? I've thought about this as a possible cause but I must say I tend to think that all of these issues have a common cause. Could the oil blowing out of the blower cause the bypass valve to fail?

Bob, The install was done by one of our club members in IL. He has done several and it was done 2 years ago. It is basically a stock Paxton install except that the intercooler heat exchanger was custom made and is much larger than the small one that comes with the kit. I also have a high flow intercooler pump from DC Performance. DC also reflashed my PCM with their supercharger program. The car has a 170 degree thermostat. The only thing that I wish the installer had done was to solder the connections at the PCM. Other than that the install was really done well. The bypass has always blown oil. I've got a newly rebuilt engine with 5000 miles on it. Forged internals and ATI damper. I use a catch can system on the track but use the stock PCV setup on the street to eliminate the oil smell. I use valves to switch between the two. When it was running correctly (although it still passed oil from the bypass) it made 646 RWHP.

 

[ViperGeorge]

The reason for the new motor by the way is I blew it at Pocono last year. I think it may have been related to the seals on the blower. Oil in the intake lowers effective octane. Motor showed signs of detonation. I did add the swinging oil pickup when the motor was rebuilt (actually replaced, holes in the block really can't be repaired)the motor was replaced by Arrow with one setup up for a supercharger. Stock compression but with Diamond Pistons for a blower (lower ring lands), Carillo rods, swinging oil pickup off an 08, ATI damper, and chrome molly push rods. They also provided fittings in each valve cover to vent to a catch can.

 

[RTTTTed]

So the only oil in the intake is inside the Paxton?

My Paxton has no oil problems or leaks.

I suggested a Paxton tuner so that they could change the bypass etc. if they needed to. I'm just getting familiar with my Paxton now as I've taken the car apart and inspected all the various parts of it. But, it works perfectly (thank god) so I have no troubleshooting experience yet.

Ted

 

[ViperGeorge]

Ted, The oil seems to be coming from the bypass valve which is located on the driver's side below the intercooler tank. It blows so much oil that the engine compartment is a mess and it drips on the floor. Given this I sent the blower back to Paxton for new seals; it was about a year old.

They gave me a hard time because they said that some plastic seal on the pulley was missing and it therefor would not be covered under warranty. I freaked out on them because they wanted $420 to do the job. They also said my pulley was bent and needed to be replaced for $110. After my rant they agreed to do the seals under warranty. I never took the stupid seal off the pulley or changed the pulley.

I told them I would pay for the new pulley even though I think they damaged it when they received the blower back. Bottom line is that they charged me the $110 for the pulley but never changed it. Got the same one back. I therefor assume that they really didn't do a damn thing to repair the blower either since it was blowing oil as soon as I reinstalled it.

This time I will tell them that I will pay for the repair. A ripoff but what am I going to do? Removing and reinstalling the blower is a real pain in the butt. Maybe I'll replace the bypass valve too.

When I removed the blower there was oil pooling in the output tubes from the blower into the intake.

 

[RTTTTed]

I feel for you. I know how you feel after paying big bucks and the product being defective, then getting a hard time from them over warranty and they sent it back without fixing it?

I think that you probably want to talk to DLM or DC performance as they won't get ****** around by Paxton. Those 2 tuners sell enough Paxtons that when they talk Paxton listens. Obviously calling Paxton yourself is a waste of time. Better get help from the Pros. Paxton wouldn't dare screw them over because Paxton wants all the tuners talking nicely about them. Phil/Plumcrazy swears by DLM in Florida and those guys are your best bet for getting action. Send it to them and let them check it out is my suggestion.

Ted

 

[plumcrazy]

im always gonna say DLM but DC and dont ever forget woodhouse for paxtons. those are the 3 to talk to for that SC. and all 3 are helpful too. call one of them

 

[mbccenter]

A oil catch can set up may help. The one time I saw that the car had a broken ringland.

 

[ViperGeorge]

A oil catch can set up may help. The one time I saw that the car had a broken ringland.

The car already has an oil catch can. It also has forged pistons designed for a supercharger, i.e. with lower ring lands.

 

[rich v.]

i've had a couple of problems along the way with my paxton car and they all led back to the split second box usually mounted under the dash. same issues: under heavy throttle sputtered real bad and eventually would barely idle and threw misfire codes. had paxton replace the box once and repair it the second time. not sure what causes it... i have rewired it several times too.
good luck!

 

[RTTTTed]

Gbatejan - if it was me (living where I end up being the 'tuner') I would make a block off plate and replace the bypass valve with it. Keeping my hand on the key to shut the engine down immediately if the boost comes up. Not sure if it's a plan you'd be interested in, but if very careful it would be a way to test the boost. The tune is for the bypass valve so it is possible to damage the engine if not careful.

As I said, I recommend a tuner ... but ... above is how I'd test it.

Ted

 

[ViperGeorge]

i've had a couple of problems along the way with my paxton car and they all led back to the split second box usually mounted under the dash. same issues: under heavy throttle sputtered real bad and eventually would barely idle and threw misfire codes. had paxton replace the box once and repair it the second time. not sure what causes it... i have rewired it several times too.
good luck!

That's interesting. I had thought the Split Second box would either work or not work. That's what the people that make the thing told me anyway. I know it kicks on at least one auxiliary fuel pump so it must be partially working if that is the cause. It hasn't thrown any more codes (other than the IAT high voltage due to the sensor being covered in oil from bad blower seals). However, the car continues to run like crap under heavy acceleration.

Today I pulled all the plugs, they look fine, changed the front O2 sensors on both sides, the Crank Sensor, and the MAP sensor. Will take the car out for a test in a bit to see if it made any difference. If not then I will assume the Split Second box has bit the bullet. That is a pain in the a$$ though as it is tough to swap out.

 

[Doug Supercharged Vipers]

I will help you!

 

[ViperGeorge]

I thought I had solved my problem but alas no. The vacuum line had come off the bypass valve. This had to be the problem but it wasn't. Boost gets to maybe 2.5 lbs now and fuel pressure gets to about 85 psi. Given this I believe that both fuel pumps are working and the FMU is keeping the pressure at 85 because that's all it needs at 2.5 lbs of boost. Car still doesn't accelerate hard, especially noticeable in third under load. RPMs do not rise smoothly and car seems to shutter a bit.

Applied vacuum to the bypass valve and it held vacuum - no issue. I therefor think the bypass valve diaphragm is intake and the bypass valve is ok. Not sure why the vacuum line was off, could it have blown off somehow?

 

[InjectTheVenom]

That last description sounds awfully familiar to what a certain single turbo car is experiencing, except when I pulled the vacuum hose of my waste gate I got full boost again without a hitch so you might still want to swap out that bypass valve just for the sake of investigation.
Also had the vacuum hose to my recirculation valve pop off once so things like that do happen. Only thing that I can think of is that air traveled the other way causing it to fly (usually they are not clamped on)?

 

[RTTTTed]

I still suggest calling a known Tuner. Since Doug Levin (of DLM) has offered help - you should give him a call. He has done many Paxtons and may already have the solution.

If the oil is an indication you need the Paxton rebuild and I bet Doug would make certain that it was properly done without you getting ripped off this time.

 

[plumcrazy]

trust DOUG LEVIN.

 

[ViperTony]

trust DOUG LEVIN.

Agreed......

 

[mbccenter]

Doug is very helpful on the phone. Give him a call.

 

[ViperGeorge]

A big shout out to Doug Levin for his phone support. Still have a problem but I'm making some progress. See below.

To recap, 2006 Viper w/Paxton, Forged internals, motor built by Arrow Racing (5000 miles on it), Random Tech High Flow Cats, Corsa Track exhaust, DC tune on PCM, catch can, 170 thermostat.

Have changed MAP, Upstream O2s, Crank Sensor. Cleaned Air Intake Sensor and checked spark plugs. All plugs look normal and the same. Soldered all connections from Split Second box to PCM.

Checked all vacuum lines and installed spring clamps on every connection. Did find a leak in the line to my PLX gauge sensor. Repaired it and all lines hold vacuum now with very little leak down. Boost now goes to 4.0 or so which is progress.

Could not remove blowoff filter to check plunger operation without taking out the tank. The clamp bolt is in a very awkward location and I could not get any kind of socket or wrench on it.

Car still does not accelerate properly under boost. Engine above 3000 RPMs feels like it is stuttering when under boost and does not have the power it used to. It may seem like a tuning issue but the symptoms only started over the weekend after a day and a half at the track. I can find no other obvious problem.

The car will accelerate smoothly to 5000 RPMs and beyond without boost.

For my last test ambient temp was about 85-90 F. Intake Air Temp was 111 F. A/F ratios on both sides under boost is about 11.0-11.2. I did not look at my fuel pressure but given A/F I would have to say it was fine. Last test I saw 85 psi with about 2 lbs of boost so I think both pumps are working.

I checked all output tubes on blower and every vacuum line I could find including the ones under the throttle body. No obvious defects anywhere and no Trouble Codes reported by PCM.

I'm stumped. I sent this same info to Doug via PM so hopefully he will have some other ideas.

 

[ViperGeorge]

Also spoke with Dan from DC Performance. Gotta love all these guys. They take the time to help you out. Still have problems but Dan said basically the same thing as Doug.

 

[mjorgensen Woodhouse]

Sorry I have been out, I did get your PM and meant to call you today, but never got caught up in one day. Did either Dan or Doug suggest that to test the cats to see if you melted them down at the track? They may act ok without boost but can't flow enough under boost. Would not be the first ones we have seen especially with the RT.

 

[RTTTTed]

and They said ...?

Ted

 

[plumcrazy]

im betting doug asked about the cats or will... dont ask how i know this...lol

 

[InjectTheVenom]

Did you also pull the flexible parts of the vacuum hose and bend them to see if they have hairline ruptures, especially in corner bends?
Don't think the car is old enough yet for dried out hoses but still..

 

[ViperGeorge]

Doug and Dan both suggested checking the blow off (or bypass) valve plunger. Couldn't get to it though with the way the clamp is on the filter. It will take a much more significant dismantling. They both suggested checking for leaks in the vacuum lines particularly the ones feeding the Split Second box. I did find a leak at a tee that fed my PLX boost sensor. Repaired it and that helped boost level (now at 4.0 lbs at 4000+ RPMs) but not the way the car ran. They also suggested checking the output tubes from the blower to make sure they didn't blow off. They didn't.

I've also heard from Mark at Woodhouse. He and the others also wonder if the Cats are plugged. Dan told me how they would do a back pressure test on them but I don't think I have the capability to do that. Dan said that if they are plugged the car would not necessarily throw an inefficient Cat code. Hopefully someone can tell me how else I might determine that the Cats are the problem other than a back pressure test.

I can monitor a lot of stuff from the OBD2 stream using my Autotap software. It can record it when I run the car. The more stuff you record though the lower the sample rate. This is a PCM limitation. Given this I was thinking of recording Manifold Absolute Pressure and Timing Advance. With this data do you think someone could tell me if the Split Second box is working? I will also use AutoTap to check Throttle Position Sensor function although I suspect this is fine.

At this point I'm leaning toward plug Cats. I suppose they could have plugged on the last good track session I had. Would downstream O2 sensor voltage be a clue here? I can also record that with AutoTap.

 

[ViperGeorge]

Throttle Position Sensor seems to operate smoothly, no hesitation or spikes in the graph from AutoTap.

 

[doug fresh]

Melted or clogged cats would show higher boost levels due to restriction, thats how i figured out mine were melted.