Acceleration Problem

[scramblr]

***Edit: Consolidated everything to this first post.

Intermittently, while accelerating I'm getting a shudder throughout the car at the same time it's backfiring some and the car doesn't have full acceleration. The boost gauge goes crazy with the needle jumping all over the place as does the AFR. Goes from Rich to Lean...back and forth. If I let off the gas and wait a few seconds, it all goes away and the car runs like a champ. Then it does it again after awhile. Driving without putting the car under load, i.e., staying out of boost is fine most of the time, it's when accelerating into boost...but not every single time. I can also go WOT to 15psi with zero issues.

I previously had a vac leak which I fixed by getting a new vac actuator. There's no other leak that I can find. AFR, idle, fuel pressure, fuel pump DC, water temp, oil pressure, IAT, vac (22) and max boost (15) are all fine.

Also, I got a hold of Saleen tech and although they could have sold me a bypass kit, they don' think that's the problem. Just for a test, they suggested to back out the actuator set screw one turn just in-case the bypass wasn't fully closing. Not only that, but I put the 3.4 pulley on dropping from 15psi to 8psi to reduce the pressure and neither change made a difference.

So far I've tried:

New HT0 plugs at .30
New Coil Packs
New O2s
Different CAI, MAF Housing/MAF
2 tunes from two different tuners (data logged)
About 5-7 test tunes (thanks lito) and 10-15 datalogs concluding that it's not a tune issue
Compression test O.K
Swapped Injectors
Snif test of coolant tank and came out positive for hydrocarbons.
Different PCM and test tune (thanks again lito) (need to figure out how to send beer to Venezuela)
Leak Down Test came out good


**Update: Here are a few videos highlighting the problem. Tried to capture AFR, Boost/VAC, and Fuel Pressure. Look at the boost gauge go bonkers. And yes...the autobahn rocks!!!

In 5th accelerating problem @ 1:13 and 1:36




In 5th accelerating




Pull in 3rd no issue

 

[scramblr]

Any ideas? Unfortunately I don't have anywhere to take the car here, so I have to figure this out on my own. Any input would be appreciated. Thx...

 

[lito]

Nothing like having a log, email me your strategy so I can send you a config file and go from there.

 

[JesseW.]

i'm unfamilar with the saleen supercharger, but it sounds like you may have a malfuntioning bypass/blow-off valve.

 

[scramblr]

Nothing like having a log, email me your strategy so I can send you a config file and go from there.

Much appreciated lito. I emailed you two logs.

i'm unfamilar with the saleen supercharger, but it sounds like you may have a malfuntioning bypass/blow-off valve.

I'm also not familiar with the internals, but the vac actuator is brand new and the boost gauge is reading correctly until this anomaly starts happening then the needle is all over the place.

 

[JesseW.]

the bypass poppet could not be seating correctly everytime allowing it to bleed boost or flutter everyonce in a while. i was having a similar problem with my vortech that had a bosch bypass. i changed it out for a turboXS bypass and it seems to have stopped the problem.

 

[scramblr]

Well, JesseW and Lito (which is a life saver by the way...yes, that was a nut swing) have come to the same possible conclusion that I may be having an issue with the bypass valve.

I've only, seen pictures of the internals of a Saleen an now I can't find them. Read a couple of threads where Cekim was talking about it and Hawgman may have replaced one, although it may have been the vac actuator and not the bypass valve.

Sooo, long way of getting to the point....does anyone have an inputs on checking/testing/replacing the bypass valve or the spring associated with it? See first post and note that my vac and boost are spot on after I replaced the vac actuator. TIA...

Does this look like what I may need, minus the actuator?
http://speedlab.saleen.com/store_co...112607&store_id=1&dept_id=981&product_id=7096

 

[kevinatfms]

could be a bad coil driver in the pcm. the only way to tell is when its misfiring see if the ground side of your coil wire actually gets grounded by the pcm.

you could hook up a noid light and wire it to the driver side wiper. it will flash repeatedly. if it does not flash while the problem is occuring i would bet the coil drivers in the pcm are bad.

 

[scramblr]

could be a bad coil driver in the pcm. the only way to tell is when its misfiring see if the ground side of your coil wire actually gets grounded by the pcm.

you could hook up a noid light and wire it to the driver side wiper. it will flash repeatedly. if it does not flash while the problem is occuring i would bet the coil drivers in the pcm are bad.

Thanks for the input, I may give that a try. But you'd think I'd be getting some sort of code.


**Update

Did a compression test today and it came out fine. *However, we also tested the air in the coolant reservoir and it came out positive for CO2. *We ran the test twice and it was positive both times. *I'm going to do a leak down test tomorrow to see if I have a head gasket leaking. *There is no oil in the coolant, nor any coolant in the oil. *Again though, what's weird is if there is a leak in a head gasket, why is the problem only happening intermediately and not getting an misfire codes?

So far I've tried:

New HT0 plugs at .30
New Coil Packs
Different CAI, MAF Housing/MAF
2 tunes from two different tuners (data logged)
About 5-7 test tunes and 10-15 datalogs concluding that it's not a tune issue (Lito ROCKS)
Compression test O.K.
Swapped Injectors

 

[scramblr]

I need a way ahead here guys. Datalogs didn't tell us anything. I consolidated the issue and updates in the first post. Considering going to a Ford dealership and have them run diagnostics on it to see if they can find something. Unfortunately they don't have much experience with these cars here.

Any other ideas on what I can check?

 

[Mustang30212]

Man...wish I could help. Sorry the coils didn't help.

Have you checked your O2's?

RH

 

[scramblr]

Man...wish I could help. Sorry the coils didn't help.

Have you checked your O2's?

RH

Yep, new O2s, both sides. I keep doing searches for similar issues that people have had and keep coming back to misfires with no codes pointing towards possible electrical issues. I'm gong to go over all the wiring to see if there is something there.

 

[lito]

It was tested in open loop and nothing.

Alex, I think that you should do that plus a PCM test, do you have a friend with a 05/06 that could let you borrow his PCM?

 

[scramblr]

It was tested in open loop and nothing.

Alex, I think that you should do that plus a PCM test, do you have a friend with a 05/06 that could let you borrow his PCM?

It's possible that I could borrow a PCM. What does that involve? A new tune for that PCMs code with my XCAL2 and then swap it back?

 

[lito]

You've got mail.

 

[bullitt boy]

subscribed. Please keep us posted.

 

[scramblr]

Looks like Hawgman had a similar issue a few years back and it was the PCM. He swapped it out and it fixed the problem. Coincidentally, I received an email from lito asking if I had access to another PCM to test my car with. So I'm on the hunt for a PCM I can borrow. Anyone feel like mailing theirs to Germany for a quick test? Eh, figured I'd ask.

 

[scramblr]

Does a 2010 PCM swap into a 2006 vehicle? This is just for testing purposes.

 

[gtcs07]

I tried swapping mine when i put in the new motor and the pats system locked me out and the car wouldn't start

 

[scramblr]

I tried swapping mine when i put in the new motor and the pats system locked me out and the car wouldn't start

Swapped it out with what year PCM? Just learned that 05-06 can swap as 07-09 can and 10 is like the lonely child on it's own. I need to fins an 05/06to borrow.