Sputtering at 15psi+?? also Profec B issue

[suprafanatic]

So recently my car has been sputtering or cutting out alittle at anything over 15psi. At first it wasnt bad, it was more of a poping sound than a power loss. Then it got worse and almost sounded like hitting rev limiter and had a slight power loss. I figured it might be some bad spark plugs so i got some new autolite 3923's and put them in. However, it only helped alittle, the sputting still occurs at 15+psi. If i run under 15psi it runs very smoothly. Any idea what else could cause this issue? AFR reads 11.5 at WOT.

My second issue is with my profec B electronic boost controller. I just installed it today. The issue is through 1st 2nd 3rd and 4th gear it the car over boosts and wont go by what i have the Profec B set at, however, in 5th gear it works perfectly and will hold low boost throughout the gear. Its almost like in lower gears it just boosts to fast and just doesnt open the wastegate up. And this is even with the Balance control set to sharp all the way. any ideas on this problem?

 

[jdub]

Autolite 3923's are 1/8" shorter than stock length...your plug wires might not be making good contact and cause an arc.

Where is your fuel pressure set?

 

[CoopMK3]

Dude that sucks, after all the trouble we made those people at autozone go through to find those

 

[CajunKenny]

I'm running the ProfecB Spec II. I had a couple of issues with mine also. The first thing I did was turn the controller off and made sure everything boosted normally. After confirming that my problem only occurred with the controller on, I then set everything back to the factory defaults and adjusted one thing at a time starting with boost adjustments. Then I took out the boost spikes by adjusting the gain and later messed with the other features/settings.

One thing I did find out is that if my boost settings are not set higher on the controller than what the wastegate is sprung at, I get a VERY noticeable chatter or clicking sound from the valve unit.

I probably stated the obvious; but, that's all I got.

 

[suprafanatic]

well i have NGK wires, they have been used for a while they may need replaced. i guess i could start there.

with the profec B in 5th gear i was actualy able to hold boost lower than what the wastegate was set at, but in any other gear lower than 5th it just over boosts to 20psi+, even with the controller unit turned off. One thing i may have wrong with the set up, where does the vaccum line on the back of the controller unit go to? i have it T'd to the BOV vac. line, is that a correct place to put it?

 

[suprafanatic]

Autolite 3923's are 1/8" shorter than stock length...your plug wires might not be making good contact and cause an arc.

Where is your fuel pressure set?

My fuel pressure at idle is 34-35.

Do they make wires that are alittle longer?

 

[jdub]

The problem I've seen with the 3923's is with after market wires...less so with stock. The solution is to use NGK copper plugs vs the Autolites.

Is that FP with the vac line on or off?
Do you get an FP increase when you disconnect the vac line? FP with the line disconnected?

 

[suprafanatic]

That is with the vac. line connected, it will increase when disconnected.. by how much im not sure.

If it is the wire and plug combination why would it just randomly start doing this and not from the get go?

 

[jdub]

Your FP is high...drop it down to 30 psi vac on. Check the TSRM specs to see what it should be vac off.

Concerning the plugs - I'm just telling you what I know about the Autolites and I'm not there to see what else you may or may not have done. To be honest, I never have understood why guys use them.

 

[suprafanatic]

ok i can turn down the FP. i just changed the fuel pressure last night cause i check the gauge and it was at like 24, i thought maybe there wasnt enough FP so increased it but the sputtering was still there. Im pretty sure it has something to do with the spark. I honestly haven't had the best luck with the autolites either, they seem to go bad on me rather quickly. Where can i pick up the NGK coppers? seems like everywhere i looked didn't carry them.

 

[grimreaper]

orillies (sp?)

 

[suprafanatic]

so should i replace the plugs agian with NGK coppers and do the wires? or should i do the plugs first and see if that fixes it? i have two sets of NGK wires, both used though
Also, should i get a colder plug? if so what specifications?

 

[teedoff00]

I use the NGK 6097's at 16psi and and it runs great! I had NGK iridiums before and I got sputtering (not sure if it is what you are experiencing) but it solved that right away. Boosts smoothly all the way to redline.
Good luck.
P.S. As to the wires, I run Magnecors and they have been great!

 

[grimreaper]

i thought iridiums cause glow plugging...

 

[CajunKenny]

One thing i may have wrong with the set up, where does the vaccum line on the back of the controller unit go to? i have it T'd to the BOV vac. line, is that a correct place to put it?

The line from the back of the controller unit should be T'd into the FPR Vac line. Mine is T'd into the line coming off the back of Intake Manifold.

 

[jdub]

i thought iridiums cause glow plugging...

They can, but usually only under extended high RPM runs. For a relatively stock set-up the iridiums are fine to use.

SF - Get a multimeter and test your plug wires and coils per the ignition section in the TSRM.

 

[ForcedTorque]

SF - Get a multimeter and test your plug wires and coils per the ignition section in the TSRM.

I was surprised at the simplicity of testing ignition parts while following the TSRM. Even I could do it:naughty:

 

[suprafanatic]

ok well i went to advanced auto today and had them order me some NGK coppers. they will be in tomorow morning, so when i get around to swapping those in we'll see how she runs.