[01MGGT]

Ok so we are still working out the tune but I was curious about something, I have been having surging/hesitation at WOT while trying to get the boost up. With my mods what are the chances the bypass valve isn't up to snuff? It's brand new and is the little plastic bosch that comes with the vortech kit. The car will start to pull hard then kind of hesitate and then pick up again and it kind of goes back and forth. I am going to throw some tr6 plugs in there gapped at .34 and see if that helps as I left the stock plugs per the vortech install instructions. I am on a pretty rich tune and tend to be around 11.0 or a little richer. Third gear is the worst....it it's like on the boost gauge it will climb to like 2 psi and back down then jump up some more to maybe 4 or 5 psi and so forth. I can't find anywhere it would be leaking. I even moved the vacuum for the bypass to several places with no luck. Everynow and then the stars will align and the car will run like a damn raped ape!

[Shaun03GT]

Hmmm, Im not to sure. Sounds like fuel imo. Mine kind of does that, but my Fuel rail pressure sensor is shot. If I hit it in 2nd or 3rd at like say 2500rpm, it will lag/hesitate for like 3 seconds then pick up. But my car hasnt seen half throttle since I got the fuel rail pressure sensor malfunction code.

Its possible that the bypass valve isnt shutting all they way. I dont think it is spark plugs, but it doesnt hurt to change them.

Hopefully someone else can chime in and help you out man, good luck.

[sharkbait]

I think its fuel aswell. I had the same issue.

[01MGGT]

Thanks for the fast replies. I will have to datalog the fuel and see what that shows. what did you do to correct yours sharkbait?

[tbirdscwd]

Originally Posted by 01MGGT Ok so we are still working out the tune but I was curious about something, I have been having surging/hesitation at WOT while trying to get the boost up. With my mods what are the chances the bypass valve isn't up to snuff? It's brand new and is the little plastic bosch that comes with the vortech kit. The car will start to pull hard then kind of hesitate and then pick up again and it kind of goes back and forth. I am going to throw some tr6 plugs in there gapped at .34 and see if that helps as I left the stock plugs per the vortech install instructions. I am on a pretty rich tune and tend to be around 11.0 or a little richer. Third gear is the worst....it it's like on the boost gauge it will climb to like 2 psi and back down then jump up some more to maybe 4 or 5 psi and so forth. I can't find anywhere it would be leaking. I even moved the vacuum for the bypass to several places with no luck. Everynow and then the stars will align and the car will run like a damn raped ape!

Put a colder plug in there. Not worth the risk of detonation under boost, trust me. If your A/F is at 11.0:1 then you are getting plenty of fuel and doesn't sound anything like a fuel pump problem, but it's worth datalogging your rail pressure. It's possible your bypass isn't working properly, or you might be blowing the spark out on those stock temp/gapped plugs once you get into boost. You need to have those things like you said in the .034-.032" range. You might also be detonating. What does your tuner have your spark borderline table set at above 2500 and 80% load? What octane fuel are you running?

The chance of your bypass not being big enough are 0, because it close normally no matter how much pressure you are running. The problem you will run into when you get into more pressure is that when it opens after WOT, it will not vent the pressurized air fast enough. You would notice this after WOT not during.

[Shaun03GT]

The datalog might not give you enough information. Because my fuel pressure is relativley good. It jumps around a shit load, but ajm told me to look at the long and short term fuel trim. Do you have a wideband? That would be helpful because you could see if its runs lean at that moment when it hesitates

[Shaun03GT]

Originally Posted by tbirdscwd Put a colder plug in there. Not worth the risk of detonation under boost, trust me. If your A/F is at 11.0:1 then you are getting plenty of fuel and doesn't sound anything like a fuel pump problem, but it's worth datalogging your rail pressure. It's possible your bypass isn't working properly, or you might be blowing the spark out on those stock temp/gapped plugs once you get into boost. You need to have those things like you said in the .034-.032" range. You might also be detonating. What does your tuner have your spark borderline table set at above 2500 and 80% load? What octane fuel are you running? The chance of your bypass not being big enough are 0, because it close normally no matter how much pressure you are running. The problem you will run into when you get into more pressure is that when it opens after WOT, it will not vent the pressurized air fast enough. You would notice this after WOT not during.

Good point, I didnt realise he didnt change to a colder plug. That could very well be a problem too.

[sharkbait]

Well all that stuff went away when i got a new fuel system and a tune.

BUT, after re reading your post. You should switch to copper sparkplugs. IF you havnt yet that could be your issue right there. Spark blowout feels like a surge at WOT. Try changing to a colder copper plugs and tell me how it feels. I did it and it got rid of all the spark blowout.

[Shaun03GT]

sharkbait, why are you selling your car? Seems like a lot of people are starting to sell there car. Only way I would sell mine, is if I could buy a 2002 ZO6.

[wishIhada5.0]

Originally Posted by Shaun03GT Hmmm, Im not to sure. Sounds like fuel imo. Mine kind of does that, but my Fuel rail pressure sensor is shot. If I hit it in 2nd or 3rd at like say 2500rpm, it will lag/hesitate for like 3 seconds then pick up. But my car hasnt seen half throttle since I got the fuel rail pressure sensor malfunction code. Its possible that the bypass valve isnt shutting all they way. I dont think it is spark plugs, but it doesnt hurt to change them. Hopefully someone else can chime in and help you out man, good luck.

Originally Posted by sharkbait I think its fuel aswell. I had the same issue.

+1...mine is doin the same thing and it is def a fuel problem! Try the cooler plugs too...it cant hurt lol

[01MGGT]

Threw a p0172 for rich bank 1. Changed the plugs with the TR6 gapped at about .35 so we will see how it goes from there...

[01MGGT]

Double post FTL

[Shaun03GT]

Mine got Lean in bank 1 , and pending lean in bank 2. But before when I brought it to my tuner it said rich in Bank 1. So Im conviced my fuel rail pressure sensor is all messed up and causing some effed up things

[BakerFX4]

when mine was running rich, after 3000 rpms, it would start this bucking/surging shit and when i let off it would go lean. Ended up being a leak in my intercooler piping that caused it all.

[91sleeper]

gapping may help I saw where that you were going to try .35 that sounds good I normally run.30 on step colder is also a good move. I use regular the copper autolites.

[sharkbait]

Originally Posted by Shaun03GT sharkbait, why are you selling your car? Seems like a lot of people are starting to sell there car. Only way I would sell mine, is if I could buy a 2002 ZO6.

I am no longer selling my car. I decided that im better off building her then trying to sell her.

[01MGGT]

Ok sent me a new tune today. He changed the MAF transfer function and some fueling and it's doing a ton better so far. wideband says about 10.8-11.0 at wot but I have a small exhaust leak upstream of the wideband 02 so we are trying to wait to get that fixed before pulling to much more fuel. Just to be safe. The plugs also seemed to make a huge improvement. I will keep you guys up to date on how it does