I've gone crazy over this and I'm ready to ask questions. Yes, I've talked to Stillen.

On acceleration, under boost, my car hesitates precisely at 3000 RPM. It's fine through out the entire RPM range before and after that spot. Also, if I'm cruising along at say 50 MPH and push the clutch in and let off the gas it will die. I usually just dump the clutch to restart it. I'm open to opinions and suggestions.

I have a 2004 Base 350Z with Stillen Stage 3 Supercharger. I also have Stillens intake (giant K&N air cleaner) and cat-back exhaust.

Thanks.

 

It looks like I have the same problem as the guy in this thread: https://my350z.com/forum/forced-indu...ion-issue.html

So, should I get an aftermarket ECU (a Haltech or?) and have it tuned by a pro?
The Stillen piggyback box has no end user adjustment and I don't know that any pro shops can tune it.

On another note, I have a Bluetooth OBD scantool and it seems to read the computer awfully slow. Is the stock ECU just too slow to correct the map (and maybe the root of the problem?)? Looking at other users of the same product, they get faster read times from their cars. I can only read maybe 4 sensors real time. Adding more just makes it read slower.

I'm lost.

Additional info: No codes, less than 60k miles, boost gauge reads about 9PSI max, this only happens when the engine is warm and the computer starts reading the O2 sensors,etc

 

Talked to Stillen........again.
He said buying the stage 4 will fix my problem. mhmm. Or buying a UpRev and Osiris tune and taking it to a local shop. The local shop says I need new injectors, fuel pump, plus the UpRev and a few pulls on the dyno so they can tune it.....to the "tune" of $2500.

With Stillens stage 4 I pay about $1000 and I can't tune it.
With the UpRev, I pay ALOT more but I can tune it..right?

Some advice....

 

A tune should definitely help....but $2500? Is that everything including Osiris tune, injectors/pump and labor?

 

Yes, and an aftermarket MAF? sensor.

What REALLY bothers me is the "Stillen Supercharger Tech" said he was surprised I hadn't blown the motor up. WHAT!? I'm using the factory supplied box! They never said I would need to take it to them.I did everything right. Now I have to pay more to fix this expensive S/C? I'm more than a little disappointed with them. If I was in California I could take it to them, but since their box is locked I can't take it ANYWHERE else I'm screwed. Stupid, they should have made the box tunable.

I was hoping someone here had the same issue and had the fix since this S/C has been out for awhile.

I don't know what to do. I've already spent 8K on aftermarket crap (mostly Stillen). I'm feeling nauseous about spending another 3k to fix it.

 

Just got off the phone with the local shop. It's more like 3K all done, but he said if I do the injectors and fuel pump install myself I can save a lot and it should be around $1500 instead.

That guy sounded like he knew what he was doing and I liked talking to him. http://www.tunedbypsi.com/

 

Yeah labor is an expensive part of the deal...1500 for a tune is still on the high side but a little more realistic...

 

The actual Tune on the dyno is only 600. The injectors, fuel pump, UpRev license, and MAF are about 1350.
So if I install this stuff and trailer it down there for the tune I should be set. Dam. All it takes is money right?

Any other options?

 

i had a similar problem on the dyno. my car would break up around 5500. replaced my coilpacks and it worked fine. it could be alot of things

 

Ya, it could be so much. My guess is the sucky stillen tune and management is having an issue going from closed loop to open loop kind of like the Utec does causing the hesitation.

Without seeing logs of a/f and all that stuff it would be impossible to find out why. Could be lean, could be rich, could be detonation, could be electrical, on and on.

 

Uprev will fix your problem. A stillen stage 4 package will do nothing to help you since the problem lies within the tuning not the SC.

 

Yeah, I'm planning on the UpRev tune. It makes more sense to me. Unfortunately I have to buy a bunch of other crap to do that.

Is there any way I can make the car run in open loop mode until I can get it fixed since it runs fine when it's cold (open loop)?

 

Anyone? I thought of connecting a resistor in place of the coolant temp sensor to fool the ecu. Anyone do this?

 

I was reading through old threads and realized I could disconnect one of the O2 sensors to get the car running open loop.

Question is, which one? Upstream or downstream? Both banks or just one?

 

running in open loop will make it worse if the car isn't properly tuned. Open loop will turn off o2 corrections in vacuum which is probably the only thing keeping it running at all (it allows +/- 20% changes in fuel to be automatically corrected)

 

I doubt it's an open/closed loop hiccup -- SS box is nothing like the UTEC. I'll place money there's a ridiculously lean spot around 3k rpm. Get tuned asap.

 

That's the same thing the shop told me (leaning out) but why at JUST 3k? TRUST ME I'll get it tuned as soon as I can.

So the only reason it runs so well when it's cold is because it's really rich? That's what I'm trying to accomplish until I get it tuned. I must be using the wrong terminology, sorry.
How can I keep it running in the "cold mode" until I can get it tuned?

Sorry to be a bother, but I just need to wait a couple of weeks to get the cash. I promised not to use the credit card

 

ECU adds fuel as the temps are colder. Be light on the throttle and don't go over 3krpm.

 

A drop in pump for your setup should be in the neighborhood of 100-150$ if you diy.
Injectors (drop in solution) would be $500 tops.
I think everyone agrees a return line would be a smart add, but it's not necessary on your power levels.
It may be worth your time to look into another ecu solution, one that is map based. Depending on which osiris license you choose, it could cost you up $1200 (700 for pro, 500 for maf). Then the cost of the tune. I'm sure you could find a redbox haltech for near that price, and it would be easier (IE faster=less money) to tune (speed density requires an out of boost tune, then just uses IAT and the in haltech MAP sensor to determine fueling in boost).
There are also other cheaper MAP based piggy backs you could consider if you don't want to spend a lot (understandable on a simple setup like your car).

 

Thanks for the good advice! Are there any choice piggybacks that you can point me too?
I plugged in a loose coolant sensor so I can get by. I know it isnt proper but it works for now.