Potential problem? (flutters at startup)

[Red&Black_Attack]

Everyday when I go to start my car it misses/flutters until after it sits and runs awhile. Could this be a potential problem somewhere in the fuel system?

It quits after it runs and rev it up some after a few seconds/minutes.

Also when I went to swap to my 97 pcm it wouldnt even run on that tune at all. It was tuned via pcm4less for bolt-ons and 4.10's etc. Almost the same issue but far worse and wont run at all on it.

Any help would be highly appreciated. :)

[cam98aro]

Re: Potential problem? (flutters at startup)

sounds like you have a leaky injector

[Blizzard242]

Re: Potential problem? (flutters at startup)

Your car is in open loop until it warms up and receives fueling corrections from the o2 sensors where it enters closed loop. Basically when it's in open loop it's only fueling based on calibrations to the MAF and other sensors but not the o2 sensors.

In your case, sounds like a poor tune to me.

[Red&Black_Attack]

Re: Potential problem? (flutters at startup)

Your car is in open loop until it warms up and receives fueling corrections from the o2 sensors where it enters closed loop. Basically when it's in open loop it's only fueling based on calibrations to the MAF and other sensors but not the o2 sensors.

In your case, sounds like a poor tune to me.

See this tune has happend twice, they tell me there must be something wrong with my car cause this is a generic tune used on many v6's w/out issue.

So what the car's doing is completely normal? It's really annoying... I have to deal with it everyday.

[bigbrian442]

Re: Potential problem? (flutters at startup)

It is possible what you have done to your car requires custom tuning. MAF tables need to be tuned even from very small changes like free flowing exhaust.

[Red&Black_Attack]

Re: Potential problem? (flutters at startup)

Probably right. I've got headers and the whole 9 yards. Been untuned since then... Tried getting a tune from pcm4less and it wouldnt even run.

[Blizzard242]

Re: Potential problem? (flutters at startup)

I would never trust a "pre-fabbed" tune. Every car is different so unless they have the car in their possession to tune it, I can't see it being very accurate.

Invest in a wideband and HP tuners so you can tune it yourself. Expensive yes, but extremely worth it.

[Red&Black_Attack]

Re: Potential problem? (flutters at startup)

I used to have HP tuners. Wish I didnt sell... Didnt have a laptop at the time.

I thought You didnt need a wideband to tune it though?

[Slowside]

Re: Potential problem? (flutters at startup)

You dont, but then your relying on degrees of knock, and thats not nearly as accurate. and E85 is pretty knock resistant.

[Blizzard242]

Re: Potential problem? (flutters at startup)

Yes, you need a wideband. You can tune part throttle or any other condition around the 14.7 a/f ratio but anything out of that range, like WOT is impossible without a wideband.

[Slowside]

Re: Potential problem? (flutters at startup)

Yes, you need a wideband. You can tune part throttle or any other condition around the 14.7 a/f ratio but anything out of that range, like WOT is impossible without a wideband.

I used to tune a 6bolt gst, adjusting timing and fuel using knock.

[Red&Black_Attack]

Re: Potential problem? (flutters at startup)

Yes, you need a wideband. You can tune part throttle or any other condition around the 14.7 a/f ratio but anything out of that range, like WOT is impossible without a wideband.

Gotcha.

[Blizzard242]

Re: Potential problem? (flutters at startup)

I used to tune a 6bolt gst, adjusting timing and fuel using knock.

lol, that sounds a little bit risky. Not to mention you could be running pig rich like that and see no knock but never really be able to tell. It's just that, a wideband is an awesome tool that should not be overlooked due to the fact that they can make tuning exponentially easier, faster, and safer for your car. You can start on the rich side and lean it up rather than the other way around which can be destructive.

Who was it.. I think viper or someone blew their motor due to knock that the ECM didn't see. I would just never trust tuning to my knock sensors.

[Red&Black_Attack]

Re: Potential problem? (flutters at startup)

Now it does this at 3/4 to WOT from a stop. What is going wrong?

I tried cleaning the maf but it didnt fix the problem. No codes either. It did change how it was doing it but its still hesitating getting up to speed.

I used maf cleaner btw. It did say to let dry before running it but wasnt sure how long it needed. It seemed dry, Maybe I just havnt gave it enough time to dry?

Thoughts? I have no idea whats going on.

[Blizzard242]

Re: Potential problem? (flutters at startup)

Hey, do you have your MAF screen still installed or have you removed it?