Car sputters under acceleration, why?

[Hybrid4g64Spyde]

I have a 99 Spyder GS w/ DOHC head swap and turbo. It runs like a champ other than when I am accelerating from a stop, it sputters and pops then after a certain RPM it boosts and takes off like a rocket. When the vehicle sputters, the tach flutters up about 500 rpms then come back down to original RPM. Is my TB okay? Should I check something on it? Also, on the freeway under light acceleration it bucks and sputters like it does on the streets, just a little more annoying. It is only at a certain rpm range and under heavy acceleration it is 10X as bad. It is like my engine is getting way too much air or possibly way too much fuel. Help me please!

 

[oldman]

First I would check plugs and wires but most likely you have a boost leak.

http://www.vfaq.com/mods/ICtester.html

 

[joeym4130]

Just another idea to throw out if u didnt do the first easy ones mentioned, big leaks and plugs/wires

o2 sensor. When mine died the car ran horribly until you give it WOT and it doesnt care about o2. Just another idea. Sputtered and ran like butt until changing the sensor

good luck

 

[Hybrid4g64Spyde]

K, I think it might be the o2 sensor. The connector that clips into the small o2 piece of wire is melted because my car got really hot back when I was runnin rich. Should I clip off the connector and hard-wire it in, since it will probably melt again if I replace the connector.

 

[Hybrid4g64Spyde]

K, this is like the 4th time I have posted on here asking for help with my problems. I get more help from my little sister about my problems than I get on the thread. I understand that I am the only person with the 2.4 SOHC to DOHC swap with turbo. I am having o2 problems and sputtering problems. WTF, no one here nice enough to help?

 

[EcliptikIlluzio]

Check the O2. If that connector melted then move it. That is what heat sheilds are for. You can hard wire it but I wouldn't recommend it.

Before checking the O2 do the boost leak and plugs(including plug gap)/wires since that is cheaper.

 

[joeym4130]

Whoah snippy! !

Why dont you fix your o2 before coming back to post again? You said that the wire is melted right? It was kind of hard to understand what melted by your post.

 

[oldman]

K, this is like the 4th time I have posted on here asking for help with my problems. I get more help from my little sister about my problems than I get on the thread. I understand that I am the only person with the 2.4 SOHC to DOHC swap with turbo. I am having o2 problems and sputtering problems. WTF, no one here nice enough to help?

Easy there buddy, read the thread again. You were already given instructions to do a boost leak test, did you do that yet. The last thing you posted was that you think it's the melted o2 wire, and this is how you come back and update to ask for more help?

 

[Hybrid4g64Spyde]

Yes, I did the leak test, sorry for not explaining that earlier. I am going to move my o2 wire to the other side of my motor, since my wire is fairly long. Sorry for being a dick, but this is like the 4th or 5th separate post asking for help on my car. This and the overheating post is the most help I have had in months.

 

[oldman]

Yes, I did the leak test, sorry for not explaining that earlier. I am going to move my o2 wire to the other side of my motor, since my wire is fairly long. Sorry for being a dick, but this is like the 4th or 5th separate post asking for help on my car. This and the overheating post is the most help I have had in months.

Frustration understood. Did you check the plug & wires as well? Maybe this will help http://www.taboospeedshop.com/diagnostics.htm

 

[joeym4130]

you don't happen to have a datalogger do you?

 

[EcliptikIlluzio]

Yes running a log would help to verfiy O2 cycles and whatever else sensor wise and could help locate a problem.

 

[GTM]

K, this is like the 4th time I have posted on here asking for help with my problems.
...
I am having o2 problems and sputtering problems. WTF, no one here nice enough to help?

It's not a matter of someone being "nice enough", it's just that when you do mods it introduces so many possibilities for creating problems. So for every mod you may have to counter with a mod to fix what the first mod did and so on. There is no absolute science here so it's impossible to get straight answers because the cause and effect no longer apply. For every mod comes with a handful of grief when things start behaving badly and the rules of diagnosis can be thrown out the window. If you have read through a few hundred posts you would conclude these are very high maintenance cars since new and then to introduce more problems makes you a slave to the car rather than the car being a slave to you.

This is just so typical of the results which has lead me to the conclusion to never do mods as a professional on a customer's car. The amount of time you spend having to go through everything to see if it was done right already has taken the $10 fix into the $100 waste of time and still not found the problem.

You know you have a problem with the O2 wires so replace or fix, do the obvious first and then go on to the next. Tthe bottom line is while we can sit here and toss out ideas someone has to put their hands on the car. Maybe the low water level in your other thread will magically fix this problem.

Cheers,
GTM

 

[Hybrid4g64Spyde]

Thanks, sir. I did the "burping" of my car last night. Temp still goes above normal, so I am going to replace my t-stat.