small rpm surge while driving

[Bob Lob Law]

Like this? Can feel a slight surge when it does it.



I don't know what it was doing, but it has stopped since getting tuned.

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[PoCoBob]

Every year I run a bottle of cleaner through the fuel system during first fill up.

Earlier this year my car idled so bad it would stall at a red light. I put a can of fuel injector cleaner in the gas a couple times and it didn't help at all. Then I remembered these car have two separate fuel systems that are not usually working at the same time, so how would you know which system the injector cleaner actually went though. From what I understand most injector cleaners don't mix with the gas, they're heavier than gas so they move to the bottom of the tank and go through the engine all at once. That's why you only have to drive a few blocks before you notice the difference. I mentioned Seafoam in my first reply because it does mix with the gas and it takes longer to feel any difference it's making. But using it will insure that some of the cleaner will go through both fuel systems. Since I did that my car has been running great.

 

[blankman]

Like this? Can feel a slight surge when it does it.



I don't know what it was doing, but it has stopped since getting tuned.

Yes and no. If I hold that rev it doesnt happen. It only happens when its at a slight load while driving.

 

[blankman]

Earlier this year my car idled so bad it would stall at a red light. I put a can of fuel injector cleaner in the gas a couple times and it didn't help at all. Then I remembered these car have two separate fuel systems that are not usually working at the same time, so how would you know which system the injector cleaner actually went though. From what I understand most injector cleaners don't mix with the gas, they're heavier than gas so they move to the bottom of the tank and go through the engine all at once. That's why you only have to drive a few blocks before you notice the difference. I mentioned Seafoam in my first reply because it does mix with the gas and it takes longer to feel any difference it's making. But using it will insure that some of the cleaner will go through both fuel systems. Since I did that my car has been running great.

Ill admit right away, these motors are way different than what im used to in the pushrod world. So its obviously a very different world for me. Going from pushrod v8s and MT to a DI v8 ATM is way different than what im used to working on.

 

[robvas]

Earlier this year my car idled so bad it would stall at a red light. I put a can of fuel injector cleaner in the gas a couple times and it didn't help at all. Then I remembered these car have two separate fuel systems that are not usually working at the same time, so how would you know which system the injector cleaner actually went though. From what I understand most injector cleaners don't mix with the gas, they're heavier than gas so they move to the bottom of the tank and go through the engine all at once. That's why you only have to drive a few blocks before you notice the difference. I mentioned Seafoam in my first reply because it does mix with the gas and it takes longer to feel any difference it's making. But using it will insure that some of the cleaner will go through both fuel systems. Since I did that my car has been running great.

Where did you hear injector cleaner sinks to the bottom of the tank?

Seafoam doesn't clean injectors very well

 

[PoCoBob]

Where did you hear injector cleaner sinks to the bottom of the tank?

Seafoam doesn't clean injectors very well

Honestly I don't remember were I heard it, but it does make some sense since it works almost immediately.

I've had good luck with Seafoam although I haven't needed to use it very often.

 

[robvas]

Honestly I don't remember were I heard it, but it does make some sense since it works almost immediately.

I've had good luck with Seafoam although I haven't needed to use it very often.

The psychological effect of dumping a can of shit in your car...

Seafoam Motor Treatment (the can you can pour in your gas, oil, cylinder, wiper fluid reservoir...) doesn't even have cleaners like PEA. Even their fuel injector cleaner doesn't have it.

 

[Gregs24]

That is correct. Stock auto 10spd. Thats one of the things I read from Google about the TCC slipping or trying to find the best gear. Thats what advised me to try it in the different modes and sport plus to see if it happens in those as well.

That will be it then. The torque convertor / multiplier will unlock and use more revs at the same speed when a small additional input is made, especially at lower speeds

 

[PoCoBob]

The psychological effect of dumping a can of shit in your car...

Seriously dude? I already posted the car would stall when stopped at a red light and after putting the Seafoam in the gas it went back to idling smoothly. But hey, you seem to know more about my car then I do so thanks for that insightful post.

 

[robvas]

Seriously dude? I already posted the car would stall when stopped at a red light and after putting the Seafoam in the gas it went back to idling smoothly. But hey, you seem to know more about my car then I do so thanks for that insightful post.

Just shows your problem wasn't dirty fuel injectors because seafoam doesn't clean fuel injectors.

Not to mention your post about the cleaner not going through both fuel systems making no sense at all. There's only one pump in the tank that sends fuel to both DI and PI systems

 

[Goterr0r]

Do you have an aftermarket grille? There have been reports of similar surging with certain aftermarket grilles that really open up the front of the car.

 

[Gregs24]

Look at the speedo - it never moves as the revs rise. It can only be the torque convertor unlocking.

 

[K4fxd]

You should be able to log with forscan, log tcc and mark points where you feel the surge. The stock tune has several things happening at the same time, like the imrc opens and/or closes, the exhaust cam moves 30 degrees, the timing gets pulled and the torque converter locks/unlocks all at the same time at certain speed and load conditions.

Most likely this is what you are feeling. Log the channels I listed along with the normal channels.

 

[blankman]

Do you have an aftermarket grille? There have been reports of similar surging with certain aftermarket grilles that really open up the front of the car.

I do not, stock grille.

Look at the speedo - it never moves as the revs rise. It can only be the torque convertor unlocking.

Yeah it doesnt fluctuate at all when the small surge happens.

Considering it happens in every gear I would think thats not normal operation?

You should be able to log with forscan, log tcc and mark points where you feel the surge. The stock tune has several things happening at the same time, like the imrc opens and/or closes, the exhaust cam moves 30 degrees, the timing gets pulled and the torque converter locks/unlocks all at the same time at certain speed and load conditions.

Most likely this is what you are feeling. Log the channels I listed along with the normal channels.

Ok, Roger that. This weekend I should have time to get it done so I'll post some than. Just a forethought also, I never did change my tire diameter for the new wheels. I'll get that sorted before I start logging and see if that does anything also.

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