HELP! Hesitation / bucking

[xxShaneOmac]

Well I have changed my Fuel Filter, New plugs gapped to .040 New wires and have used fuel clearer additive.

I can drive my car great for appx 20 mins, then after that when Im like at 5% throttle my car will bog hesitate and buck back and forth like no gas or air.

I can be slowing down or keeping constant speed and it will do it.

Soon as I apply more gas 20% throttle it will go away and I can drive.
But I cant drive like that through town all day I need to slow down and ease on and off the throttle.

Soon as I let off the gas its gone, Soon as I push in the clutch its gone and soon as I give more gas its gone.

What can cause this? what should I check.

Fuel Pump
Fuel Injectors
Intake
MAF

what?!

Thanks

[1993 2.0L 4G63 NT no mod's]

 

[siceclipse]

regap plugs to .028-.032" (correct factory gap)
what plugs did you buy?

 

[95blackGsTurbo]

NGK BPR6ES for stock cars and BPR7ES for modified ones. Gapped to .028". .040" is WAY to much.

 

[xxraptor660xx]

Well I have changed my Fuel Filter, New plugs gapped to .040

What were you thinking??

Gap them to .028-.032, as mentioned above.

 

[My1GLaser]

Besides the definite gap correction you need to make, the plug wires could be a problem if they are the Advance or Autozone brand. I installed a set in the past on a different car that were worse than the 150,000 mile wires I was replacing. They misfired like hell right out of the box. Crap, crap, crap! Get NGK wires if you haven't already. Good luck.

 

[95blackGsTurbo]

For stock ignition systems you don't need any fancy wire. I order wires from everywhere at work, Autozone, CSK, Carquest, Napa...whoever has them for the cheapest. Crossfiring can be avoided by crossing the wires when routing them back to the coil.

 

[xxShaneOmac]

I have a NT
and on my hood it says .039-.044

Can someone Check this for me.

 

[95blackGsTurbo]

Then change your profile, it says you have a GSX. .040" is right.

 

[xxShaneOmac]

Then change your profile, it says you have a GSX. .040" is right.

I have a GSX,
But if you read the whole post you would have seen

[1993 2.0L 4G63 NT no mod's]

I have a DD and this is a question for that DD as I stated.

Anyway back to the topic.
When my car is colder I have abouslutly no problems at all.

Blah this is getting old.
Should I pay 60 dollars to have jiffy lube inject fuel cleaner though my pvc vaulve or something? See If that works?

No CEL

Just flushed the raidator and fresh oil / filter change as well.

 

[xxShaneOmac]

what plugs did you buy?

NGK BR6PES or w/e with Bosh Premium 7.5mm wires.

 

[V8notENUF]

Sounds to me like it could be throttle body related. When ever you close or open the throttle, problems gone. When your vehicle is cold, no problem. But once the engine is warm, the problem is back. How long has this been happening?

 

[V8notENUF]

Any possibilty it could have a leak between the throttle body and intake manifold?

 

[jshuman]

I am wondering if it is a TPS related issue. I had a similar issue which was a combination of an improperly adjusted tps and faulty idle switch. Those may be a couple things you should check. Also make sure your throttle plate isn't sticking.

 

[xxShaneOmac]

I think my plate could be sticking but its only once my car warms up.


Cold car - no problem
Warm car - appx 20 mins of driving it shows.
Coasting - no problem
Clutch in - no problem
>5% Throttle - no problem
<5% throttle - problem!

Light throttle chokes the car.

Sounds like a fuel problem
Sounds like a faulty MAF
Sounds like TPS
Sounds like Idle Swtich
Sounds like Im going crazy!

Anyway to pinpoint this?

 

[jshuman]

I wish I could pin point this for you. I would go through from the most simple to the most complicated and test any possibility. I would get the car warmed up to where the problem starts to occur. Pop the hood and have a friend rev it a couple times. Then manually try to move the thottle plate by rotating the linkage on the throttle body. If you can close it further then it is sticking. I would try this first since it is a pretty simple test.

 

[andymac40330]

this may be irrelevant, and may sound stupid, but have you checked your o2 sensors? I had the EXACT same problem on my 300z and after i tried EVERYTHING, it turned out to be my o2 sensor. Like i said, may or (probably) may not be the problem, but thats exactly how mine acted when that happened.

 

[big_d]

Do you by chance have a logger to test to o2, this would tell you if it is cycling correctly, and is your maf sensor plugged in? big_d

 

[xxShaneOmac]

MAF Sensor is plugged in.
This is my non turbo DD so no loggers or anything.

This only happens when the car is warm.
When its cold I cannot get this to happen at all.

Some kind of intermitted problem in my TPS or MAF sensor?