How can I tell if hesitation is fuel or ignition related?

[kc92awd]

my car drives okay at light throttle. If I give it much gas, it bogs and stutters. The more I push on the gas pedal, the slower it gets.

I replaced the plugs and wires and it didn't help. I was about to replace the coils but after seeing the price I think I should make sure before I keep throwing parts at it.

Is there a good way I can narrow it down to either being weak spark or a fuel problem? Car idles fine, so I need to diagnose while driving.

 

[JDNSBR]

my car drives okay at light throttle. If I give it much gas, it bogs and stutters. The more I push on the gas pedal, the slower it gets.

I replaced the plugs and wires and it didn't help. I was about to replace the coils but after seeing the price I think I should make sure before I keep throwing parts at it.

Is there a good way I can narrow it down to either being weak spark or a fuel problem? Car idles fine, so I need to diagnose while driving.

What are you running for fuel mods? Need a little more info. I checked your mods list and it didn't tell me much.

 

[1hottalon]

hey did you replace your fuel filter when you changed your plugs and wires. It might be plugged.

 

[kc92awd]

What are you running for fuel mods? Need a little more info. I checked your mods list and it didn't tell me much.

Sorry. This car is completely stock. That modlist is from my old Talon.

 

[kc92awd]

hey did you replace your fuel filter when you changed your plugs and wires. It might be plugged.

I changed the fuel filter about a year ago.

 

[akdsmer]

Watching your O2 sensor voltage will tell you if you are driving it lean. Anything under 300mV is LEAN (although everyone can argue where if should be under a light load ). If it is running lean, you'll need to check fuel pressure/volume, PCM inputs (MAF, TPS, IDLE switch) and the like.

Using a DATA logger would be a good tool here.

You should also check the Idle switch. I've seen them make the car cut-out (which isn't exactly your symptom- but's its easy) when it was failing. Disconnecting it will tell the computer your off-idle and should remedy the symptoms.

It also would be good to check backpressure, in case your exhaust system is restricted. Dropping the down-pipe and driving it to see if it improves would be a way without using a pressure gauge (which I recommend. Anything over 2.5 PSI under load is the technical limit, but I rarely see over 1.5 PSI under normal driving)

Most likely not an ignition problem, since that would be less of a bog and more of a shudder/jerkiness

 

[Omegax3000Vr4]

A boost leak test might be a good idea.