1G Breaks up, Sputtering Issue

[TurboChrged93]

This is how I feel.

Anywho....

Been tinkering with this car for a few days. Can't seem to figure this one out.

1992 Eagle Talon TSi FWD
Mods needed to know: Walbro 255

Just finished istalling a new engine in this car and was driven for about 3 days with no issues. Now the car wants to break up under any load and will break up upon free revving after a few revs. Once it idles again for about 30 seconds it will clear up and idle like a champ. The car will idle normally all day without a problem. But free rev it a few times and it will act as though it's running on 3 cylinders. Let it idle again for a few seconds and it clears up once again.

Parts replaced: Cam angle sensor, fuel pressure regulator, MAF, coil pack, transistor, o2 sensor, ecu, fuel pump relay.

After replacing all of these parts, it does take a few more free revs for it to begin it's sputter/misfire again but hands down it still does do it.

Inspected: Boost Leak Test, Compression Test, Base Ignition Timing, Engine Timing, Injector Resistor Box

Logger: All parameters in the datalogger look normal except the o2 sensor which was then replaced.

Working with these cars for about 5 years and this is my first headache! Won't be my last. Ideas?

Thanks...

 

[Froyd79]

How about the spark plugs? gap could be way off or not consistent. Also take off the plug wires and really inspect them. I have seen some crazy stuff in my day! A compression test would be a great place to get some base numbers. And Maybe you need to adjust CAS after everything checks out.

 

[laserspeeddemon]

What do you mean "Break up"

Do you mean like spitting fuel or misfiring or just dies?