95 GTS skips at part throttle when cold...HELP?!?!?!

[tk_5.0]

First . The car has edelbrock performer heads, e303 cam, headers and an offroad x pipe. I have replaced the tps sensor and PCM. I cleaned the mass air sensor and idle air control.Its got new msd coil, plugwires, cap, and rotor. Its got new NGK plugs.

Now to the problem.

When the car is cool it skips very bad. It clears up "mostly" when the engine reaches operating temp but it skips sometimes too when its warm.
When i press the throttle to the floor. It comes completely out of the miss and runs great.

I tried to pull the codes from the computer but got some garbage think maybe i didnt do the test right. I got a code for the 4x4 switch was broke. I know thats not right. Some help doing the computer test will help to.

Thanks

 

[hotcobra03]

Posted via Mobile Device

 

[TrueBlue95GT]

Connect the jumper wire, turn the key to the "on" position without starting. Wait for it to go through the test and then the check engine light will start blinking. I believe the first blink is alone and then you start counting.

 

[Chythar]

Make sure you're reading from the data connectors behind the passenger shock tower in the engine compartment, not the data connector under the dash on the driver's side. The dash connector is for the V6 cars only; Ford tried to save money on inventory by using the same dash on all 94-95 Mustangs. On the GT & Cobra, the dash connector is not hooked up.

Use your code reader to run the KOEO and KOER tests, and report any codes you get. If you have the right code reader, its manual should tell you how to run those tests.

 

[DDSTANG94]

its probley ur ECT , i replaced mine and it felt like new the first cold morning i drove it, and the computer never showed a code that the ect was bad, but it for sure was, it was night and day

 

[HISSIN50]

Agreed with getting those codes checked before throwing parts at it.

Good luck.

 

[tk_5.0]

i ordered a code reader with a digital display. Now there will be no reason i mess up counting the cel blinks. it was only 25 bucks and came with free shipping off amazon.com . The ECT was the next thing i was going to replace but i figured i might get the trouble codes first.

 

[desertcox05]

i've also read that our cars don't like the platinium plugs. ( i'm assuming the ngk's are platinium)

 

[tk_5.0]

there just the standard ngks. One more day and i will see what trouble codes are in the computer.

 

[juiced_94gt]

Hey my car was doing the SAME thing!!! but it's built and tuned..... Undo ur battery for like 30 mins and undo ur 02 sensors, if this makes it run fine after that then you have a slight exhaust leak that ur 02 sensors is picking up, I was supposed to go for a retune but the other day I undid the battery again and connected the sensors back up and it ran fine, fixed itself I guess but im still gonna have it tuned again anyways. Try it, it might be the o2 sensors if ur motor is stock or have a leak at the collector or flange that you dont know about. and IT'S OK TO DRIVE WITHOUT o2 SENSORS EVEN WITH THE CHECK ENGINE LIGHT ON.

 

[tk_5.0]

well the trouble codes are in...
177
327
542
543

If anyone knows where the fuel pump secondary circuit is help me out.

 

[HISSIN50]

The FP secondary circuit is the power from the relay (in the CCRM) to the FP itself. You'd need a way to be sure the FP relay isnt opening while you drive. You could tap on the CCRM with your hand while it idles, while you have a test light connected, to see if you can make the test light go out. Otherwise, it can be tough to narrow down an intermittant issue, as this appears to be.

 

[BlackVert]

mine was the other way around .... ok when cold, misfiring after warmed up.

it was a couple of bad spark plug wires ... damn equal length headers!

 

[tk_5.0]

well after getting those trouble codes. I took a stab at the ECT it was only 20 dollars but it was 20 dollars wasted. There has been no change in how the car runs. Now im wondering if its the EGR or one of those fuel pump codes. This is getting difficult to deal with. There may be a 95 GTS on the market soon.