92 Mustang Popping Hesitation

[Rocky Rodriquez]

Need help guys I've had this car for 2 years dump crazy $$$ still popping out intake hesitation cold and warm things I've changed
New motor bought a turn key throttle body to oil pan
Map sensor
Ford racing multi port racing harness
New o2s
New coil
Mass came with motor
Acts just like it did with old motor just worst

 

[Mustang5L5]

What is it? Year? Have you run the engine codes?

 

[mikestang63]

popping out the intake is usually a valve or timing problem

 

[Rocky Rodriquez]

I don't think it can be a valve the old motor did the exact same thing its a 92 5.0

 

[Rocky Rodriquez]

And it sometimes drivers great than starts popping. Drove it today on the interstate and running good than started popping and loosing power slowing down I have to floor it to get to go, but sometimes it runs great

 

[Rocky Rodriquez]

And it sometimes drivers great than starts popping. Drove it today on the interstate and running good than started popping and loosing power slowing down I have to floor it to get to go, but sometimes it runs great. The fuel pressure is at 34 disconnected and plugged 29 connected I've never had the tank dropped that's about the only thing not new

 

[Rocky Rodriquez]

It's a mustang sorry forgot to mention that

 

[General karthief]

Oh, and it's modified.
I'm going to ask, did you replace the engine because of the poping?

 

[Rocky Rodriquez]

Well it was the planned either way but the car has always did it since I bought it, but acts the same with the new engine but sometimes runs great

 

[General karthief]

Well we can rule out the engine, I looks to good to be pop'n.
Have you run the codes?
Fuel pressure looks a little low, I think it should be 40+ unpluged and around 30 to 35 plugged in.
Check fuel pressure, give it a good quick rev with vac line attached and see if it goes up.

 

[Rocky Rodriquez]

Ok did that it accurately goes down a little bit I'm thinking it's gotta be somewhere in the fuel I got a new tank I ordered awhile back. Think I'm going to order a pump and sending unit since my gauge is off a bit. Thank y'all for any help this car has been such a pain in the butt

 

[General karthief]

No, a pain in the butt is sitting on a tack, a mustang is kinda like a female, you love it so you put up it, or you hate it and trade it for prius, just remember


If it has tits or tires it gonna give you trouble, handle it.

 

[jrichker]

Dump codes sticky

Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. Codes may be present even if the CEL (Check Engine Light) isn’t on. You don’t need a code reader or scanner – all you need is a paper clip, or if your lady friend has a hair pin, that will do the job.
I highly suggest that you read it and follow the instructions to dump the codes. http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/

 

[Rocky Rodriquez]

Maybe I should just go carb if this don't work
As far as checking codes no haven't since all new harness

 

[General karthief]

Yea just give up and go carb, geez,
Why don't you give us an accurate run down of what you started with and what you've done to it, sounds like your just not diagnosing the problem and/or throwing parts at it hoping to fix it.
I have found efi takes some patience and finesse
Changing to a carb will likely not fix your problem.

 

[Black1987]

Ok did that it accurately goes down a little bit I'm thinking it's gotta be somewhere in the fuel I got a new tank I ordered awhile back. Think I'm going to order a pump and sending unit since my gauge is off a bit. Thank y'all for any help this car has been such a pain in the butt

Few things:

1.Pull the codes

2. You mentioned new harnesses, did you by chance change your O2 sensor harness? Like for going long tubes to shorties or vice versa? A mismatch auto/manual O2 harness caused a similar problem on mine.

3. Is the Maf matched to injectors?

4. Oh pull the codes

5. Inspect for a loose rocker... if it is loose it can not close the valves properly allowing popping thru the intake.

6. Inspect the mass air sensor and clean it with mass air cleaner.

7. When all else fails pull the codes and we can help.

Best of luck

 

[aztecgwynn]

Mine did same thing popping, stuttering, hesitation, loss in power. It even left me stranded on side of rd. It would defiantly start but would not run under load. Mine ended up being a bad and old distributor. Mechanic took old ignition module and switched it to new distributor! That's it problem solved, good luck hope that helps

 

[jrichker]

Maybe I should just go carb if this don't work
As far as checking codes no haven't since all new harness

Very bad idea.... if you cannot follow directions and guidance given here you'll do more damage with a poorly done carb conversion....

The computer's diagnostic codes point to what's failing, and can greatly help you find and fix whatever problems the engine has.

 

[Rocky Rodriquez]

Very bad idea.... if you cannot follow directions and guidance given here you'll do more damage with a poorly done carb conversion....

The computer's diagnostic codes point to what's failing, and can greatly help you find and fix whatever problems the engine has.

 

[Rocky Rodriquez]

Gonna get codes today and let y'all know not going carb got to much in the harness it's a complete racing harness to o2 sensors to computer i have no salt and pepper shakers either