Engine wants to go but wont

[ranger690]

Lately while ive been driving, I will give it alot of gas and the engine sounds like it is reving up and want to move but the car just dosent get up and go like it should. I had the problem with chugging ( was told to get new plugs, which im in the process) and am getting it fixed soon but as time has progressed it has lost more and more go power. I bought some maf cleaner, hoping it will do something but any other suggestions as why it is doing this would be helpful.

Thanks,
kyle

 

[TopGunnYFZ]

What car is this on? ATX MTX?

Are the revs there and its just not going or it's not pulling the rpms it should?

 

[ranger690]

its an mtx and it isnt pulling the rpms it should i can bury my foot in the gas and the rpm dosent accelerate quickly it accelerates 1/8 throttle like it does at full

 

[rubydist]

There are a number of issues that could cause those symptoms. Could be tps, dis, coil pack, plugs, wires, etc.

First, check codes and report what you find. Then pull a couple of plug wires off the plug and check for oil in the plug well. Let us know what you find.

 

[ranger690]

i was thinking of cleaning the iac (i think) it is the cylinder thing by the throttle body i read on the shotimes website that if it is clogged that it could be cause for the lack of power and chugging-stuttering that is occuring. I also had my valve cover gaskets replaced because there was oil in the plug wells since then i cleaned them up and no leakage.

 

[LJRuddy]

First clean your maf. After that, I'd measure voltage on your throttle position sensor. After that, I'd check fuel pressure. I doubt its ignition related as every ignition issue I have ever encountered, it also came with some degree of misfire, backfire, rough idle, part throttle or WOT as well.

 

[ranger690]

I cleaned the maf so how do I go about measuring the voltage on my throttle position sensor and checking my fuel pressure? Curiously what would you guess my problem is.


Thanks again

 

[LJRuddy]

I cleaned the maf so how do I go about measuring the voltage on my throttle position sensor and checking my fuel pressure? Curiously what would you guess my problem is.


Thanks again

The few times I have had issues similar to yours - in SHOs as well as other Fords - I found a lack of fuel pressure to be the culprit.

The reason I doubt that you have an ignition problem is because those usually cause obvious symptoms. A bad DIS module, coil, plug, or plug wire will more often than not cause a misfire or something similar. Sure, a few plug wires with extremely high ohm readings could cause a lack of power with no misfire. However, the way you described your issue, I doubt you have bad plug wires as they would have to be so toasted that you would see other ignition-specific symptoms.

How do you check fuel pressure? First go rent a "fuel pressuer gauge" from Advance Auto Parts. Then, locate the fuel pressure gauge fitting on your fuel rail. It is located between the 2 long runners closest to the Idle Air Valve. Here it is, to the left of the upper red circle:

Turn the key on but don't start the engine. The pressure readout should be close to 35psi and the pressure should not be noticeably dropping.

Now start the car. You should see about 39psi at idle.

Blip the throttle quickly to WOT and back to idle. You should see a quick spike to somewhere above 50-55psi. I usually see closer to 60psi. Once the throttle blip is completed, pressure should fall back down to 39-ish psi.

Its probably a good idea to toss in a new fuel filter. They are like 5 bucks at NAPA.

As for checking the throttle position sensor, get a volt meter, turn it to a DC setting and stick the 2 probes into the backside of the top wire and bottom wire. You should see between 4 and 6 volts. A great target voltage would be 5.00 - 5.20 volts.

Now put the probes on the middle wire and the bottom wire. Test results on a good TPS should range from approximately zero volts to approximately 5 volts with no interruption or drop off in voltage. The meter should progress upward as the throttle is opened, and decline as the throttle is closed.

 

[ranger690]

where is the fuel filter located, I do know that the person I bought the car from let it sit for a while and didnt do regular maintenence, like fuel filters, and air cleaners. i have since changed the air filter but forgot about the fuel filter. I am troubleshooting the small possabilities first before I start spnding the big bucks on parts like fuel pump and plug wires.

If when checking my fuel pressure is low what would most likly be the culprit?

Thanks

 

[LJRuddy]

where is the fuel filter located, I do know that the person I bought the car from let it sit for a while and didnt do regular maintenence, like fuel filters, and air cleaners. i have since changed the air filter but forgot about the fuel filter. I am troubleshooting the small possabilities first before I start spnding the big bucks on parts like fuel pump and plug wires.

If when checking my fuel pressure is low what would most likly be the culprit?

Thanks

The fuel filter is located on the frame rail just in front of the rear wheel well. I can't remember which side but you cant miss it. It looks like a small(er) soup can with 2 (i think) hoses coming out of it. Its a simple 5 minute replacement item and it is very cheap to purchase.

Low fuel pressure means you have a bad fuel pump 99.99% of the time. Its either that, or a bad fuel leak somewhere but I have never seen that issue on any Ford except my Mustang when I forgot to bolt a fuel rail down.

 

[shonuffmine]

fuel filter

the filter is just in front of the passenger side wheel well right next to the gas tank, when ya get it apart and ready to reassemble put your fuel line clips in firrst then push them onto the fuel filter *******,you,ll feel it clickwiggle the thing back in then tighten the clamp,Voila there it is