Been digging on my 1993 atx for a bit now.. Still nothing.. Help

[fordguru]

The Haynes manual has been somewhat helpful but i need Voltage specs now per sensor or PCM pins I am thinking. To the best of my ability i have ruled out these things. Clogged cats(installed new) coil pack(new)DIS (new) spark plugs new and all the old lugs look the same. MAF/TPS/ATS/CTS Voltage "seems" to be in spec there too. Did diggng on Camshaft sensor found nothing as well as the Cankshaft sensor. I have Ohmed out from PCM the injectors all Ohm out at 15.2. Fuel pressure is 36 to 41 depending on load. IDEAS?

This vehicle cranks up and runs. Is down on power and has a miss that gets worse under load. TPS i never seen 5 volts i only got 3 in garage throttling it but it came up smooth from .99v to 3+volts.. MAF was smooth too.. At a loss.. I havent had anyone diagnose a vehicle for me in years. I may be about to carry this one somewhere with better diagnostics. Help me if you can!

Next up is to check Spark plug wires wich are only 3 years old.


Should i fork out for Chiltons manual? For the exact Voltage spec per sensor.. i miss my Pro service Tech..

Thanks

Jason

 

[SHOdded]

Since you are not looking at an FSM, the first thing that comes to mind is: are the plug wires routed correctly? I believe that some of the aftermarket manuals have an error in that info.

 

[fordguru]

Thanks for the reply! Unfortunatly this vehicle was running good before i worked on it. So i can rule that out. now i did change the plugs but at that poit it was running the same before and after. Going to remember the thing about wrong order in certain places just n case.
Thanks

 

[SHOdded]

Since the TPS is another frequent malcontent on these engines, I looked around re: the voltage and found this thread:
http://www.shoforum.com/index.php?threads/tps-adjustment.27779/

Voltage range should be somewhere around 0.6-4.5V +/- 0.15V if it is operating correctly.

 

[fordguru]

Great thread! Good reading either way. I just confirmed the TPS is within spec. Going to go back over the simple stuff again. I have a couple free hours today to give it. Wish me luck.. lol

 

[SHOdded]

Luck definitely helps with the SHO

 

[rubydist]

I didn't notice anything about codes in this thread. Are you telling us that there are no codes, or have you just jumped into the "let's change stuff" mode without reading codes?

 

[kevinspann]

First, unplug the MAF and see how it runs. Runs fine? Replacing the MAF usually does the trick.

Second thing I would check is the timing to verify that it is correct.

 

[fordguru]

I didn't notice anything about codes in this thread. Are you telling us that there are no codes, or have you just jumped into the "let's change stuff" mode without reading codes?

No codes .. That's why I am attempting to verify each sensor for voltage specs.

 

[fordguru]

First, unplug the MAF and see how it runs. Runs fine? Replacing the MAF usually does the trick.

Second thing I would check is the timing to verify that it is correct.

I am fairly certain the MAF is working properly. It is within specs on voltage on RPM sweep. As far as engine timing I know this is not an issue because both cylinders have the similar cranking cylinder pressure.

Thanks for input guys

 

[zoomlater]

I had a stumble situation with no codes on a 95 MTX. Is the stumble when you first step on the gas from 1500 to 2500 RPM. Did you check the fuel pressure? The pressure regulator failed on my car and was twice the number is should have been. I was reading on the forum that the engine was stumbling since there was too much fuel going into the engine. Changing the fuel pressure regulator and spark plug wires cleared up 95 percent of the issues. The plug wires were non stock and I'm guessing the plugs the previous owner probably was non stock as well.

 

[rubydist]

did you run the key on engine running test? or just pull stored codes? it is important to run the koer test with your symptoms.