Hi all. I have a '94 XLT 2.3Liter manual transmission with 190,000 miles on it. I just changed the timing belt and now the car is a slug off the line when warm. Could the timing be off? What should the timing be if I hit it with the gun?
I double checked that the marks were aligned when I put the belt back on, but it could have still been off a bit. It starts right up with no problems -- no excessive cranking. It idles fine. It just passed smog check here in CA with no problems.
Also, when the car is cold it runs great. Once it warms up though it is very sluggish to get moving.
Any thoughts??
Thanks,
Walter

 

We need more info. Scan for trouble codes & post up All code Numbers, as they can offer up good clues on where to begin a trouble shoot. If you don't have a scan tool, or code reader, use one of these wiring techniques to extract pending, or set trouble code clues & post All Numbers. www.troublecodes.net/ford/

Was the vehicle wimpy on power at throttle up, Before the timing belt replacement?
Did you also replace the tensioner & idler pully?

With 190K on this puppy, is it up to date on All past & present due scheduled maintenance replacement parts, like PCV valve & its hoses & rubber connection grommets, Upstream/before cat O2 sensor, plugs, wires, air/fuel filters, etc ?

Have you tested fuel pressure & delivery rate over time? EDIT: If you have a scan tool that'll perform a power balance test, have it do that & post the results, as it can flag a suspect cylinder & shorten a trouble shoot.

Some beginning thoughts for consideration, let us know what you find.

 

Hi pawpaw.
I'll have to see if I can get some codes. The cel comes on and goes off.
The car lacked power before timing belt, but now it is pretty bad. I changed the belt tensioner, idler pulley (I managed to brake mine ), t-stat and housing at same time.
I don't think All parts have been replaced -- especially hoses and related items. Is there something (a schematic or something) I can reference to see what hoses should be replaced -- besides the obvious cracked/broken hoses if there are any?
I'll try to test fuel pressure this weekend. I don't have a scan tool to perform a power balance test.
I have changed plugs and wires but can't remember when I last did that. The coil packs have never been replaced -- do those weaken over time?
Walter

 

Ok. I've gotten a few codes. I remember changing the EGR valve pressure sensor, but not the EGR valve itself.
The codes are:
DTC 335
DTC 332

KOER Test
Cylinder 4
DTC 116
DTC 326
DTC 538

I will try to run some more tests when I get home today to see if I can pull some more codes.
Thanks,
Walter

 

Good feedback that the power was wimpy Before the timing belt & hdw replacement.
The 332-335-336 indicate the computer is unhappy with info its being sent about what its trying to have the EGR valve do. Feedback voltage isn't right & the computer isn't sensing any EGR valve movement. Seeing as how the EGR valve itself is rather robust & not usually a problem unless its rusty & physically falling apart, leave it lower down on the suspect list & put the PFE sensor & it's two connecting hoses & electrical connector & wiring higher up on the suspect list, as history has shown they've earned it.
The PFE sensor vacuum & High temp hoses are known to bake out & crack. The orifice beneath the EGR valve where the PFE high temp hose connects is known to clog up with carbon if the engine is using oil, or If its air/fuel mixture is corrupt rich, so the orifice & hose might need cleaning out to open them up, or the hose might be baked out hard & split & if so replace it with the specified High Temp Silicone rubber hose, all so the PFE sensor is getting proper vacuum & exhaust feedback pressure to sense.
Again, the PFE sensor vacuum hose is also known to dryrot & leak & corrupt the PFE sensor feedback voltage to the computer so check it closely.
If all of the hoses are ok, put the PFE sensor on the suspect list, as the early ones were known to fail rather often.

The 538 code says you didn't floor the go pedal quickly or far enough, when instructed to so, thus the computer couldn't measure the voltage change range the TPS sends it as we go at throttle up.

The 116 code says the Engine coolant temp sensor isn't properly sensing engine temp & this can cause the computer to corrupt fuel trim. With your multimeter check the sensor ohms resistance @ cold/hot temp to see if its out of range.

If the PCV valve hasn't been changed its lived Two lifetimes, so is Way past due. Be sure to inspect its rubber hose & grommet for loose fit & dry-rot. As its what can be thought of as a controlled & calculated for vacuum leak, thats downstream of & thus not monitored the MAF sensor, any loose fitting hose, or acting out of the PCV valve internal movement, amounts to a vacuum leak/air flow that the MAF sensor can't detect, so can corrupt fuel trim. The connecting hose likes to crack underneath in its elbow bend, so check it closely. If the valve fits loosely to the engine, replace the grommet.

At this age all rubber hoses & vacuum lines are suspect, so flex & check them closely for cracks or loose fit.

The waste spark ignition system works its plugs & wires Twice as hard, by firing them on Every rotation of the crank shaft, so they need to be designed to take the double work load so the spark gap doesn't quickly open up & make a wimpy spark, thus the specified Motorcraft fine-wire plugs & plug wires are recommended as they've proven to be of good quality & are designed for the double work load & hold up.
The coil-packs are known to crack & arc to ground, unseen underneath, but so far you haven't posted any misfire codes, so leave them off the suspect list for now.

SO, get the Engine coolant temp sensor/the Two wire one, resistance checked out, or replace it.
Get the EGR system checked out & put right so the codes stay cleared.
Replace the PCV valve & hose.
Replace the O2 sensor, if its never been replaced, as they get slow to respond with age, sorta like me!!!!
Check fuel pressure & delivery rate over time. If pressure isn't right, disconnect the vacuum line to the fuel pressure regulator on the fuel rail & if its wet with fuel inside, the regulator diaphragm is bad, so replace the regulator & retest psi & fuel volume over time.
If the fuel filter has never been replaced, do that too.
Post up any more trouble code Numbers.
More thoughts for consideration.

 

I had more time this past weekend and put the scanner on the truck again.
The KOEO test results were again 335 and 332 along with a 111.
KOER test results I got the same 326 and 538 codes, but I also got a 412 code.
I ran a cylinder balance test and it came back that cylinder 5 is weak -- how is that possible on a 4 cylinder engine??
I'll try replacing the temp sensor, pcv and o2 sensor this week and pull some more codes and post back.
Thanks for the help!

 

OK. I've replaced the O2 sensor and coolant temp sensor. I was going to replace the pcv valve, but the auto parts guy gave me the wrong one. Plus, mine looks ok -- it's not all dirty and still rattles. I hit it with some carb cleaner and put it back in.
I tried to check the fuel pressure, but it's not moving the gauge. My setup has 2 hoses -- 1 attaches to the schraeder valve and then connects to the hose with the gauge. I know there is fuel because I can feel and smell it when I undo the 2 hoses from each other. Maybe I'll try borrowing one from the local auto parts store to see if something comes up with theirs.
I'll run the KOEO and KOER tests again to see if what codes I have now after changing those two parts out.
Thanks.

 

Along with fuel pressure, be sure to check the fuel pump flow rate over time, as wimpy flow rate along with below spec fuel pressure, can cause the engine to lay down at throttle up. Flow rate should be something like 1/2pt-i5 seconds pump run time.
Get the right PCV valve & replace it as it's lived close to 2 lifetimes if never replaced. Just because they rattle doesn't mean all is well inside, like a weak spring, worn seat. Also make sure the hose fits tight & the grommet to PCV valve is a good tight/snug fit. Any leak, or corrupt performance by this system amounts to an unmetered vacuum leak, so can mess with fuel trim.
None of this has addressed the EGR system codes, so they'll likely still be there.
When all is said & done, will be interesting to hear how things turn out, so keep us posted on results as you make changes to get scheduled maintenance items up to date..

 

OK. Changed out the PCV valve and changed out the fuel filter. It feels better already. Maybe the filter is why I was so low on power and wasn't getting a fuel pressure reading?? Possibly getting enough fuel to run, but not enough to run well. I'll try to check the fuel pressure again and maybe I'll get a reading this time.
I'll drive it around like this a few days and then pull the codes again. Like you said, I'll probably still have the EGR codes. What do I do about those?
I checked the hoses and all seems well. There are no brittle or cracked hoses.
Thanks again.

 

So the truck is running a bit stronger, but still lacks power -- it has trouble pulling off the line.
I've tried 2 different fuel pressure testers and neither one of them register any fuel pressure. I know fuel is coming out of the rail because I can see, smell and feel it. How can I check the fuel pressure and fuel flow rate on this thing??

 

What kind of fuel pressure testers did you use? Is there a Schrader valve on the fuel rail on a '94 model?

 

Hey tomkat22. Yes, there is a schrader valve on the rail. It is smaller than normal, but I had a hose that fit the smaller Ford schrader valve. No pressure to the gauge though. Maybe there just isn't enough pressure????

 

No pressure on the gauge at all? You should have at least 35-40 showing. When you turn the key to on(not start) you should hear the fuel pump buzz/whine for a couple seconds. If you don't you have a bad fuse,relay,wiring problem or bad fuel pump.

 

No pressure on gauge at all. I've tried 2 different gauge setups. But the truck runs. I drive it everyday. There is fuel at the valve when I pull the gauge hose off.

 

Ok. My fuel pressure is 7 psi. I prime it with the key 3 times and the pressure goes up to 40 but then it loses it almost instantly and settles down at 7 again. What would cause no fuel pressure?