New thread for my low speed RPM issues

[camelman]

The exhaust side didn't seem to be firing at all. I'll check that again.

 

[camelman]

Guess what has two thumbs and forgot to plug in the exhaust-side coil pack!? THIS GUY!!!

I just plugged it in and the truck is much smoother now. I'll drive it around today and see if it is fixed.

 

[camelman]

The problem still exists. I replaced the CPS today and repaired torn insulation on the CPS harness, and still no improvement. The ABS light does not come on any more, and I can find no evidence of vacuum leaks.

The issue is still that the engine misses at idle about 25% of the time. The engine will hesitate sometimes when I try to accelerate, and has poor low RPM drivability.

Any thoughts?

 

[camelman]

I blew a power steering line I don't feel like dealing with, so the truck is at a shop. Hopefully they can figure it out.

 

[camelman]

The shop had no idea what was wrong and didn't find any trouble codes. I messed around with it again today, and found that pushing hard on the plugs where they snap onto the coil packs dramatically reduced misfires. I also noticed the wires didn't fit into the coil packs very well. I ordered a warranty replacement set through O'Reilly. Will report back in a few days on the result of new wires.

 

[camelman]

I replaced the plug wires today with a better set of Motorcraft wires. This set has the handles for the rear three plugs on the intake side... the previous set did not. This set seems better made too, and the truck runs marginally better. I found out my cat is broken internally and the core is rattling around in the shell. I imagine a broken cat will cause a rough idle on its own. I'm ready to stop with the fixing and just drive. Maybe find a replacement cat later.

 

[XLTsplash]

A cat that's coming apart isn't good. There are good deals for bolt in cats on ebay.
http://www.ebay.com/itm/381000356821?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[camelman]

Thanks, I think a replacement cat my be in the near future. HOWEVER... I bought a bluetooth OBD2 unit and installed Torque on my spare tablet. It is such a cool app!

A couple things I noticed with the Torque app:
~ Engine temp is fairly steady at 195-202F, but occasionally drops to 140F or -20F for a split second. Strange?!
~ sub 190F idle: 800... over 195F idle: 720. Cold when sitting still after warming up, warm whenever moving or after stopping. I saw the idle drop to 0 momentarily when the engine stumbled once.
~ fuel mileage is back up to 25+mpg. I think the EGR valve was the biggest culprit
~ the strange idle stumble and low RPM issues are still there
~ Fuel trim is below 12.

Camelman

 

[tomw]

"I saw the idle drop to 0 momentarily when the engine stumbled once."

I would be checking the ignition system as I think dropping to zero indicates loss of signal, especially if you have an intermittent miss. This thread is so long I have lost track of what it started out to be about...
tom

 

[XLTsplash]

The fuel trim when you have the misfire also indicates ignition. Sometimes a signal loss for a split second could just be with the OBD2 reader, it's possible it could be with the truck itself if you see the rpm drop to 0 every time you feel the misfire. Does your reader show a misfire count ? Can you check the PIDs for the crank and cam sensor inputs with your reader ?

 

[camelman]

I either cannot read misfires, or it is not recording them.

Also: Fuel trim varies between -.5 and 3.0 while idling.

I changed the coolant temp sensor (engine side, not gauge side) today and checked the wiring for the CKP and CTS. All wiring looked good. I also checked all engine connections I could find (had to unbolt a couple), and they all looked clean.

I tried to access the Cam Position Sensor, but could only reach my hand around the power steering pump bracket. The CPS is covered in oil, but not sure where it is coming from. The engine runs slightly worse after prodding the CPS, and it has a slight surge going uphill at low RPM in first gear now. Timing at idle varies between 8 degrees and 10.5 degrees BTDC, but will also hang out at 20-31 degrees BTDC anywhere from idle to 1500 RPM.

The idle indicator only showed 0rpm once. I'll look for PID reading options for the CKP and CPS.

Not sure what to do now.

 

[XLTsplash]

You can clean around the CPS with brake cleaner so that you can try and pin point what is leaking. Checking the CPS and CKP PIDs is a good idea. The front cover on my 97 2.3L was all grease, it didn't drip oil. Mine was the front cover seal that was leaking slightly.

 

[camelman]

I pulled the power steering pump/bracket off, and cleaned the area. It was just power steering fluid from the pump failure. Since I was in there I replaced the CPS. The truck ran a little smoother after doing so.

I replaced the throttle position sensor afterwards, which made the truck MUCH more drivable. The stutter at low RPM is almost 100% gone, the idle is steadier, and power comes on MUCH more smoothly.

The following issues have now shown up. Engine idle hangs and then comes down slowly. Idle is silky smooth when it first comes down, but gets rougher after 30 seconds of sitting at idle. Any ideas?

I also get an oil leak that hits the exhaust only when going uphill. Any ideas? I replaced the valve cover gasket and cannot find an oil leak when I feel around it after driving.

 

[XLTsplash]

Have you pulled the throttle body off, cleaned it and checked the throttle shaft for looseness or binding ? What part of the exhaust is the oil dripping onto ? You can also disconnect the battery so the PCM will have to relearn with the new parts you've installed.

 

[camelman]

Woohoo! I found a vacuum leak that I must have created during the last repair. The engine runs like a champ now (except the ABS light is back on again). I'll clean the engine and look for the oil leak this weekend, but I think I'm mostly done with this engine repair.

I'm not sure what's up with the ABS light yet, but I'll start with a brake fluid flush... it's the original fluid!!!

Thanks to everyone for the help.