Hi all. My ETC has close to 200,000 miles on it and is running rough.

Things done recently: Full tuneup with original type plugs, wires, PCV, etc. New fuel and air filters and new oxygen sensors. It ran like a rocket after everything was changed. Like new, actually.

Cold idle was still an issue though. I could never figure out why it idled roughly for a few minutes when first started. The engine would usually run rough for a few minutes until it smoothed out (you could hear the difference in the exhaust). Eventually, it would even out and drive smoothly so I let that go. A short time ago, I did experience a miss in the engine but after putting Techron fuel injector cleaner in, it smoothed out and ran well once again.

Then, it started running rough while driving...

The present trouble: Same rough idle at cold start. When I would accelerate in traffic, the car would hesitate slightly until I backed off of the peddle a bit. Then, the engine responded alright. The hesitation problem persisted but the car was still driveable. This past week when I drove it, right off it definitely had a miss of some type because it sputtered away as I drove (I actually had to turn around and get another vehicle because it was running so roughly). At idle, the car continues to sputter and the exhaust smells rich.

I cleaned the throttle body and EGR valve, but no change. I did pull the front plugs (not the back, yet) and the #4 plug was wet and the others were dry. Otherwise, they looked alright.

Could this be a fuel pressure problem, coil, or fuel injector problem? If so, does anyone have any suggestions on how to tell if a coil or fuel injector is bad, or how to check the fuel pressure?

Any suggestions you all may have on what may be going on, I would surely appreciate. Thank you.

Sean

Check the fuel pressure. Get a fuel pressure gauge and put it on the service port on the fuel rail. Check for a leaky FPR. When you did the tune up, did you replace the cap and rotor?

Thanks, Ranger. Being that it's a four-coil distributorless ignition, I didn't know that there was a cap and rotor to replace.

Please help me with my ignorance.

Sean

Oops sorry, I thought it was a 4.9. I should know better. Consider that part a figment of your imagination.

I neglected to mention that there are no codes showing a misfire or anything else, so that adds to the mystery.

If the spark plug was wet its the Ignition coil , my #8 coil went bad last week #3 was still good , so half the coil failed? I had same symptoms sudder/missfire , checked the plugs , noticed plug 8 was wet , swithed a coil , 8 fired up (Dry), went an bought a BWD one up at Advanced Auto for 24$ . Problem solved 48069

Thanks for the info on the coil. I attempted to open your attachment, but all that came up was... "Invalid Attachment specified."

Its a diagram for Firing order , I cant find the picture on this forum (were i got it) . It was posted by submariner409 , i searched their posts , but , came up empty

No problem about the attachment. I appreciate your information and will check it out after we thaw out a little here in the Philadelphia area after a big snow fall and low temps.

Thanks again. Sean

Sub has posted it many times. I'm sure if you do a search it will come up.

Hi all. I replaced the 4,1 coil and the car is back to running smooth again. It's amazing that a $25.00 part can make all the difference.

Thanks guys, for taking time out to help me figure out the problem. It's great to be back on the road again!

................Once more, with feeling........copy and put on the shop wall.

Thanks, Sub. Much appreciated.

Here's a fun trick for you to try. Only us OBD-I guys can do this. 93-95. You can override the fuel injectors from the dashboard to see what cylinders are missfiring.

-Go into diagnostics mode and wait for it to get to "PCM?"
-Press the fan up button to go into the PCM menu
-Press the fan down button until you reach "PCM OVERRIDE?"
-Press the fan up button to go into that menu
-Press the fan up button until you reach "PS04" The rpm's should raise and in the small display over the fan button it should say "01" That's the cylinder number.
-Press the cooler (blue) button to disable the fuel injector for that cylinder
-Listen and watch if the rpms change. If they change, then that cylinder is working fine. If there's no change then you know that cylinder is missfiring.
-Press the warmer (red) button to cycle to the next cylinder
-Repeat the last three steps till you've found the all of the cylinders which are missfiring.
-Turn the key off to exit diagnostics mode