Mis-firing during accelearation/under load

[grogle]

Hello everyone,

I am driving my second Ranger since 1985. The current Ranger is a 96, 2wd, 4 cyl. with 339,000 miles. (Original engine, 3rd clutch. )

It recently started missing during acceleration and under load. The missing only occurs during the middle of the rpm range for each gear. (manual 5 speed)

I have replaced upstream O2 sensor, MAF sensor, EGR valve, and catalytic converter. Fuel filter was replaced 6 months ago but I am replacing it again this weekend.

Question:

There is a gas leak from the top of the fuel tank when I fill up. (Crack in fuel filler tube?) The engine is giving a code P1443 "EVAP Canister purge valve mechanical fault or VMV fault condition". Could a leak in the fuel system like this cause the misfiring during acceleration?

Thanks,

Greg

[Lee_T413]

im not 100% sure to if the evap system will cause a miss, but i do know that this had happened to my 4.0, it was a bad spark plug wire. try checking your ignition sources

[grogle]

Thanks for the feedback.

After much reading on this forum I am becoming more suspicious of a bad plug wire/s. Even though they were replaced a few months ago that may be the problem. I had a local shop replace them and I'm not sure of the quality of the wires they used.

[carsdlt]

Had a similar problem with my '99 - also pinging undeer load. Turned out to be the exhaust side coil breaking down at high RPM - replaced both coils & problem solved. If yours have never been replaced, at 300+ miles, they are way past due. Good luck.

[thelonerang3r]

Can someone explain what "pinging" is for me? My '96 runs rough at about 2000 rpm's. I've got the same EVAP code (P1443), have never replaced the coil packs, and this didn't start till about a week after I changed plugs and wires. It does run much worse when it's raining or extremely humid.

[redneckranger69]

i had this problem in my 83 ranger. it turned out to be a lean pop out of the carb. my fuel filter was clogged, my fuild pump was going out.

[sheltonfilms]

Problems with EVAP usually never cause a drivability issue. I've seen them cause a car to take a few seconds longer to start, but that was it.

With most misfire issues it comes down to ignition. Always use motorcraft plugs in these engines, they really don't like anything else. Also go with a decent set of wires, I go with Borg Warner wires, a little pricey but they have a lifetime warranty. If you do replace your plugs and wires make sure to use anti-seize on the plugs and put some dialectric grease in the boots.

If your engine has the 8 plug set up your problem is most likely coming from the exhaust side. These are the main plugs for the engine. The drivers side (from what I've heard, and read) fire during the exhaust stroke to ignite unburned fuel.

[mt1986]

Check fuel injector connections, if any corrosion in there it will change the values and not squirt the right amount of fuel can cause pinging or worse, good luck