SLAYER6708

Hello, I have a 97 f150 4.2l 5 speed that has a problem and I can't figure it out, first I had a misfire in cylinder 5 turned out it was a bad wire, so I got new autolite wires and motorcraft plugs. It started up fine but it felt off, it still had a pretty good shake at idle and its getting worse and now its very hard to start. I've been going over vac lines and everything, I've been reading different forums for about 20 hours and still can't seem to find a solution so I'm asking the gurus where do I go from here? Thanks in advance for your help!

Jbrew

If there's still time swap those auto-lite wires for motorcraft. Otherwise, better check resistance.

Anyway, does the CEL blink once in awhile when driving? It's not lit again right?

Whats you exact warm idle RPM's.

If it's doing this at idle, you need to check your EGR valve. It will idle like shi and run bad at lower rpm's if that valve isn't closing. Higher rpms will be fine.

SLAYER6708

I'm not sure on the rpm, I don't have a gauge, no cel and I will check the egr valve thanks

SLAYER6708

Well I checked the egr I cleaned it and no change what's next?,I have access to a better scanner that can read live data. If I get the scanner what parameters should I look at and what's good and bad? I'm very lost at this point..

Jbrew

Did you suck test the EGR? Yea, that's all you have to do.

DaleLowrie

Have you checked the injectors? They might be worn out and dumping too much or too little fuel. I'd also check the O2 sensors and the catalytic converters too. Is it throwing any codes? And if so, what are they. If you don't have a way to read the computer, take it to an Advance Auto Parts or O'reillys and they'll read it for you for free

SLAYER6708

Its not throwing any codes, how do I test the injectors? Suck test egr no I didn't do that, I was told to unplug the egr if it changes the idle then that's a starting point but it didn't change the idle when I unplugged it. How do you suck test the egr?I do have a code reader but not a fancy one like my brother in law.

Jbrew

What you did is test the EVR. That's good, that means the EVR isn't malfunctioning.

You suck test to determine that the EGR is operational. Here's how, -

Withe the vehicle running at idle, disconnect the green vac line from top of the EGR valve, like you did before. Connect a scrap piece of hose to the EGR stem in place of the green line.

Suck on the hose like your drinking a milk shake. If the the idles way down, almost stalls then your EGR valve is operational.

SLAYER6708

OK thanks! I'll try that when I wake up later on today.

Jbrew

No problem.