1996 Ford Ranger - 2.3L Misfire #1 - Rough Idle

[steven kiser]

a couple of questions here. any codes? compression? you mentioned a knock, will it lessen or intensify by shorting cylinders. what i mean is if you can slightly move throttle up and down and while the noise is happening if you remove a plug wire it makes a difference, you'll need to do it to all cylinders. the noise is what's got me concerned. identify this first. if you're looking for the skip first you may be throwing good money into an engine that needs major work. we'll help talk you through it so please don't leave us hanging. this is much more friendly than most on line help services.

[steven kiser]

when you disconnect the injector you're in effect shutting the cylinder down. with the reduction in noise i'd lean towards mechanical damage in the engine.............................

[ricmorin]

Can you run an injector balance test?(ford factory scan tool) Or swap #1 injector and see if the problem moves? If you're scope savy you could do a waveform analysis on the injectors?

[ricmorin]

Oh. And this just dawned on me......

How about possible carbon buildup on backside of valve? Would explain why it's worse cold. Also, these have been known to have valve seat issues. The early stages only exhibit cold symptoms.

I'd borescope the engine to see more.

[ricmorin]

Right. Upper plenum comes off....about 1.5.

These are also known for skewed MAF sensors. There's a TSB on it although I've never seen one act the way you describe because of it. Worth a look. You can tell by looking at the BARO PID.

[steven kiser]

without the noise i'd say vac leak or bad intake. i've worked on plenty of fords and haven't seen this in this engine but on earlier ones i remember bad cams.

[steven kiser]

speaking for myself, i'd be more concerned with the noise.