1998 Ford Ranger misfires

[rbilsland]

1998 Ford Ranger, 2.5L, 4 cyl, manual trans. Never have had any problems with starting or running. Now engine misfires intermittently at all speeds and temperature. Not running hot. Changed all plugs and wires. No improvement. Any suggestions for what to try next? Thanks in advance

[rdavid8221]

Originally Posted by rbilsland

1998 Ford Ranger, 2.5L, 4 cyl, manual trans. Never have had any problems with starting or running. Now engine misfires intermittently at all speeds and temperature. Not running hot. Changed all plugs and wires. No improvement. Any suggestions for what to try next? Thanks in advance

Define what you mean by misfireing. Does your truck make a popping noise? Or is it just sluggish and feel like it wants to stop when you step on the gas hard? If it is popping check your timing first. If you cannot seem to adjust your timing the problem could be the timing belt. If it feels sluggish or feels like it is hesitating when you step on the gas real hard then change the fuel filter. How does the truck idle?

[rbilsland]

Originally Posted by rdavid8221

Define what you mean by misfireing. Does your truck make a popping noise? Or is it just sluggish and feel like it wants to stop when you step on the gas hard? If it is popping check your timing first. If you cannot seem to adjust your timing the problem could be the timing belt. If it feels sluggish or feels like it is hesitating when you step on the gas real hard then change the fuel filter. How does the truck idle?

Misfireing: not all cylinders are fireing or sparking. Somethine when I push on the gas it accelerates just fine. Other times it accelerates, but you can feel like all 4 cylingers are not working. There is no popping sound or backfiring. This is definitely a mis-fire problem or some type of fuel injection(if this Ranger is fuel injected????) problem. When at a stop, it ofter(but not always) is idling very rough and shakes. This doesn't seem like a timing problem, but I'm open for suggestions. Thanks you for responding to my problem. Randy

[rum runner]

Yes, that Ranger is fuel injected.

Might be ignition coil pack?

Might be distributor?

Go by Auto Zone and they can do a diagnostic.

[Psychopete]

Originally Posted by rbilsland

Misfireing: not all cylinders are fireing or sparking. Somethine when I push on the gas it accelerates just fine. Other times it accelerates, but you can feel like all 4 cylingers are not working. There is no popping sound or backfiring. This is definitely a mis-fire problem or some type of fuel injection(if this Ranger is fuel injected????) problem. When at a stop, it ofter(but not always) is idling very rough and shakes. This doesn't seem like a timing problem, but I'm open for suggestions. Thanks you for responding to my problem. Randy

Sounds like the air fuel ratio is off. When I run my MAF on direct mode (IST air adjuster) it runs exactly llike that. The only thing you can really do is scan the codes. Have you looked at the plugs to see how well the truck is running?

Pete