95 ranger help

[bob long]

I have a 95 ranger with 25500 on it. I put a new head on it and it ran great for 3 months. Last week I get a misfire and lean code and my idle has turned to crap. Even with the bad idle it runs great, it doesn't feel like it is misfiring, and has good power. I have looked everywhere for a vaccum leak and i can't find anything. have checked fire, coils feul pressure, put noid lights on injectors they all check out fine. What can this be

 

[RangerX]

Welcome Bob! Which engine does it have?

 

[bob long]

bob long

2.3 I am stumped

 

[Tbars4]

I'm going to take a guess that you have 255, 000 miles on the vehicle.:scratch:

Have you scanned for stored codes, cleaned or replaced the MAF or the idle air control (IAC), checked the pcv, changed plugs wires or air filter recently?

 

[Runnin'OnEmpty]

Check for a vacuum leak at the brake booster or
the booster check valve. Press on the brake pedal
and listen for a hissing noise inside the cab.
Try pulling the booster hose off and plugging the
end; see if the idle improves.

The lean code and rough idle points to a vacuum
leak of some sort...

 

[bob long]

I have replaced all of these iac, pcv, cleaned the maf, replaced air filter, plugs and wires checked spark, did a noid light on injectors can't find any hissing with stet, what else is there that i'm not getting, thanks for the help

 

[Tbars4]

..Play with the brake booster grommet as mentioned above and also look for a broken small plastic vac line by the heater fan, and inspect the globe for the vac lines behind the pass headlight..

 

[bob long]

it seem that every day the idle changes now it is idling high went down the street and the idle spikes way up when changing from 1st to 2nd and also to third. Found the brake booster gromet a little loose but the ball behind headlight the lines are fine

 

[Tbars4]

..It sounds like you have an intermittent vacuum leak..:scratch:

..It's as hard to find as an electrical short..

..Usually, a shrunken grommet (such as the pcv and brake booster grommets) are the usual suspects as well as a crack in elbows (like the pcv) and cracked vac lines) as well as that ball and gaskets..

 

[bob long]

should i take it for a smoke test the problem i have is i don't have a shop that i trust

 

[Runnin'OnEmpty]

Those booster grommets and check valves can be
found at any parts store, and are inexpensive.
Since yours is loose, there's a good chance that's
the problem.

There's also a vapor line that comes from the
charcoal cannister and connects to the throttle
body (usually on the underside; hard to see).
These hoses are prone to falling off, cracking,
etc. and will cause a vacuum leak. It might take
a small mirror and droplight to examine it...

 

[bob long]

I have pressed on brake pedal and have hissing but i dont see a vac hose under there where do i look need help

 

[Runnin'OnEmpty]

Since yours is a 2.3L I'm not sure where the
vapor hose runs. You might have to find the
charcoal cannister and trace the hose coming
out of it.

Does the idle speed change when you press the
brake pedal? (Booster leaking)