1999 b2500 5 speed
since april I have had the following issues
cel= miss fire on #1+2 cylinder
in the morning when the engine is cold it idles rough, when I come to a stop the rpms will fluctuate between 500 to 1500 bouncing back and forth, or the engine will just die. It will start up again within a min. hesitating the whole time. By the time I get on the highway about 7 miles every thing seems to smooth out except for the hesitation. after 35 miles of highway when I exit it may or may not stall out. With everything repeating it self on the commute home.
To date I have done
timing belt
spark plugs all 8 and wires
both ignition coils
fuel injectors on #1+2
cleaned the maf,iac
looked for vacume leaks could not find any.
fuel press checked good 62psi
comp check cylinders all at 160+
as far as I remember that's everything.

any help guidance would be appreciated
thanks

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99 B 2500 200,000 plus miles

What plugs did you use? Rangers are legendary for only liking Motorcraft/Autolite double platinums. Anything else and problems happen. And what wires? Consensus here is again Motorcraft wires are necessary. What coil packs did you use?

Comp check good, fuel pressure looks fine, maf and iac should be good after a cleaning. Good checks performed there- first checks that would have come to mind if I had this issue.

Assuming you used the right plugs/wires/coils, im going to lean fuel related. Whens the last time the fuel filter has been replaced? Could be limiting flow. Hook up a scanner and tell us what the long term fuel trim is- high negative values indicate a sticking injector or bad fuel pressure regulator. High positive values indicate a clogged injector or vacuum leaks (in case you missed one- they can be tough to find).

Bad gas?? Over how many tanks have you had this issue? Might need to have the tank drained, some new good quality gas from a different station (like a shell instead of mom and pops gas), and maybe run a can of seafoam in 1/4 tank of gas to clean the fuel system a bit. You could also run some seafoam through the brake booster line (watch a video on this- you have to be careful!). Maybe some deposits are causing issues? I admit that this is a long shot, though it may very well help when added to the gas tank.

Finally, and this is a stretch.. EGR valve issue? Usually its going to throw a light, but stranger things have happened.

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2002 Ford Ranger XLT Supercab, 2.3L Duratec I4, 5-speed manual, 4.10 gears, ~100,000 miles
Power nothing with air conditioning; crank windows for life!
Throttle cable mod, retained accessory power mod, 2006 thermostat w/resistor mod
Headlight relay harness, Philips xtreme-vision bulbs
P235/75R15 Michelin LTX M/S2s

The plugs are nkg ,plug wires not sure but they are what autozone said rangers take I changed them back in april, the coilpacks are duralast. I put those in last week. I did try seafoam but just put it the gas tank. I do use a mom and pop store gas, but sign says citco. And ive had this issue since april. As far as the scanner I did buy one from harbor freight, but returned it the scanner would go blank after 1 min. After this tank of gas I will try some pure gas( non ethanol )and look again for a vacuume leak thanks

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99 B 2500 200,000 plus miles

Have you checked the temperature? Two things. The coolant temp will affect how the engine runs when cold or hot. The sensor that informs the computer will have effect on the fuel delivered. So it could be the thermostat or the sensor.
The upper radiator hose should get so hot you will NOT rest your hand on it for more than an instant. Ditto for the heater hoses, BOTH should be hot. If not, suspect the stat.
The sensor varies the ohms it reports to the computer based on temp. You can measure across the terminals cold, or terminal to ground, and compare to a hot reading.
I would also take a good close look at whatever is connected to the #1 & 2 intake runners, or the attachment of the manifold to the head. A bum gasket can ruin the mix and lead to misfire and stumble. It may be leaking underneath.
tom

GSF1200s thanks for the input. Just finished doing the seafoam and I will be revisiting vacume leaks later in the week.
tomw0 the temp seems to be ok you can see the temp. fluctuate on the temp gage, although the gage never goes higher then half way in the range. I have not looked at the sensor yet. Thanks again I will keep you posted.

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99 B 2500 200,000 plus miles

That is a different sensor, there are two sensors in the t-stat housing one is for the dash guage and one is for the ecu.

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2014 F150 xl 3.7 6 speed auto.

HI state ranger You are right, but I was referring to the radiator getting hot. that sensor is on my list of things to look at. It is starting to get frustrating! Reading through this web site it seems to be a lot of trucks with this problem to different degrees. any input would be appreciated .

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99 B 2500 200,000 plus miles

Fyi when you check the vacuum lines there is a short hose that connects the throttle body to the metal tube that runs between the 2 and 3 cylinders.

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2014 F150 xl 3.7 6 speed auto.

Any chance you have the 1+2 wires backwards/reversed?

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

hi modelageek no the wiring is good the coil packs are clearly marked.

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99 B 2500 200,000 plus miles

An interesting thing about the dual plugs is that you can have the 1 & 2 plug wires crossed on one coil pack and you will not really notice it.

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2014 F150 xl 3.7 6 speed auto.

Im sure that is the first thing I looked at after I did the timing belt and the problem was still there

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99 B 2500 200,000 plus miles

One thing a bad MAP sensor will do is cause an idle so shaky you can mix cake mix on the engine. If you have a swap available, it's worth a try. If you have a MAP. Later models of FoMoCo had both a MAF and a MAP.
When the engine is cold, it is running 'open loop', and injection and timing are 'fixed' more or less, but once warmed up, the O2 sensor comes into play and helps the computer fiddle with the mix. Seems it runs well in open loop, but not in closed, so that means it is not a mechanical problem, such as valves or rings, but an emissions component.
Does the engine smooth out just above idle speed?
tom

hi tomw0 the idle does smooth out between 1800-2200 rpm great at high way speeds

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99 B 2500 200,000 plus miles

Take it to a parts store and pull the codes, if any. Don't just buy parts based on the codes.
Does it hesitate when you accelerate? Is the miss at idle speed constant or intermittent?

Would you say, in short, the problem is that it runs poorly and stalls when cold, but finally runs well when warmed up?
tom