any advice for a 1999 ford ranger stalling problem would be appreciated. 1999 ford ranger with manual 5spd, 2wd, 4 cylinder, originally had a P0401 egr type code, cleaned the throttle body, and MAF sensor, replaced the DPFE sensor, O2 sensors, IAC valve replaced, and the vaccuum control for the DPFE sensor, checked all the vacuum lines, ranger check engine light went away, then began stalling on gear shift, idles fine, but will sometimes stall when shifting gears at lower speeds or from a start, otherwise runs like a top. thought i was onto something with the dpfe/iac/vacuum control change and the throttle body clean and it does run better (at idle) since the change but the stalling remains, kinda stumped, any help would be appreciated....

 

I have same problem. Dealer has replaced the coils (no help) switched the injectors around (no help) replaced IAC sol. replaced MAF, dpfe. I have 65 psi fuel psi. My problem is worse when cold when shifting. I have same truck as you do. My only codes are 1451 evap and #2 & #4 cyl misfire. I have 20 " vac and steady no intake leaks. Last night I took my timing light and hooked it up to the different plug wires and drove it to see what the plugs are doing while driving (i know sound crude but I wanted to know if it is fuel or spark) and the spark is erratic at best from all cyclinders but not sparking at all on the decell for #1, #2 on the exhaust side, the #3 on the exhaust side is a little better maybe 50% of the time it sparks on the decell and the rest are are just erratic.

I have been doing research on this for about 2 months. I have come across alot of posts and they all either have no replys or they say it is the IAC sol.

The dealer has given up........ they told me the lifters are sticking and want to replace them for about $375 and "that might not fix it" I bought this truck about two years ago it had about 130k on it and the problem was just slight but it is at 167k and is to the point that it is stalling to often when decelerating and sometimes when it stalls it is missing so bad it will hardly start mostly when in open loop.

This truck runs good at cruise but with the timing light on it i see it is missing so at cruise also.

Oh yeah new plugs and wires also.

I know this doesnt help you but venting is helping me.

Thanks................still looking for the problem.

John

 

One thing not mentioned in either of the above posts was the Throttle Position Sensor.
It may have a dead spot (or 2) or needs to be adjusted.

 

Sweep test is good.

 

I just cleaned all the grounding straps looking for a bad ground.

 

I'm not sure if this has anything to do with your problem, but I just found something written about the TPS. It says if you adjusted your idle screw at all you may have to adjust the throttle position sensor also. Apparently if both are not set right it will cause all sorts of problems.
The Ford Ranger Throttle Position Sensor

 

I have not been messing with the idle stop screw.

John

 

doesnt mean it didnt get moved but check it any ways

 

I'm not sure if you can actually adjust the TPS. My Hane's manual says it's not adjustable.

 

my truck was stalling also (99 four cylinder five speed) and the speedometer wasn't working properly. replaced the speed pickup on the rear axle and cured both problems

 

Ok an update on the mystery misfire. I have been chasing this one for a long time as you can see from the posts. My condition came to halt about a month ago when the engine quit on my drive home. Timing belt snaped while at cruse. Installed new belt, idler, water pump. Thought I would dive into this misfire again as my milage dropped to 18 mpg from 28 and the power has also droped. I have read many other posts in a few forums with the same problem and no real answer, I dont know if they gave up or what. Other post have suggested a bad computer because the coil driver is in the computer. Others say crank position sensor. Well ad those to the list of new parts (except the computer, I found a used one for $75). Plugged exhaust was also mentioned. I unbolted that and the same problem. I did a compression test and 185-180 on all 4 cyclinders. I keep thowing missfire cyl #4 and some times #2. I kept driving untill it was hard for anyone to drive it as it stalled every time the throttle was snapped closed like when you push in the clutch to come to a stop.

I pulled the head off to take a look and did not see anything obvious like blown gasket or crack between valves. I took it to the machine shop and he said I can see your problem right here. Your exhaust valve seats have recessed.

Read this article: The Misfiring Ranger Mystery

http://www.atsnm.com/pressuretransdu...gRangerMystery

My guy at the machine shop explained it to me and it makes sense. The 2.5 has a lifter to take the slack out of the valve train and as the valve seats wear and recess the valve lash that the lifter takes up is now gone and the lifter bottoms out. Eventually the valve hangs open this happen only when running as the oil pressure pumps the lifter up and opens it even farther but only when running. When the engine is off to do a compression test the oil pressure is zero and not pumping the lifter up. When I looked at the valve and compared it to the other valves it looks like the exhaust valve in the #4 cylinder sits 1/8 inch deeper in the seat than all the others.

After reading the article I wonder why my ford dealer did not check for TSB's

I will post after I get it back together. The shop will not have the head ready until Friday or Monday.

 

Well my cylinder head turned out to be cracked also between the intake and exhaust valves on the #1 cylinder. The valve seat recession was really bad on cylinder #4 exhaust valve, intake was ok. Also slightly recessed on the exhaust valve on the #1 cylinder, intake ok. My machine shop could not find a cylinder head through his supplier. I found a used engine on craigs list for $350 with 67k on it and swung that in about a week and a half ago. Purrs like a kitten. Hope this helps others out.