I'm at my whits end, maybe someone has some advise....
I have a 99'(2.5l, auto) ranger that when get hot(60-80 miles/hot day),begins to lose power; starts chugging. It get so bad, that it dies at the intersection!
Putting the pedal down only increases the problem, it's like it isn't firing on all cyclrs.
I have ruled out the common problems-all new: plugs/wires/fuel filter/cat convrt- even put in new fuel pump. Used carb cleaner, and add to gas. Ford says the problem is because of the autozone fuel pump, but it was doing this before I put the fuel pump in.
Runs like a dream when cold, just screws up when hot/warmed up. Sometimes the motor shakes so bad, I think its going to explode. This can't be good f/ it!
I was thinking coils, something elect; but, if it was elect. wouldn't it happen all the time?
Any advise w/ be appericated............
capkid

 

How is the cooling system. Radiator and water pump?

 

Don't know cooling system shape, but new rad. cap.
Gages don't show a overheat condition; motor not overly hot.
On a hot day is happens sooner, but nothing different.
Could it be the coils?

capkid

 

how many miles are on it?
does it burn any oil?
you say when it gets hot, is it still in the recommended temperature range?

 

My '88 2.9l did exactly the same thing, no codes would scan KOEO and when cold it was fine. I finally did a KOER test and pulled an "always lean" O2 sensor code, replaced the O2 sensor and cured the problem. I even took it to Ford and let them charge me $32 to check all the things I had already checked, before I tried the KOER test. It sounds suspicious, mine acted exactly the same as your description. Just my experience.

 

Thanks f/ all your replys.........
It's got 106,000. No oil burning that I can see. Runs about med. temp on gage-feel motor, not overly hot.
I stalled again at the intersection;restarted (almost didn't) and went to the side. Waited a min., restarted- ran like a champ. I quess (?) I can rule out a mech. problem. What I did w/ a reset(?), so it must be elect. Others have quessed coils; I bought two. I w/ wait to put them on until I hear f/ u'all.
The sensor idea sounds right on. O2 sensors or coils? What do you think is my best bet?
I really appericate all of your help.........

Capkid

 

It depends. Has your mileage been affected notably? If it's running rich you'll loose mileage, if it's running lean you may not notice any difference but you should smell an odor similar to burning plastic from the exhaust. Coil is a good guess as well, they are notorious for failing when hot. Easiest way to check that is to check the distance your spark will jump when it's running poorly, a weak coil gets weaker as it gets hotter. No definites, but I'd say we're on the right track anyway. Keep us posted.

 

Woe is me.............
After $100 of coils; I still have the same problem. After a short downtime, runs good(not dying). "Shotgun" repair f/ me
Ok, time f/ O2 sensors.
Where: on pipe?
Many: 2?
Both or one?
I"ll fix it if I have to replace everything!
It's making me mad!!!!!!!!!
Thanks f/ your help
Capkid

 

I highly recommend that you don't continue to throw parts at this. It may be O2 sensors, but guessing at it may well cost you a chunk of change to go nowhere. At this point you may want to take it somewhere to have the codes scanned. I know I know, DIY self help forum member suggesting that you take it somewhere, but if you don't have the means to at least do some diagnostics you are just guessing, and generally guessing is more expensive than paying someone to fix it the first time, as you've already found out with the coil pack. IMO, take it to Autozone or the like and have the codes scanned, go from there. Just my thoughts.

 

As the title says , this might be it . Common problem to many makes . I had a chevrolet ( long story ) did the same thing ; so did my brothers s-10 . If it runs ok for 30 mins or more and out of the blue, crap , this could very well be it . Rebuilt units cost about $100 . Hope you fix it . Good luck !

 

Ok, tried the reader method.....
No codes; no nothing. Used both autozone(running) and OBC ll(off). Haven't taken it to the ford shop; but they say it has to be screwing up to see. The problem is that it screws up after 60-80m. One w/ almost have to have reader in car to see w/ going on(turn off-no problems).
Am I missing something simple here(k.i.s.s.)?
Tranny,inject,intake???
I'm sorry to beat a dead horse here; but I have never seen anything like this before. Run so poorly, reset, ok.
Most people wouldn't see this problem; but I put +100m per day. Runs so bad, there's got to be something wrong!
Maybe my truck doesn't like me............
Please keep quessing..
capkid

 

BTT.
Anyone have a new idea, before I give ford my $$$$?
capkid

 

I don't think it is the coil packs....
I had both coil packs go out at one time one me and just the same cylinders on both coil packs went out on each side.. It just ran very poorly even from the start. Try the 02 sensor..