Hey guys, new to forum and looking for some answers.

2003 Ranger 2WD 3.0L flex fuel.

Ive replaced: Coil Pack, Fuel Injectors, Wires, plugs, Cleaned Mass Air Sensor, Cleaned Throttle Body, and Fuel filter Replaced, Throttle Position sensor new. Still has no power when it is warmed up.

When the throttle is opened all the way it does not down shift and has no power with a bad mis-fire. Ive got 60 PSI fuel Pressure. new good injectors rated for the flex fuel 3.0l- and are Ford Brand. To me it seems the Timing is backing off, alot. Enough to cause such a power loss that it barely will go up hills, and I live on a steep one. Engine has never over heated. had 3K mile oil changes with full synthetic. Im a Mechanic, Specifically suspension and chassis. This has me boggled. Ive read Cam Shaft sensors and crankshaft sensor too, but I only got one code, a P0306- Cyl 6 Misfire Detected and that bank was running lean. So I had the injectors tested and that bank was bad, and I replaced them. Other side was great.

The PCM module on the Passenger Firewall does match for model year, and it says REMAN on it. My luck with anything REMAN has not been pleasant. But that is 500.00 for a new one last I checked. I did not install this. Im also not the original owner, but I know the guy I got it from very well and he is **** about matainance, He tried to get this bouncy Idle figured out since he bought it with 5 miles on it. I didnt worry about it. He didnt install this PCM either, so maybe when FORD had it they tried swapping stuff.

PCM
Cam Shaft Sensor
Crank Shaft Sensor.
If one or more of these isnt it Im going to have to Dive deeper.

Thanks guys.

 

Have you pulled codes or done a compression test?

 

Compression was good, but I am thinking I want to run it again.

Just one code- P0306. Thats it. Im not getting coolant into exhaust, I would have more than 1 Cylinder Misfire if the head gasket went between. I dont think it is a head issue.

 

Have you checked the ECT sensor?

 

Just replaced Slight Improvement. I am replacing parts one at time too.

 

throttle cable mod?

 

Throttle cable mod as in: Taking the slack out of it? Yes I have done that under the dash. Did that 4 years ago.


Intermittent Fuel pump pressure loss?? Under Load? Test PSI Key off- 60 PSI. Engine running 60 PSI. This is why Im lost. Ive got alldata and ford factory manual and a Haynes. Im soo lost.

 

that would have explained the lack of a downshift, but it's already been done, soo...

 

run the numbers on the PCM. If it is for a manual transmission truck, or diff auto trans it may still work but will get weird things to happen. That is assuming it never downshifted properly. Ebay PCM's could be found cheapppp.

Do a comp test again. If your #6 was running lean it could have burned the exhaust valve.

Could be a intake gasket leak on cyl # 6, causing to to go lean and missfire.

If you run out of things, pull the valve cover off and measure how much the rockers move the valves up and down for #6 compared to the other ones. Could be a worn out cam shaft lobe. Unlikey but if you run out of things, it's worth checking. I had an exhaust lobe wear out on me from an improperly installed cam(non-ranger), started with a miss, ended with backfiring hard thru the intake.

Something to note is that some of the vacuum sources are at the rear of the manifold, near the #6 cyl. So if you had a bad leak it could effect #6 the most.

I assume these don't have any vacuum lines running to the trans like older ones?

 

find someone with a solus pro and get it plugged in. watch every system while its running.

sounds almost like it jumped a tooth in the timing.

 

Does the truck run the same way, cold or hot?

 

do a compression test, and check for a plugged cat. both will cause huge loss in power.

 

Since last night when I unplugged the neg battery cable and left it off till I got off work here is what I have found:

2 Min into start of engine it runs ok, 10 min into drive cycle still ok, way better than before I starting swapping parts one by one and driving each and every time. but when the throttle is opened at the half point with a slight grade it starts to struggle at the 12 min mark. This is after I have given time for the Computers to relearn and the temp gauge is starting to climb to half way mark, it does not over heat. warmed up at the 15- 18 mark with some traffic, I rolled into the gas while moving and she started lacking power.

I have no way to test fuel pressure in a driving condition unless I get fancy and set up some gauge pods or something similar. Which, to me feels like the fuel pump is lacking pressure when the demand for more increases. I tried little throttle as possible and eased into ,it and it runs great when the demand for fuel isnt that great. As in the throttle isnt opened as far as half. The more level the road the better she ran, hills which I live on a pretty steep one to get home, was first gear and as little throttle as possible to avoid over doing anything on the 23 min mark. Im leaning to a fuel pump taking a dump.

I have heard of fuel pumps doing this, Only heard of it. But I have changed a fuel pump on a 2004 F150 new body style that this was the start of a faulty pump. The guy who sold me this truck Used the money to buy his F150. His pump started doing something similar but was intermittent. Would run good one min and crappy the next, turn the key off and let it sit would run fine, give it 20 min and would do it again, run crappy.

She shifted fine before this issue and ran fine, but seems to be that everything slowly degraded and pooped all at once, I chasing this last gremlin.

Thanks for the Replys guys, sorry for so much info! Lots of stuff to read.

 

Dont think so on jumping a tooth, Ive changed all that when I got the truck. With Ford brand from Ford. That was 30K miles ago. Valve Train is also pretty quiet, Motor is quiet. Exhaust note is great, well was till this issue.

On the Solus from Snaps, I do know people with them but they want about 120.00 an hour, or they cant get me in till next week or the next week. I want My baby back.!@@!!

 

How many miles on the engine? Have you done a compression test with the engine warmed up?

 

just rolled 141K and that is right when it started acting up. and no I havent tried that, didnt think to. But then I also thought that maybe that would be bad for me and maybe that head when the plugs go into. I could try it I suppose.

 

i heat related problem that causes a lack of power. with all sensors covered, sound to me sir like you've got a plugged CAT.

i hear ya with the scanner. thankfully im friends with my shop foreman, (i work sales) and gladly get to use it any time i like. lol

 

I don't see anything about replacing the Engine Coolant Temperature Sensor?? Remember there is a separate sensor for the gauge and the engine, so if your gauge is working that doesn't mean the engine sensor is working. If it doesn't realize that the engine has warmed up it could do funny stuff. The sensor is about $20 and takes about 5 minutes to swap.

I don't know about this specific computer but some run in a dumb mode until the engine warms up. That is, it ignores certain sensors until the engine has come up to operating temps. So it could be ignoring the O2 sensors for example, and once it hits operating temp it starts reading it, and gets a bad reading and takes a dump. Try unplugging sensors to see what happens. Typically if a sensor is unplugged it will just take it out of the computers calculations.

 

I suggested the ECT earlier, the OP stated he had replaced it recently.

 

The cats are fine, Ive eliminated everything and keep coming to a Intermittent Fuel pump issue. Pump is fine while cold, after it starts to heat up from working is when it actually loses pressure at the rail. Got a realllly long fuel PSI tester and took her for a 20 min drive and BOOM, fuel pressure degrades so fast we are surprised she runs at all. The more the pump has to push fuel the hotter she gets and wants to shut down. and If it were the cats with my experiance, It would not want to start and would be this misfire all the time and kill the motor due to really excessive back-pressure. I doubt it is them. Ive owned GM's and all 3 of those burned down causing so much failure so quick we thought we blew a head gaskets. My Cavalier burned it down 2 weeks after I got the CAI kit on. IT was that fast about it. was not gradual, just melted down to the point that it would not run.

I also got to looking at my fuel log book: For the last 7 months, there had been times where the fuel gauge would be at half tank or at the 1/4 mark and Id go fill it up and she would take 15 gallons. I have a 15 gal tank..... I do believe I killed my Fuel pump not paying enough attention. But the fuel gauge was a liar all along.....

 

This happened to my ranger and it ended being one of the cats since the cat was partially blocked the O2 sensors were trying to cut fuel because they were reading super rich .This issue happen right after it warmed up when it was cold it had power.This is how I figured it out
I unbolted the big catalytic converter where the Y pipe meets it and turned on the truck and I put my hand on the two holes and right off the bat I could tell which side was clogged since hardly any air was coming out of it.Be careful when doing this try it when the truck is cold.

 

Im knocking the 2 upper cats out and welding in pipe anyways, those 2 upper cats are not needed for any reason other than Cali Emissions.. leaving the lower 2 cats in place as long as they are still good, they will get replaced with high flow if they do turn up bad. Ive been staring at the under hood of the truck for a long while and It dawned on me that those are not needed.

I planned on pulling the cat's saturday weather pending. Soaking in PB.

 

Did you change out that bad fuel pump yet??

 

After reading all this I personally would lean towards a fuel pump going out. You stated that sometimes it runs lean and that the pressure drops at speed or load. The good thing is is that it is easy to replace! I did mine about 6 months ago (thanks to everyone here on the site for all the help and hints!) I have an '02 with the 4.0 and my pump came out to $202 or so and it was an Airtex brand which I picked up at O'Reillys.

I hope you get it running soon because I know it sucks when you are without your vehicle or it is not running right!

 

Got the Pump and Scanner today, weather still too cold for my butt to put up with in a good mood and get this done. We are pulling the motor out of a 87 Isuzu Impulse RS Turbo, But we can push it outside.

Yeah, Im driving a 93 Park Ave......Not my truck by any means at all. Total for everything hit the 1100.00 mark as of today. I CAN keep throwing money at it but only going to be able to go so far with it before I call it quits and buy another 3.0L ranger 2wd and do the exact same to it. BUT I WILL get this figured out. 2 day weekend so She will run by Sunday, Otherwise Im still driving that friggin buick........