2.9 losing power after 15 mins

[Johng2203]

Hey guys this is my first post! I have a 1990 Ranger 2wd 5 speed with the 2.9 and 143000 miles on it. I began driving it to work and back, which is about 20 mins, and have noticed a significant lose in power and a rough idle. It does very well for the first 10-15 mins but then it begins to become more gutless than it usually is. This especially happens when going up the slightest hills. I would have to down shift and end up going up the hill going 25 mph when the speed limit is 50 mph, still almost not making it up. And even when I downshift it still drops speed. Then when I stop it will get down to like 500 rpms and sometimes even stall on itself. It does not have clogged cats. I have replaced the coil, plugs, wires, dist cap, fuel filter, fuel pump, air filter, and o2 sensor. I have asked around and nobody has had an answer. Thanks in advance,
John

 

[Nez'sRanger]

Whole this won't fix your idle issues, I almost guarantee that your throttle cable is stretched and it's not allowing you to reach top speed.

Throttle Cable Mod - The Ranger Station

Submitted by ‘Destroy’ – Forum Member Over time, the throttle cable stretches and the housing seats more into its ferrules, thus, adding play to the gas pedal. You never feel this because: a) it happens so slowly and b) the … Continued

www.therangerstation.com

I would look into your fuel pressure regulator. It may very well be toast. The first thing to do is check for gas in the fpr's vacuum line (that indicates a bad unit), and then I'd hook up a fuel pressure gauge to the fuel rail and make sure it's getting the proper pressure.

Injectors may be clogged up a bit as well.
After you look at the regulator, I'd run some fuel system cleaner through it. I have some buddies that swear by the Chevron Techtron stuff. It definitely sounds like she's starving most the time. Mine was pretty bad when I first got it too! Nothing worse than crawling up a hill on a California freeway at 30, when everyone is flying by at 75+! Haha!
I've since changed every fuel system part besides the rail and lines (among others).

 

[Terry]

It sound like you have an issue after it is in "closed loop". This is when the engine is warmed up When it is cold it bypasses most of the sensors. When it warms up the oxygen sensor starts controlling the engine. It will run good until it gets warmed up. You need to check the trouble codes before you dump anymore money into it. Most autoparts stores will check code for free. You can buy a code reader for less than 50 dollars. Have you looked at the color of the spark plugs after it has been running crappy? They not be black and smell like gas. You could have an ignition control module going bad. When you climb a hill it need more advanced timming and fuel. If the timing won't advance it will fall on its face. Oxygen sensors need to be replaced over time. It is located on the lower passanger side if the exhaust. It is threaded into the pipe with a few wires on it.

 

[franklin2]

It sound like you have an issue after it is in "closed loop". This is when the engine is warmed up When it is cold it bypasses most of the sensors. When it warms up the oxygen sensor starts controlling the engine. It will run good until it gets warmed up. You need to check the trouble codes before you dump anymore money into it. Most autoparts stores will check code for free. You can buy a code reader for less than 50 dollars. Have you looked at the color of the spark plugs after it has been running crappy? They not be black and smell like gas. You could have an ignition control module going bad. When you climb a hill it need more advanced timming and fuel. If the timing won't advance it will fall on its face. Oxygen sensors need to be replaced over time. It is located on the lower passanger side if the exhaust. It is threaded into the pipe with a few wires on it.

I agree with the above. If you want to experiement and check this theory, go and unplug the oxygen sensor wire and drive it like that. When the computer goes and looks at the oxygen sensor to go into closed loop, it will see the oxygen sensor is not ready and it will stay in open loop. If the power doesn't drop off like it was doing, this would confirm what the previous poster was saying.

 

[Johng2203]

Ok thank you I will try these things tomorrow!

 

[Johng2203]

Sorry for getting back to you guys so late. I unplugged the o2 sensor and ran it and it was better but it was still acting up. And I checked the spark plugs and they still looked good. I also forgot to mention that I replace the ignition control module. I also put fuel additive and oil additive into it tonight just to try and clean the fuel and oil systems. So, are there anymore suggestions for my problem? Thanks

 

[rusty ol ranger]

Sorry for getting back to you guys so late. I unplugged the o2 sensor and ran it and it was better but it was still acting up. And I checked the spark plugs and they still looked good. I also forgot to mention that I replace the ignition control module. I also put fuel additive and oil additive into it tonight just to try and clean the fuel and oil systems. So, are there anymore suggestions for my problem? Thanks

Mine 87 did the same shit.

New injectors took care of it.

 

[Johng2203]

We ran the code and it is still saying o2 sensor so now we are thinking the ecm? Wouldn’t bad injectors cause power loss all the time? I put fuel and oil additive into it just to clean it out also

 

[rusty ol ranger]

We ran the code and it is still saying o2 sensor so now we are thinking the ecm? Wouldn’t bad injectors cause power loss all the time? I put fuel and oil additive into it just to clean it out also

Mine alwaya threw an O2 code to.

I as well changed the ECM.

What i had going on was the injectors wernt completly plugged, so when the engine was cold and calling for lots of fuel it was ok, but when it got warm and trimmed back it wasnt enough, and since i had 4 good injectors and 2 bad, it was enough to throw the O2 lean, which told the ECM to pour fuel to it. So then the 4 good injectors were flooding the motor making it nutless.

Trust me it was frusterating as hell and took me over a year to figure out.

 

[franklin2]

The EECIV system can be very frustrating. Nice running little engine being crippled by a bad connection or little electronic component somewhere.

 

[rusty ol ranger]

The EECIV system can be very frustrating. Nice running little engine being crippled by a bad connection or little electronic component somewhere.

I agree 100%.

 

[Johng2203]

Ok thank you I will look into this!

 

[Johng2203]

Hey guys I know this thread is old but I was just wondering where the fuseable link is for the o2 sensor. I’m wondering this because I found a video on this same issue and he replaced the fuseable link and it ran fine. He shows a grey connecter that a blue wire going into which then goes to a grey and yellow wire. But unfortunately I cannot find any of these things. Any knowledge of this will help! Thanks again!

 

[franklin2]

Hey guys I know this thread is old but I was just wondering where the fuseable link is for the o2 sensor. I’m wondering this because I found a video on this same issue and he replaced the fuseable link and it ran fine. He shows a grey connecter that a blue wire going into which then goes to a grey and yellow wire. But unfortunately I cannot find any of these things. Any knowledge of this will help! Thanks again!

What year and engine are you working on? They changed it as time went on.

 

[Johng2203]

What year and engine are you working on? They changed it as time went on.

It’s a 1990 and has the 2.9