2.9 losing power after 15 mins

[franklin2]

Below is a diagram from this site's tech files. I don't know what exact year the diagram is for, but I can tell that is later than my 1986. You can see in the diagram below, there is no fusible link for the oxygen sensor heater, there is a fuse instead in the fuse box. Fuse #18, 10 amp.

 

[PetroleumJunkie412]

Any updates??

 

[Johng2203]

Below is a diagram from this site's tech files. I don't know what exact year the diagram is for, but I can tell that is later than my 1986. You can see in the diagram below, there is no fusible link for the oxygen sensor heater, there is a fuse instead in the fuse box. Fuse #18, 10 amp.

Ok thank you I will check that fuse!

 

[Johng2203]

Ok thank you I will check that fuse!

I checked the fuse and it still looks fine (the band is not broken in between).

 

[Cees Klumper]

My '90 also suffered from poor accelleration once warmed up. I had replaced the O2 sensor as it had given me that code, but what ended up clearing it all up (last Sunday!), was putting in rebuilt injectors. I got mine just two weeks ago, from CS Performance Fuel Injectors (https://www.cspinjectors.com/).
It cost just under $60 delivered, for 6 rebuilt and flow-matched Bosch units, and they made a world of difference. Before, if I would push beyond say 2/3 throttle on a warm engine, it would just not respond but would actually sort of 'sink', and you could feel the ECM adjusting the settings 'back' as it was apparently being starved for fuel. Only if I floored it would it sort of pick up again. Now, it pulls strong all throughout the rev range and has become positively quick. If you don't know the state of your injectors, I would definitely recommend putting in a fresh set like I did. It may not be your issue, but it's an inexpensive measure that will probably help your engine in general anyway.
P.s. I also looked for a fusible link on mine and could not find it. I did replace the fuel pump relay and the ECU relay, underneath the fuses box, as these can also cause issues. Another relatively inexpensive and worthwhile measure. Good luck with the fix.

 

[bobbywalter]

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.

No. You listen like old people copulate.

 

[Johng2203]

So I finally got my injectors in after waiting for them to come in for just about 2 months and when I put them in and started running it, it runs worse. It now doesn’t have power at all and is totally gutless all of the time.

 

[rusty ol ranger]

So I finally got my injectors in after waiting for them to come in for just about 2 months and when I put them in and started running it, it runs worse. It now doesn’t have power at all and is totally gutless all of the time.

Pull the plugs. See what they look like.

 

[Johng2203]

Ok I will

 

[Johng2203]

Pull the plugs. See what they look like.

I finally got time to pull the plugs and they look fine. So I’m not sure where to go next.

 

[rusty ol ranger]

I finally got time to pull the plugs and they look fine. So I’m not sure where to go next.

Check fuel pressure at the rail.

If that checks out (40psi) then crawl underneath and remove the fuel line from the little black can on the inner drivers frame rail, turn the key on, you should get a steady flow of low pressure fuel.

Your intank pump may of failed.

 

[wildbill23c]

Check fuel pressure at the rail.

If that checks out (40psi) then crawl underneath and remove the fuel line from the little black can on the inner drivers frame rail, turn the key on, you should get a steady flow of low pressure fuel.

Your intank pump may of failed.

This is what I'm wondering on my 87 2.9L Ranger too. I'm having the same issue as Cees Klumper describes....I thought fuel injectors, but if that were the case I'd think the power loss would be all the time, not just certain times, and random conditions. Just hate thinking about the mess to get to that fuel pump in the tank as I'm leaning towards that as being the problem as well, maybe not failed completely but intermittent. Going up the hill out of town I have the trouble, possibly caused from that reservoir running out of fuel, and the in-tank pump not having enough pressure to keep that reservoir full so just about at the top of the hill it'll lose power and start bucking, and starving for fuel, then if you floorboard the accelerator it'll pickup and and be fine....maybe a combination of both injectors and that in-tank fuel pump being weak.

 

[rusty ol ranger]

This is what I'm wondering on my 87 2.9L Ranger too. I'm having the same issue as Cees Klumper describes....I thought fuel injectors, but if that were the case I'd think the power loss would be all the time, not just certain times, and random conditions. Just hate thinking about the mess to get to that fuel pump in the tank as I'm leaning towards that as being the problem as well, maybe not failed completely but intermittent. Going up the hill out of town I have the trouble, possibly caused from that reservoir running out of fuel, and the in-tank pump not having enough pressure to keep that reservoir full so just about at the top of the hill it'll lose power and start bucking, and starving for fuel, then if you floorboard the accelerator it'll pickup and and be fine....maybe a combination of both injectors and that in-tank fuel pump being weak.

All i know is i was having more less the same symptoms as yall, 2 new pumps, new FPR, and 6 new injectors fixed it,

 

[wildbill23c]

All i know is i was having more less the same symptoms as yall, 2 new pumps, new FPR, and 6 new injectors fixed it,

So a new fuel system fixed it LOL. I was going to start with injectors and go from there but they're a bit expensive to have to buy all 6 at a time. About $30-80 a piece.

 

[rusty ol ranger]

So a new fuel system fixed it LOL. I was going to start with injectors and go from there but they're a bit expensive to have to buy all 6 at a time. About $30-80 a piece.

I shouldnt have but i bought a set of chinese cheapos of ebay. 60 bucks for 6 and theyve worked great. I bought the cheapos cause i didnt know if it was gonna fix it or not.