low power under 3000rpm

[killj0y]

Yea I feel you it felt like several little. Things added up in mine too. I've seen that site but some of the stuff seemed abit extreme or useless for that little engine, plus with no real. Instructions its kinda pointless. If you have a limited slip rear new oil and friction modifier might fix that. Also I need to check out my cat too. I feel my engine is running too cold gauge never moves past a centimeter above C lol how's yours act? This I think is lowering my mileage...but I still get 20 plus I think.

 

[fivestring]

No limited slip. Already took the diff cover off and cleaned it all thoroughly with brake cleaner. I could tell the shafts holding spider gears were sloppy and the gears themselves were worn.
Temp is on the cold end of the gauge. I still have some flushing to do as I just discovered I have no cab heat. I guess it didnt get turned on very often in Orlando...

 

[killj0y]

same here in south texas, but when i did use it last it blows HOT! so that is what seems strange...maybe it is just the gauge or something. damn...

 

[fivestring]

The story continues and still no resolution. This truck cannot continue to give 17MPG!!

I tested vacuum today. At idle it is steady at 22", which shows in the normal range on the gauge.

Also tested throttle pos sensor: 1.25v at idle, smooth climb to 7.0v at wide open.

Coil packs: primary ohms .9 (under 5 is ok). Secondary:all tested at 10.47-10.58K, lower than the 13-15k suggested by Haynes. Enough of a difference to warrant replacement?

Only codes showing are Evap emissions system and EGR due to blocking off the valve at the intake to try improving acceleration and fuel mileage. It did help acceleration a little. Not sure yet on the mpg, still around 17 or so.

Streaming data from an OBDII scanner shows #1 O2 sensor fluctuating from .1 to .8volts, #2 O2 sensor mimics the #1 sensor most of the time. Occasionally they both go rich (.8) and system goes into open loop for no apparent reason. A quick tap of the gas pedal will get them fluctuating again.

Coolant temp is 185-186°
Timing advance reported by OBD is around 10° at idle
Engine load at idle is about 30%
MAF shows around 30g/s on highway speeds.
Fuel pressure is 30psi at idle. I disconnected regulator vacuum and it went to 40. No gas in vac line there.

I'm wondering if anyone else has monitored their o2 sensors while driving. I would like to know if the readings I am getting are normal.

Computer was reset by disconnecting battery for 20 minutes.

Any ideas what to check next?

 

[rrbrian222]

What kind of driving are you doing that results in 17mph, highway, city, or some percentage of each?

My truck is the same as yours other than 15x7 wheels and 26" tall tires (extended cab as well). In the warm summer weather, I can regularly snag 21-22mph in mostly city driving, 25-26mph all highway. 17mph would be closer to my winter city mileage.

After I get my truck back on the road (doing the master/slave cylinders for the clutch) and some other basic maintenance over the next few weeks, I'd be happy to compare OBD-II values with you since I'll be ordering one of those laptop data cables and software.

But hopefully by then you'll have this resolved and you can post the fix for the rest of us that may encounter this issue at some point.

 

[fivestring]

My driving is a mix of country roads and highway. I take it pretty easy but being in S Georgia this time of year the A/C is on all the time.

I tried turning it off and, according to the Bluetooth OBD scanner and the Torque program on my droid phone, it calculates about 1-2 mpg improvement.

Just filled up the tank again last night, 18.22mpg.

 

[fivestring]

I tried today to disconnect the exhaust pipe from the header pipe. Cant get the bolts broken loose. I will have to take it to a shop that has a torch to heat the flange and break the bolts loose. I want to run the truck without exhaust to check restriction.

I discovered today my v8 Dodge idles at 10% or less of load according to the OBD. The Ranger is idling at 30% load. What the heck?

I really need to find someone with an identical setup so I can compare apples to apples.

 

[press 1 for english]

My best guess is the timing is a tooth or two off.
Easy enough to do when replacing the belt.

Are you kidding.......if the timing jumped a tooth or 2, the engine would idle but wouldn't have enough power to move.

 

[press 1 for english]

Would a tooth or two off allow for such a smooth running engine?

The idle and cruising performance never has even a hiccup. Starts in the first 1-2 seconds of being turned over. Aside from the low acceleration, the motor is velvet smooth.

The engine can idle but it would be undriveable with the valve timing belt off by 1-2 teeth. No way you could drive it.

 

[gjm4l]

ehhh my 92' was off by 1 tooth when I bought it and it was exactly like the op's issue seemed a little sluggish up to speed but did just fine once there. No other issues at all just sluggish. I did the timing belt a couple months after I got it and discovered it had jumped a tooth and afterwards it was noticibly peppier at least as much as a 160k 2.3l can be. Also improved my mileage from what it was.

OP if you can get above 25mpg in mixed driving let me know! I get 26 only on long, flat roads doin about 65 w/no AC (a problem I intend to fix) but otherwise 22ish in mixed driving.

 

[fivestring]

Finally had an opportunity to check compression: 145 across all cylinders.

Pulled the intake and fuel rail and cleaned injectors with carb cleaner. Also pulled fuel regulator and cleaned it. After reassembly I checked fuel pressure. 25 lbs with regulator connected. 35 lbs with it disconnected. I blew into the vacuum line and pressure went up to 38 lbs. I left the vac line off and plugged the port on the intake. I will be replacing the reg soon.

I have two new coils coming today.

 

[rangerbum]

The engine can idle but it would be undriveable with the valve timing belt off by 1-2 teeth. No way you could drive it.

I dont mean to instigate, but my 97 ran when it was off. I re-timed my truck, then drove it across the country(Montana to oregon, then california, then to Ohio, total of 5000 miles) with a 2000 pound trailer, only to get annoyed with the performance and find my timing belt at least 4 teeth off.

It will drive with poor power and rough running, but it will definitely get the job done. Even managed an average of 18 mpg the whole way.

 

[fivestring]

I put 2 new coil packs on, changed IAT sensor, eliminated cat and raised fuel pressure to 42lbs KOEO.

It is running better and better with each step but fuel economy hasn't jumped significantly yet.

I am considering taking the timing belt cover off again to look at the marks again.

 

[killj0y]

yea take a peek at the belt see if its way off or spot on. I've been meaning to get a bluetooth adapter to use with my phone and the torque app, but low on funds boo otherwise i might be able to help you out more.

 

[rrbrian222]

It is running better and better with each step but fuel economy hasn't jumped significantly yet.

I'm sure you've done this in the past but have you physically calculated your fuel economy or do you just rely on the telemetry that your software computes from the PCM? If you haven't, try filling up your tank totally full, reset the trip odometer, drive a hundred+ miles, fill up your tank full again and divide miles driven by gallons of fuel added to tank. See how that compares to your droid app. Just trying to think outside the box a little bit.....