'92 2.3L Ranger lacks power and runs lean

[pad2383]

Hi,

I've got a '92 ranger going on 210,000 miles. For the most part it runs great, but it lacks power on accelaration and at high speeds. I also think it could be getting better fuel efficiency (I average around 21mpg). I change the oil regularly, and I recently replaced the air filter, fuel filter, spark plugs, and spark plug wires. Pulling the old plugs revealed the engine was running lean. At high speeds on long trips the check engine light will come on. The code reader gave me the codes 334 (EGR closed-valve voltage higher than expected) and 172 ( Lack of Oxygen Sensor [Hego][HO2S-10] Switches, indicates lean). Anyone know what condition might prompt these two codes? I'd love some tips to get my truck running optimally. How can I get more power back, increase my fuel efficiency and correct the lean combustion. All information is welcome and appreciated. Thanks.

 

[steve63]

i'd check youre cat,o2 sensor,clean out youre EGR valve

 

[pad2383]

What's the best way to clean out the egr valve?

 

[steve63]

you have to take it off the intake manifold and clean it out along with the mounting serface,and the egr ports,but first see if it is working by hooking a vacum hose to it and suck on it,if its working the engine will stumble noticably.

 

[scotts90ranger]

I'd take the MAF off and clean it with some MAF cleaner, that can do some wierd things

 

[pad2383]

Thanks for all the advice so far. I took the MAF sensor off and cleaned it. From the look of it, it was pretty gunked up but I didn't notice any dramatic improvement after reinstalling it. I'm thinking the 02 sensor is good since the engine is running lean and that's exactly what the code from the 02 sensor indicated. I'm trying simple cheap fixes before I jump to anything expensive or complicated. I'd like to replace the PCV valve but I can't find where it is located. Anymore help on how to correct a lean running engine or where to find the PCV valve would be welcome.

 

[97ranger xlt]

suggest you reset the computer after cleaning the MAF, let it learn new fuel air trims

 

[pad2383]

Update: So I finally got my hands on a fuel pressure gauge and hooked it up. The manual said the fuel line should be pressurized to 40 PSI with ignition on, engine off, then with the engine turned on the line should drop in pressure by 3-10 PSI. Well, my fuel line pressure reading with ignition on, engine off was only 20 PSI, and then with the engine turned on it jumped to 30 PSI. So, I'm now pretty sure my lean combustion problem is related to low fuel pressure. With these readings anyone know what the problem could be? I checked the fuel pump fuse and it is clean and fine. Advice at this point is definitely appreciated. Thanks.

 

[Bryan22]

try changing the fuel filter and test again.

 

[modelageek]

Update: So I finally got my hands on a fuel pressure gauge and hooked it up. The manual said the fuel line should be pressurized to 40 PSI with ignition on, engine off, then with the engine turned on the line should drop in pressure by 3-10 PSI. Well, my fuel line pressure reading with ignition on, engine off was only 20 PSI, and then with the engine turned on it jumped to 30 PSI. So, I'm now pretty sure my lean combustion problem is related to low fuel pressure. With these readings anyone know what the problem could be? I checked the fuel pump fuse and it is clean and fine. Advice at this point is definitely appreciated. Thanks.

I agree with changing the fuel filter. another thing to check is to pull the vacuum line of the fp,itison the fuel rail. there should not ge any gas in the vacuum line. you proably have a bad fuel filter a bad fpr or a bad fuel pump.

 

[pad2383]

Changing the fuel filter was the first thing I did, so I know my fuel filter is good. I ran some more pressure tests today and as it turns out, everything is up to manufacturers specs. I don't have any gas coming out of my fuel pressure regulator, pressure increases when I remove the vacuum line to it, like it should, and I was able to get the 40 PSI by keying the ignition on/off a couple times to give the fuel pump a chance to build pressure without the engine on. Fuel pressure raises just like it should when the accelerator is pushed. Everything fuel pressure wise checks out so my initial reading on having low fuel pressure was wrong. My Pump, regulator, and fuel filter all check out. So I'm back to square one. What is causing the lean condition? I think my next move may be to replace the 02 sensor. Thanks for all the tips so far and keep them coming.

 

[pad2383]

Update: I've now replaced my 02 sensor but I'm still only getting 22 mpg. No improvements in fuel economy or power. I know this thing should be able to get 26mpg but how do I get it there?

 

[cmikee]

My 93 2.3 get's 21 if I drive it hard and 23 if I am easy with it. It always has.