New to the Ranger Forum since son bought 1996 Ranger with 2.3L Manual. (Another thing to keep me busy on the weekends!!). Has run decent but something ain't right! When he bought it had to change out fuel pump to get it running. Now I'm battling some performance problems. Idled funny (fast and then would die) along with some other transient issues so changed out Idle Air Control Valve. Also after having battery disconnected could barley get it started then it ran like complete trash until driving around for awhile to get things re-calibrated I guess. Now when I stop driving it will idle fast for a bit drop down run a bit longer then dies with a rattle! Does this consistently! So once I changed out the IACV, drove it around for a long time and main issue was lack of power/bogged down under stress (level ground ran through acceleration Ok but going up hills will bog down and lose power particularly at higher RPM). I can ease off the peddle a bit and get it to stop bogging down a bit but overall its pretty bad. Sooooo.. main symptoms I'm having:
1) Disconnect battery runs like garbage, barley runs no power wants to stall. Have to drive it around a lot and it seems to re-calibrate so will run and start not too bad.
2) Even when running Ok will bog down / lose power going up hills and have to ease off pedal to keep it going or I think it will die. Level ground runs pretty good.
3) Leave it idling and it starts off idling high for a 1/2 minute or so then drops down, then begins to sputter a bit then dies hard.
4) Took it to Autozone to read code it threw after changing out IACV, Got a P0171 Bank 1 System is too lean.

In addition to the new IACV, fuel pump, and fuel filter, have cleaned out the throttle body, not too bad but definitely got some junk out of it. Think in one of its previous lives it was a company trunk in a pretty dusty environment. New air filter and 1/2 way through new plugs, replaced the exhaust manifold side.

Would love to help my son get his first vehicle running!! All help appreciated Thanks!!

 

Welcome to the forum

Clean the MAF sensor, once a year, they get dirty and under report air flow so you get Lean code.

Upstream O2 sensor lasts about 100k miles, O2s use chemical reactions to detect Oxygen in exhaust, so they do wear out(run out of chemicals) just like a battery does.

Vacuum leaks, free and simple test
Warm up the engine to operating temp, just below 1/2 on gauge, above 1/4
Let engine idle, probably about 700 on 1996 4cyl manual trans
Unplug the 2 wire connector on IAC Valve, valve will close all the way
Engine RPMs should drop to about 500 or so, or engine may even stall, either is GOOD, no vacuum leaks

If idle stays high then there is a leak somewhere or previous owner has messed with anti-diesel screw on throttle linkage.
A Fuel injected engine can not use an idle screw of course, no jets, but there is an anti-diesel screw on the throttle linkage that "looks like" an idle screw.
If mis-adjusted it can change engine operating because it also changes Throttle position sensor(TPS) voltage along with air flow.

Engine computer does need to re-learn some settings after battery is disconnected, just like radio presets are lost.
But that should only cause a wandering idle, maybe, for the first few drive cycles, not rough running.

So what this symptom may mean is that factory parameters for stock 2.3l engine, what computer uses after "reset" are not correct for current engine status, so something in the engine is out of spec, which could be vacuum leak or MAF sensor is dirty.

Also on any fuel injected engine run a can of Seafoam, or similar, injector cleaner in the gas tank once a year, it does help keep injector tips clean.


Last test
On cold start, without touching the gas pedal, engine should start up and REV to 1,500+ RPMs, then drop down to 1,100 or so, computer is in Choke Mode, running engine Rich with high idle
Then as engine/coolant warms up idle will start to drop down to 700 or so when fully warm, and computer will Lean out mix and use O2 sensor.

The REV up is because IAC Valve is fully opened when you first turn on the key, and it stays open all the way until RPMs are above 400(engine started), then computer starts to close it to set "target" idle, target is based on Coolant temp

Coolant temp comes from ECT sensor, this is a separate sensor only used by the computer.
Dash board temp gauge uses an ECT SENDER, they look similar but are not the same electrically.

Coolant temp sensor could be telling computer engine is always warmed up even when it is cold, this would make for hard cold starts(no choke mode) and stalling until engine warms up

The 2.3l Lima engine(1983 to 1997 Rangers) needs a 190-195degF thermostat, 205degF in colder climates, operating temps of engines should be above 190degF for best MPG and cleanest oil, burns off contaminants.

2.3l duratec engine, 2001 and up Rangers uses a lower radiator hose thermostat, often 180degF, which keeps upper engine at the 190-200degF level, so don't confuse the two engines

 

Thanks RonD!! I have cleaned the MAF already but will give it another shot. Also there is another sensor (what looks like hot wire anemometer, flow sensor) in the air intake nearer the throttle body. Cleaned it too but haven't looked up yet what that is for or if it can impact significantly how the vehicle runs. Also put in can of Seafoam but have not run entire tank out yet so may still be part of the problem. Will repeat treatment with next tank. Don't know how well truck was maintained in the past so think I will go ahead and change out O2 sensors because most likely need it anyway. Will pay more attention to rpms on startup and see if maybe that tells me about coolant temp sensor. Another symptom it's had is that on a few occasions after battery disconnect and not being able to get it started and one time when my son stalled it when taking off, seems to have gone into a flooded condition. Had to pull the fuel pump relay, have him start it and put it right back in within a few seconds to get it started. Any chance any of this could be related to bad (clogged) catalytic converted. Could back pressure be causing issue with EGR? Appreciate the help and will see what I can do after work today and update my post.

Thanks!!

 

I would do some basic diagnostics on this truck just because it seems like you purchased a non running truck.

Start with a good compression test, fuel pressure test, and vacuum leak test.

I doubt compression is the issue yet it is easy to check while doing the spark plugs.

Personally I would want to know the engine is in good shape before wasting time and money.

When you changed the fuel pump did you drain and flush out the tank or at least peak inside to check for debris, water etc in the tank?

Good luck with the repairs.

 

Based on the way it was running and runs when it settles out (other than loss of power on the up hills) I thought that overall the engine was sound and gears and clutch seemed good. Should be easy enough to check the compression and can hit Autozone for the fuel pressure test equipment even with the new fuel pump just to double check. Easy enough to do just to make sure its not part of the issue. During loss of power on the uphills I get better response out of it if I ease off the gas some. Bogs down worse when I put the peddle to the floor. I did inspect the fuel tank when I changed out the fuel pump and it looked good and filter on pump looked good. In addition to the SeaFoam I added a bottle of Heat to the tank also. Really just trying to see if I can figure out what might be the next thing to go after based on whats its doing. Was home at lunch today and started it up got similar behavior. Started up but could barely stay going. Stumbles all over itself. If I get it to hang on can get it to smooth out and run smooth at higher rpms. But even if I try to hold it at a fast idle it starts to stumble and fade no matter what I do until its missing all over the place and crashes. If I keep restarting it can finely get it to hold on and then get it to the point where it smooths out and I can drive it around (today the idle stayed up very high even once I got to the point of driving around). So it just seems to me that I have a sensor or component that is causing the ECM to lose control! What I don't know enough about is if the symptoms make something more likely that I can chase or if something like a bad injector can cause O2 sensor readings that cause the problems. Checked for any gas or gas odor in the fuel pressure regulator and found none and don't think that it would be causing the problems I am having. Also found some guidance on checking the timing / timing belt so will take a look at it just to make sure.

 

For now keep it simple check the basics.

you have a old truck, I am willing to bet you have several things wrong causing the issues your having.

Basic diagnostics will force you to get to know the truck better.

Just like when you go to the doctor for help with health issues your doctor will never just hand you a prescription without checking your blood pressure, send your blood out for testing and perform other basic test, a vehicle is no different.

I agree with RonD you may have a bad sensor yet to diagnose it properly a pin point test for the Code or codes you have will have to be done after you know the engine is sound fuel pressure is good while cranking, while running and while sitting with the engine and key off.

Plus if you have a bunch or just one vacuum leak that will need to be sorted out before getting too technical.

If you have lots of money and time to burn you could be like many other people that get lucky and start hanging parts but I am guessing this old truck will require any money that is spent on it, be spent on items that make this truck safe for your son and not wasted on a part that may have been good and may outlast the truck.

I have been spoiled when it came to troubleshooting older vehicles in the past because I had a complete engine analyzer and other diagnostic equipment that would electronically indicate what could be wrong that would be confirmed with a manual test.

For example I had a Sun MTS 4000 that could do a power balance if it showed a problem On one or more cylinders I would immediately do a compression test on those cylinders if the power balance also showed that I had spark, fuel and air to those cylinders.

Without having a large scale diagnostic machine this means more manual testing even if you do not think the test would reveal the problem your tracking down.

 

I agree and will do my best to step through things one at a time. Good advice when you get anxious and just hope to stumble upon the answer. Will start backtracking on a few things I've already looked at or done (re-clean MAF, check for vacuum leaks, and do fuel pressure, etc) and will also check compression. I'll keep reporting back as I get the opportunity to work on it. I sure have benefited from folks that have a whole lot more experience then I do at this so hope that I keep getting the Help!!

 

I am positive you will get any help you need or desire, RonD and others here are some of the most helpful and knowledgeable people I have encountered on any forum.

I do what I can for people but I am always less likely to get involved when people come here for that tip towards the magic part that may or may not solve the issue.

I like it when I feel that I have helped the vehicle owner learn more about the vehicle they are working on.

I really like it when through proper diagnostics we all can know for sure the part installed because the part or parts were proven bad worn or otherwise defective.

I stress a compression test a lot because if the engine has low compression or a worn engine it is best to know that before even one dollar is spent.

Good luck.