CEL on and using ALOT of gas..Help

[tbrracer]

Ive read and searched post for days but with no luck...93 Ranger 4.0 automatic 200,000 miles. The CEL light will come on mainly like crusing speed like less then 1/4 throttle, and when the light is on I get HORRIBLE gas mileage! If i speed up like above 1/4 throttle usually the CEL light will go off like if i drive fast basically I have done plugs, wires, new vacum lines, fuel filter,fuel pump,o2 sonsors both of them, new air filter also. Please any help or ideas would be greatly appreciated if theres things to test or try please let me know and Ill try them like use to get around 20 mpg on average no get about 9-10mpg

Im not afraid to search and read and have, or to test things on the truck just and a dead end and need a new set of ideas!

Thanks

 

[ab_slack]

Try and get a code out of it, that should help narrow it down quite a bit.

 

[tbrracer]

Duhh sorry my bad i pulled most of the codes amd they werr transmission codes but i.will repull them and post them thanks

 

[tbrracer]

Ok tried pulling codes but not sure if these are right

code # 12
# 2
# 15
# 7
# 17
# 18
I dont think the single digit coded are coorect as the codes should be two digits right?

Any way to post a video to get some help on the codes?
Thanks

 

[ab_slack]

I am far from being particularly knowledgeable, much less any sort of expert, and there are some really good one here, but since this thread has been quiet, I'll chime in again and if I say something stupid enough someone will chime in with good info

The fuel economy is really terrible. That is pretty radical.

As I said a code will help, but you mentioned transmission codes and that got me wondering about the symptom that it only appears over 1/4 throttle. From my experience, things in the engine such as sensors or conditions that don't cause the engine to run right are much more persistent.

So transmission codes, maybe the problem is with the transmission? Maybe the engine is running but only some of the power is getting to the wheels? If energy loss in the trans were that bad I would think it be getting hot.

Here is where a little info can be dangerous and maybe I am saying something incredibly stupid. Lots of extrapolation here. Automatic trans, even back then, would lock into gear, between gears the torque converter would be handling the load, but that is lossey (hence the lock). If something wasn't right, it couldn't lock, the power delivery might be inefficient.

If it is trans, I can't offer anything other than to say check trans fluid.

Do you smell fuel when it is off? Just thinking fuel leak, not related to engine or trans.

Back to the engine, do you smell fuel when it is running or is it making lots of smoke? And how does the engine sound? Does it seem to run rough or miss? Low power? With such bad fuel economy I would expect some obvious running problem other than fuel economy.

Now if it is the trans, that might seem like low power cause acceleration is poor, but maybe what is happening is engine RPM goes up but the transfer to the wheels takes longer. I don't know.

Just trying to toss ideas out there. Good luck.

Andrea

P.S. Your codes post came up while I was typing this, I am sure someone can make something from it.

 

[tbrracer]

Well thanks for th reply, when the cel is on the truck idles ruff like when at a stop sign , and if im sitting in traffic or stopped for lil while yes a i can deffinalty smell unburnt fuel like its running really rich, and if im on the freeway or open road and give it full throttle it will run a lil ruff for a second or two then you can see black smoke come out the exhaust like alot of carbon built up from running so rich! , no spillt gas or fuel leaks, but yes it does run ruff when cel light is on, and then all the sudden the light will go off and run smooth as silk!!! and i usually commute about 40-50 miles round trip and it takes me 5 gls of gas which is usually 1/4 tank which is about 9-10 mpg and i use to go 90-100 on a 1/4 tank of gas which is about 20mpg and very few days now the light will stay off my morning communte to work and the gas needle will barley move like the truck is running right but the days a very few that the light stays off much anymore

 

[ab_slack]

This is for a 94, not certain if the same.

http://autorepair.about.com/library/a/1i/bl804i.htm

I never have done it myself. My B2 doesn't have CEL and my explorer has OBD2.

I think they are three digit codes as per here.

http://autorepair.about.com/cs/troubleshooting/l/bl_dtcs_54a.htm

 

[tbrracer]

This is for a 94, not certain if the same.

http://autorepair.about.com/library/a/1i/bl804i.htm

I never have done it myself. My B2 doesn't have CEL and my explorer has OBD2.

I think they are three digit codes as per here.

http://autorepair.about.com/cs/troubleshooting/l/bl_dtcs_54a.htm

Im gonna try to find auto parts store that can pull the codes for me tommorow so ill post my results

 

[ab_slack]

Looks like I may have given you some bum information. Here is another link.

http://www.extreme-check-engine-light-codes.com/Ford OBD1 Decoder.htm

That uses a light instead of a meter to look at codes and it shows two digit codes.

 

[RonD]

There are only a few main sensors that control gross fuel/air mix, O2 sensors are for fuel "trim", fine tuning the mixture, these can reduce MPG but not by a lot.

The MAF(mass air flow) sensor tells the computer the amount of air coming into the engine, also the temperature of that air(colder air requires richer mix than warmer).

The MAP(manifold pressure) sensor, most engines don't have both MAF and MAP but some did, the MAP tells computer if engine is under load and fuel is adjusted accordingly.

TPS(throttle position sensor), this tells the computer where you foot is on the gas pedal, computer adjusts fuel mix accordingly.


One often over looked thing when mileage goes to sh!t, is the FPR(fuel pressure regulator), this is a vacuum operated device, so if it's diaphragm leaks the raw fuel is sucked into the intake and floods engine.
Easy to check though, FPR is on the fuel rail, it will have a vacuum line attached, remove this line and smell/check it for fuel, there should be no smell of fuel there.

Injectors can get stuck open, dumping in fuel all the time, with engine at idle use a small hose as a stethoscope and listen to each injector, should have a steady "tick, tick, tick" as it opens, no tick or intermittent tick means time to replace or clean.

Injectors also work by Grounding, when key is on injectors all get 12 volts but no Ground, so stay closed.
The Computer Grounds the injector to open it, if this grounding wire to the injector gets a bare spot and grounds to something then injector is open all the time

 

[tbrracer]

Thanks for.the info i will check out what you suggested today


[/B]

There are only a few main sensors that control gross fuel/air mix, O2 sensors are for fuel "trim", fine tuning the mixture, these can reduce MPG but not by a lot.

The MAF(mass air flow) sensor tells the computer the amount of air coming into the engine, also the temperature of that air(colder air requires richer mix than warmer).

The MAP(manifold pressure) sensor, most engines don't have both MAF and MAP but some did, the MAP tells computer if engine is under load and fuel is adjusted accordingly.

TPS(throttle position sensor), this tells the computer where you foot is on the gas pedal, computer adjusts fuel mix accordingly.


One often over looked thing when mileage goes to sh!t, is the FPR(fuel pressure regulator), this is a vacuum operated device, so if it's diaphragm leaks the raw fuel is sucked into the intake and floods engine.
Easy to check though, FPR is on the fuel rail, it will have a vacuum line attached, remove this line and smell/check it for fuel, there should be no smell of fuel there.

Injectors can get stuck open, dumping in fuel all the time, with engine at idle use a small hose as a stethoscope and listen to each injector, should have a steady "tick, tick, tick" as it opens, no tick or intermittent tick means time to replace or clean.

Injectors also work by Grounding, when key is on injectors all get 12 volts but no Ground, so stay closed.
The Computer Grounds the injector to open it, if this grounding wire to the injector gets a bare spot and grounds to something then injector is open all the time

 

[RonD]

This is a good web page to book mark
http://oldfuelinjection.com/?p=10

Tells about how to test sensors and what each does and doesn't do.

One BIG thing to remember about sensors and the computer, the computer doesn't "know" when you change or adjust sensors, so you must ALWAYS tell the computer to check for any changes................
But pretty easy to do that, disconnect negative terminal on battery for at least 5 minutes, on reconnection computer will reboot and look for any changes.

So if reading a step by step "How-To" the first Step should be......disconnect battery, yes for safety, but also for the more practical "reboot" to see if changes help.

I am sure many have spent hundreds of dollars on new parts without disconnecting the battery, when the first $30 would have fixed it..........if they had only "told the computer"