Hard cold start bad gas mileage

[LOCKONS7RA7US]

Hello everyone so lately I have been having trouble with my 92 x eddie bauer edition. When I start it up cold it it kicks over fine and runs and idles but after 2-3 mins then it starts to lower the idle then starts to bog until it cuts out and kills the motor. I'll restart it and will be fine but then restart the lower idle and boging . I step on the gas while it's boging and after 1-2 mins holding the gas pedal at 2k rpm it will be fine sometimes I have to do it longer. When it's warmed up then runs fine like nothings run with it but if I leave it sit for more then 3 hrs then I have to go through all the bullshit again. I have also noticed to that I get bad gas mileage I barely make 200 miles a tank .
I've done the all sorts of research and replaced alot to no success

So far

Mass air flow sensor
Air filter
Mass air flow unit / metal housing
Top radiator hose
Bottom radiator hose
Thermostat
Coolant temp sensor
Coolant temp sender
Throttle position sensor
Idle air control valve
Pcv valve
Air intake temp sensor
Eec relay
Fuel pump relay
Wot relay
Pcm
Fuel filter
Spark plugs
Spark plug wires
O2 sensor

Soo that being said I may be missing a few things but im just lost at this point In regards to what it can be please help

 

[natenkiki2004]

A lot of that stuff is tune-up worthy but I can't believe you replaced the PCM without looking at basics first. Vacuum leak would be my first thought. The small plastic lines love breaking and getting holes worn in them. Quick and dirty, unplug all your vacuum lines and cap the "tree" off. Start it and see if it behaves different. If it does then you need to trace which vacuum line is problematic. If not, hook it back up and look elsewhere. I'd suspect another air leak, either in the intake tube or intake manifold.

 

[LOCKONS7RA7US]

I've looked at the basics even replaced the o2 sensor changing the pcm was s last resort . Thst didn't work but it is what it is . I can go abouts checking for a air leak again but I've already checked the air intake tube for leaks and nothing . And for your other basic intake manifold I've checked that as well by hosing it down around the gasket area with brake cleaner and it didn't affect a thing if there was a leak then it would have made it self present but nothing out of everything I thought it would be a air leak like you said or fuel related

 

[2stroke]

Coolant temp sensor

 

[natenkiki2004]

Coolant temp sensor

This. Not sure why I didn't notice it missing from the list.

 

[LOCKONS7RA7US]

It was there I just miss labeled it . When I flushed the coolant in august I replaced top n bottom radiator hoses thermostat , coolant temp sensor and the coolant temp sender .

 

[FR-425]

Let me guess, No CEL?

 

[LOCKONS7RA7US]

This might seem like a retarted question but what is that ?

 

[FR-425]

Check Engine Light

 

[LOCKONS7RA7US]

#### I'm retarded sorry should have realized it no there's no check in the engine light comes on

 

[FR-425]

Is that a yes or a no?

 

[LOCKONS7RA7US]

There's no check engine light .

 

[FR-425]

Okay, great news not
I suspect that the only two parts you haven't replaced are the problem.

Crankshaft Position Sensor and the Ignition Control Module.

 

[FR-425]

Unless the engine is just shot and has very low compression.

 

[LOCKONS7RA7US]

Well damn can only replace one at a time and see what happens..

 

[FR-425]

start with the CPS, if the ICM is ok you'll know right away.

 

[LOCKONS7RA7US]

Okay well I have a question I have replaced the ICM and to no avail . I then ran the code reader to see if anything will come up . I got the code 21 engine cooling Temperature out of range . But I have already replaced it . Why do I keep getting that code if I replaced it ? And it was the only code I got. And if the crankshaft position sensor was bad wouldn't I get a code ?

 

[natenkiki2004]

Okay well I have a question I have replaced the ICM and to no avail . I then ran the code reader to see if anything will come up . I got the code 21 engine cooling Temperature out of range . But I have already replaced it . Why do I keep getting that code if I replaced it ?

Aftermarket parts can be made poorly or be DOA. Test it with a multimeter and be sure. If it tests fine then the wiring must be bad. Just because you get a code for something, doesn't mean that part is bad. Like getting an O2 sensor code. Doesn't mean the O2 sensor is bad, maybe the engine really is running straight lean. On the other side, it's possible that the sensor is stuck or that the wiring is bad.

And it was the only code I got. And if the crankshaft position sensor was bad wouldn't I get a code ?

Not on a 1991/1992 that I know of. If the crank sensor drops out, how is the computer supposed to know if you shut the engine off or the sensor/wiring failed? On these primitive setups, the computer can't tell if the sensor reading drops due to a stall, seize, lack of fuel, broken sensor, broken wiring, loss of spark... on and on. If the crank sensor drops out, the computer can't tell when to fire fuel/spark so the engine dies. Then the computer knows that something happened because the RPM is gone so it illuminates the Check Engine light (notice it's on before you turn the key or if you've ever stalled the engine). But it doesn't throw a code because it can't possibly know what caused the RPM signal to stop in the first place.

It could, in theory, throw a code on a 1993/1994 due to the camshaft sensor. If the cam is still going but the crank isn't, the computer should know the engine is still spinning and something happened with the crank. It may still die due to timing but it can at least throw a code, again, in theory. I don't know how the later years are programmed.

 

[FR-425]

Okay well I have a question I have replaced the ICM and to no avail . I then ran the code reader to see if anything will come up . I got the code 21 engine cooling Temperature out of range . But I have already replaced it . Why do I keep getting that code if I replaced it ? And it was the only code I got. And if the crankshaft position sensor was bad wouldn't I get a code ?

That always gets us scratching our head. replace Coolant sender and still have the same problem.

You didn't mention you still have code 21. That's the key info here.

Like Nate said, "new" doesn't mean spit anymore. May even be just the wrong part.

Get another "new" ECT

On the CPS you won't get a code other than spout open/short. IF the ICM is good. However if the the CPS is open/short you will have a no-start situation. If the CPS has an erratic, weak, or intermittent signal you will get codes 14 or 18, again only if the ICM is good..It's an unfortunate oversight that there is no fault detection for the ICM itself. Nice one Ford! This really should have been a programming recall. I guess this was the trade-off for "limp mode" as a failed ICM will not prevent the engine from running but rather use a base-line ignition scheme of the "fall back" circuit in the ICM.

I have learned that when this happens you should get code 998. "operating in failure mode" but this only occurs once and if cleared i.e. dead or disconnected battery it will not repeat the code 998. fun stuff!

 

[malohnes]

In the past week a couple thread post issues were resolved due to wiring harness issues, not component failures. Sometime the component may be old and original but still functioning correctly and the real culprit is the wiring to or from the component. Thats also part of the journey in solving these issues of our old trucks. Im finding more and more cracked and falling apart connectors every time I work on my truck.