Mysteryous bogging... '97 2.3

[lordkyleofearth]

Fabulous!

I'm so glad it worked. Congrats on your success, and good luck with the rest of the fuel lines & injectors getting cleaned out. But indeed, spray your IAC valve & the MAF sensor with carb cleaner. It WILL be needed.


Clean the carbon out form inside this:

http://www.explorerforum.com/photopost/data/503/3661iac_sensor_after_removing_black_cap.jpg
http://www.fordf150.net/howto/images/tbclean/10iac.jpg





Spray this sensor near your air intake filter:

http://fordfuelinjection.com/images/maf.jpg

Thanks for this too, I'll clean the IAC again soon (did it during the rebuild, but I think its crapping out again). I did the MAF the other day and was amazed by the layer of buildup on the elements.


I'm new to Boerne; I'm a native San Antonian. My fiancee just got a job in Kerville so its a nice half-way point. These hills make me want to get my MR2 back up and running more than the Ranger

 

[lordkyleofearth]

Did it again today. I got onto the highway and couldn't get over 55-60 mph. Lots of back firing when I was in the upper end of my possible range. I pulled over and disconnected the battery but the problem persisted. I cut off the ignition and then restarted the engine (which causes the O2 heater circuit CEL to come on) and everything was fine; drove like a champ.

Any ideas? The fuel filter and cleaning the MAF have helped, but whatever the underlying problem is, still remains.

 

[modelageek]

Did it again today. I got onto the highway and couldn't get over 55-60 mph. Lots of back firing when I was in the upper end of my possible range. I pulled over and disconnected the battery but the problem persisted. I cut off the ignition and then restarted the engine (which causes the O2 heater circuit CEL to come on) and everything was fine; drove like a champ.

Any ideas? The fuel filter and cleaning the MAF have helped, but whatever the underlying problem is, still remains.

do you have the OBD-II system? do you have a code reader? are you reading the codes? what # codes are you getting.........I would plan on doing a fuel pressure test. I bought a fuel pressure gauge at harbor freight for $20. you can borrow them. you can buy an actron gauge for $40

 

[lordkyleofearth]

It's an OBD-II system, it is only throwing 2 codes. I don't know what they are exactly (I think PO135 and PO141) but the readers list it as Bank 1 Sensors 1&2 O2 Heater fault.

Today it was bad enough that I couldn't get the truck over 35 mph. I ended up having to leave it in a parking lot

Lots of back-firing, idle became rough, I could only build up speed by slipping the clutch to lessen the load on the engine. The battery reset was not effective this time. I checked the timing belt to see if it was loose and it felt fine (tighter than the accessory belt).

Could a failing coil-pack be to blame? Is there any way that the timing could have slipped? I'm totally at a loss now.

 

[lordkyleofearth]

Since it is now backfiring heavily, the idle is getting progressively rougher, and the symptoms all seem to get worse the longer I drive it, is it possible that the timing belt is stretching or slipping? What would be the easy route to take in checking that?

 

[modelageek]

Since it is now backfiring heavily, the idle is getting progressively rougher, and the symptoms all seem to get worse the longer I drive it, is it possible that the timing belt is stretching or slipping? What would be the easy route to take in checking that?

I doubt it is the belt.....Codes would help? pull the vacuum line off the fuel pressure regulator and make sure there is no fuel in it.... if you can do a fuel pressure test that would help........if not run the truck shut it off and wait 5 minutes........cover the shrader valve with a rag and carefully relieve the fuel pressure.......

 

[AgPete139]

This couldnt all be caused by crappy O2 sensors, would it?

I'm really wondering why it's bogging so badly. If you have a small propane bottom, WD-40, OR soapy water...you can do this...

If you have the propane, open the bottle and put it really close near the intake manifolds. If you hear the engine keep a consistant idle in certain places, or if it surges in a good way back to normal with spraying the propane, then you have a gasket leak.

If you have WD-40, same method as above. Check the sound of the idling truck.

Using a spritz pray bottle, coat certain gasket areas with the soapy water. If you see a small bubble form or moving away from a certain spot, you may have a leak.

I'm wondering if you have a really horrible intake manifold gasket leak. This may also be aculprit.

Especially if it says Bank X is running lean.

 

[lordkyleofearth]

I already sprayed around in the engine bay looking for vacuum leaks; there aren't any. The truck is currently 'parked' at a hotel that was near where it broke down. Since I have no other vehicle it makes it hard to get out there and check things.

Friday I'm going to go check the fuel pressure to see if that is the source. I had a local mechanic suggest that the fuel pump may be failing and resulting in reduced pressure (which is why the problems only manifest under load or higher engine speeds where demand is greater). It also sort of explains why the problem is getting worse.

What pressure would be normal for a 97 2.3l?

 

[lordkyleofearth]

-Blast from the past-

I finally got a bit of time to play with the truck this weekend. The fuel pressure test and here are the results:

Key on, engine off pressure: ~36#
Engine running (reg hooked up): ~30# then climbs to ~38# as the vehicle sputters/dies
Engine running (reg disconnected): ~36#

If I gun the engine and try to keep it from dying pressure will drop to ~28# and then climb back to the high 30's low 40's.

I am not sure if the rise in pressure is from a bad FPR or if the rise is coming from the engine dying and lowering vacuum pressure ( I do not have a portable vacuum source to test with).

Any ideas?


*EDIT*
I have a video of the gauge during testing, I will upload it tomorrow while I'm at school and link it here.
Got it done early:
http://www.youtube.com/watch?v=uvbsspY5tBc


*2nd EDIT*
I did the test with the vehicle in neutral, I am now reading that I need to get a load on the engine for this to really be accurate (aside form idle conditions). I'll try a loaded test tomorrow. I'm also going to see if I can get an OBDII code scanner to check for any new CELs

 

[JC 97]

Did you check the egr for any blockages? I had a truck that acted the same and the vacuum line was plugged solid.I never had a fuel pump slowly die.They all seemed to just quit.

 

[lordkyleofearth]

I'll have to check the EGR port tomorrow. I ran the fuel pressure test again today, this time under load. Numbers are great. Truck drives fine (up to the top of 2nd gear ~40mph) without any real issue. There was a small hesitation at one point, but only momentarily and there was no change in fuel pressure when it happened.

I'm beginning to get really confused and frustrated here.