Unplug Idle air control valve and engine dies (2.9L V6), Normal or bad valve?

[franklin2]

Why do you think I haven't replaced anything yet. I'm not guessing I'm checking things over first.

The distributor is new, and the module on the distributor is held on with 2 bolts, you don't have to tear it apart to change it. The TFI is a separate part just so happens that Ford put it in the worst place possible.

You are forgetting about the pickup module inside the distributor. It's just as important as the TFI module on the side of the distributor. And they do go intermittent and bad sometimes.

It's a well known fact among professional mechanics, the Fords with the EECIV are difficult to work on. When they work, they work great. When you start having problems, they are very diffcult sometimes to diagnose. Unless you have a breakout box, there is no way to get streaming data for troubleshooting.

 

[wildbill23c]

You are forgetting about the pickup module inside the distributor. It's just as important as the TFI module on the side of the distributor. And they do go intermittent and bad sometimes.

It's a well known fact among professional mechanics, the Fords with the EECIV are difficult to work on. When they work, they work great. When you start having problems, they are very diffcult sometimes to diagnose. Unless you have a breakout box, there is no way to get streaming data for troubleshooting.

I'd hope the pickup coil isn't bad in a brand new distributor but haven't ruled out anything at all yet. Weird part now is, it does it shortly after taking off down the highway, then sorts itself out and runs find the rest of the trip....I figured a pickup coil, distributor, TFI, etc. would be causing issues constantly, or at least multiple times during a driving session, not just briefly after taking off then be fine for the rest of a 30+ mile trip at varying speeds LOL....and I thought the terrible attempt by Ford to try and computerize a carburetor on the 2.8L V6's was bad, I think these 2.9L V6's are worse when the electrical stuff doesn't want to play nice.

I got my fuel leak fixed with a new o-ring today. Took it out on a drive, about a mile down the road it started losing power again, let off the accelerator for a second then back on it again, did the same thing started losing power, let off the accelerator once again then back on it, and kept on it the next time it did it then it suddenly cleared up and ran fine the rest of the trip....it wasn't doing the usual bucking that was doing for a while...really wish I had all the fancy tools and test equipment to be able to more easily see what's going on while driving....a mechanical voltage gauge would be really nice, the amp meter in the dash is 100% pointless the needle never does move. When turning the heater blower motor from off to high during idle the engine immediately begins surging and won't recover until I give it some gas, then it will smooth itself out and be fine after that, same goes for turning on the headlights, doing so immediately will set the engine surging like its hunting for voltage rather I'm thinking the sudden current draw is pulling enough amperage that the alternator isn't responding at idle, as if it has a bad winding/field. The alternator in my Bronco 2 had a bad field in it but it didn't cause a surging issue it would just barely maintain 12 volts...I'd guess that it is possible the alternator is bad, I swapped the battery out of my Bronco 2 into the Ranger just as a way to rule out a battery issue, same results. The alternator is the original, and its kind of noisy, like a metallic scraping noise while its spinning. It does have the regulator on the alternator, so possibly a bad regulator, or bad alternator, or both....more testing needed of course.

 

[Nez'sRanger]

I had quite the bout with my 2.9 last year as well... It was doing this crazy surging thing while cold... Let it warm up, and it ran half decent (albeit, rich, very rich).
I chased that darn problem for months... Multimeter tested every wire I could find, replaced several sensors, and after many trips to O'Reilly's, I broke down and grabbed a used harness off a scrapyard truck. I "restored" the harness, and installed it... Never had an issue again.
All that to say, while I was rebuilding the harness, I found the wrapping on the wire ends was shrinking, leaving exposed copper in close proximity to other wires and also to the frame. Especially under the fuse box, on the relay plugs. I would check out the ends of all your plugs.
It may be a dead end, but, it sure is easy to do!
Hope you can figure it out soon! These trucks are like army tanks when they're working right! Haha!

 

[wildbill23c]

I had quite the bout with my 2.9 last year as well... It was doing this crazy surging thing while cold... Let it warm up, and it ran half decent (albeit, rich, very rich).
I chased that darn problem for months... Multimeter tested every wire I could find, replaced several sensors, and after many trips to O'Reilly's, I broke down and grabbed a used harness off a scrapyard truck. I "restored" the harness, and installed it... Never had an issue again.
All that to say, while I was rebuilding the harness, I found the wrapping on the wire ends was shrinking, leaving exposed copper in close proximity to other wires and also to the frame. Especially under the fuse box, on the relay plugs. I would check out the ends of all your plugs.
It may be a dead end, but, it sure is easy to do!
Hope you can figure it out soon! These trucks are like army tanks when they're working right! Haha!

I'm thinking of similar issues as well, if the weather would just cooperate on my days off it would be great, sucks trying to do any troubleshooting in the rain. Exactly part of my plan is to go through all the wiring and check everything over, as I have a feeling there may be some wiring issues too.

 

[franklin2]

I'd hope the pickup coil isn't bad in a brand new distributor but haven't ruled out anything at all yet.

If it's a rebuilt Cardone, It very well could be bad. Brand new I would have my doubts also.

 

[wildbill23c]

If it's a rebuilt Cardone, It very well could be bad. Brand new I would have my doubts also.

Double checked, distributor is Motorcraft.

 

[franklin2]

Double checked, distributor is Motorcraft.

Cardone "rebuilds" Motorcraft distributors. I use the term "rebuild" loosely. If you got a brand new distributor from the store, great. If you got a rebuilt distirbutor, it can be iffy. With some of these odd engines, Cardone is the only game in town, you don't have much choice no matter where you shop.

 

[wildbill23c]

Cardone "rebuilds" Motorcraft distributors. I use the term "rebuild" loosely. If you got a brand new distributor from the store, great. If you got a rebuilt distirbutor, it can be iffy. With some of these odd engines, Cardone is the only game in town, you don't have much choice no matter where you shop.

This raises even more questions, however a search on Rock Auto does show Cardone, and Motorcraft with different part numbers and different prices, so I'd think given the ridiculous price the shop charged me that they must have got the real Motorcraft distributor LOL...

Is there a way to test that pickup coil while its installed?

 

[franklin2]

This raises even more questions, however a search on Rock Auto does show Cardone, and Motorcraft with different part numbers and different prices, so I'd think given the ridiculous price the shop charged me that they must have got the real Motorcraft distributor LOL...

Is there a way to test that pickup coil while its installed?

It's tough to verify it's bad, since it works 90% of the time. Usually it misses a few pulses or flakes out for a short period of time and then starts working again.

 

[PetroleumJunkie412]

Best way to check your hall effect sensor (one in The distributor) is disconnect spout and check base time. If you have Swiss watch precision with your base time, sensor is good. If you walk around a bit with the SPOUT connector pulled, bad hall effect sensor.

 

[wildbill23c]

Best way to check your hall effect sensor (one in The distributor) is disconnect spout and check base time. If you have Swiss watch precision with your base time, sensor is good. If you walk around a bit with the SPOUT connector pulled, bad hall effect sensor.

I'll see what's going on this weekend, hoping its more simple than a distributor dissection LOL. A mechanic friend of mine is leaning towards clogged fuel injectors? Wouldn't that cause the thing to have low/loss of power all the time though? Lately I've been able to drive it around most of the time at up to 55mph for long periods of time without issue...I took it out on a different highway the other day that has a 65mph speed limit and the issue resurfaced again....I'd think clogged or otherwise misbehaving fuel injectors would cause the same issue regardless of speed? Maybe not?

 

[RonD]

I'll see what's going on this weekend, hoping its more simple than a distributor dissection LOL. A mechanic friend of mine is leaning towards clogged fuel injectors? Wouldn't that cause the thing to have low/loss of power all the time though? Lately I've been able to drive it around most of the time at up to 55mph for long periods of time without issue...I took it out on a different highway the other day that has a 65mph speed limit and the issue resurfaced again....I'd think clogged or otherwise misbehaving fuel injectors would cause the same issue regardless of speed? Maybe not?

Assuming level ground, more fuel is needed at 65mph than at 55mph so lower fuel pressure, or lower injector flow could account for that

The computer adjusts the open time for injectors based on O2 sensor feed back
Computer assumes 30psi fuel pressure, there is no fuel pressure sensor
If O2 starts to show Leaner burn computer opens injectors longer to get richer mix
In theory if open time gets too long the computer should set a lean code, but if its just at highest fuel demand, above 65mph then it may not

 

[PetroleumJunkie412]

Assuming level ground, more fuel is needed at 65mph than at 55mph so lower fuel pressure, or lower injector flow could account for that

The computer adjusts the open time for injectors based on O2 sensor feed back
Computer assumes 30psi fuel pressure, there is no fuel pressure sensor
If O2 starts to show Leaner burn computer opens injectors longer to get richer mix
In theory if open time gets too long the computer should set a lean code, but if its just at highest fuel demand, above 65mph then it may not

Stay calm, this is a thread jacking.





So... Special circumstance question for you Canadian God, since we're on the subject of injectors, and since WildBill did ask about MS...

With Megasquirt, the Volumetric Efficiency is calculated from Wideband O2 readings; the computer adjusts the VE map to in turn change injector pulsewidths in order to match the AFR table the user programs. Slick system, and gives a very good idea of engine performance at a glance.

My FPR died on me over the summer, so I disconnected it and I let the computer remap around having a significantly higher fuel pressure I could get a new one. This changed my AFR tables significantly, but I noticed no difference in running from the butt dyno or from datalogs.

As of right now, I'm working on the Turbocharger install. I had considered getting a rising rate FPR to make up for the boost pressure affecting fuel regulation, but I'm a cheap b*stard, and havent purchased one yet.

Knowing that I can get the system to make adjustments based on a lack of variable fuel pressure, would it make sense to you to run without a FPR, and to let the system make VE and fueling adjustments knowing I'll have a consistent fuel pressure and volume on a return system?

Have a Kemso 340 LPH pump in the tank ($34 on eBay, and they allow the deletion of the rail pump - really need to write that article as well...). Supplies 340 liters of fuel per hour at 43 psi, so pressure and volume shouldn't be a problem...

My concern is if removing the FPR from the system would cause lean issues; I know I'm going to knock a 93mm hole (or six) in my oil pan eventually, but I'd rather it be from a 3.0 going through my intake, and not from burning lean...

 

[RonD]

Well the FPR only uses vacuum assist at idle, high vacuum, once vacuum is gone, i.e. boost added, its running at 43-45psi pressure, the FPR's max rating, and would hold that pressure until pump couldn't provide that much, lol

When you say you disconnected FPR you mean you blocked the return, right?
Which can be hard on the pump, since its always on and wants to pump the same max volume all the time, which is the point of the FPR being used, its not just for the computer, although having a stable fuel pressure will make calculating AFR much easier, lol, and its why there is vacuum assist on the FPR
Its also there so the pump can run at max volume without too much back pressure, the extra just goes back to the tank

You could do similar to a 1998 and up setup and put return line and FPR between fuel filter and tank, the 3 port filters, but Ford put the FPR in the tank on those assemblies, but no reason you couldn't do that on the return line, outside the tank
Although just having FPR on the engine as it is now would be easier

Not sure why you would need a variable FPR(well more variable than the stock one), unless your pressure is dropping too much at WOT and full boost, but it shouldn't with 340 LPH
Never looked at the diaphragm setup in the FPR so not sure how it reacts to positive pressure, boost, but a check valve on that vacuum line would take that off the table

 

[wildbill23c]

Assuming level ground, more fuel is needed at 65mph than at 55mph so lower fuel pressure, or lower injector flow could account for that

The computer adjusts the open time for injectors based on O2 sensor feed back
Computer assumes 30psi fuel pressure, there is no fuel pressure sensor
If O2 starts to show Leaner burn computer opens injectors longer to get richer mix
In theory if open time gets too long the computer should set a lean code, but if its just at highest fuel demand, above 65mph then it may not

Hmm, ok, so I could also have a malfunctioning O2 sensor as well. To me when I start it and its just sitting there idling as its warming up, to me the exhaust smells of extra fuel (too rich), but the O2 sensor doesn't play any role during warm up of the vehicle though correct? The O2 sensor only is functioning once the vehicle is at operating temperature?

I'm still kind of on the path of one or more fuel injectors could be clogged, worn, etc....so replacing them would probably be a good path to take anyways since the vehicle sat with old fuel in it for 4 years, I'd think replacing them would make far more sense than trying to clean 30+ year old fuel injectors, and with all the work to remove them, I don't think wasting time cleaning them and finding that didn't cure the issue would be far more sensible to just replace with new injectors. I mean when I first got the truck the power loss at higher speeds was much, much worse, so possibly due to the large amount of fuel system cleaner and new fuel did a slight amount of cleaning of the injectors but not enough to clear them up enough to provide the proper amount of fuel for consistently higher speeds.

It still had about 3/8 of a tank of gas in it when I picked it up and was told the fuel in it was what it had when they quit driving it...they claimed they got a new car so the Ranger was just kind of tossed aside and left for dead practically it seems, as the owner had passed away and the family of course wasn't interested in an old truck, which was ultimately donated to a used car lot/thrift store company that didn't do anything just placed it for sale. So the buyer is left cleaning up what the previous owner/family members didn't do.

Since I'm not getting any codes but get a code 11 I assume the ECU is functional? I haven't really ruled out an ECU issue, but I'd think an ECU issue would be much more profound than just a high speed drive.

Sorry for all the dumb questions just trying to piece together what I'm slowly finding through testing, and hoping someone's had these issues before and/or much better ideas as to what's going on, course this is quite limited to the rest of you not being in the driver's seat.