clean the oem injectors on my own vs aftermarket new ones? (1995 305) Core($) on an injector??

Schurkey your replies are spot on, especially the last one...

[Elvis Voice]Thankyew, thankyew verra much.[/Elvis Voice]

DerekTheGreat said:

...EDIT: Last year I swapped in a rebuilt injector pod assembly like this one here. I'm pretty sure I didn't pay that much. Can't remember if I bought it from that seller either, but there is at least a $50 core return. Even with my bum O2 sensor, my truck does run smoother and picked up a couple tenths in the MPG department. New heated O2 sensor to commence in my truck at some point in the future.

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I had the "bum" one wire O2 sensor replaced about two weeks ago with the three wire, heated unit I bought. There was also a wiring harness adaptor I bought to help make the swap easier. I made my splice based off information caman provided, straight off the 4x4 circuit. I did it right behind the fuse block, was a major PITA for me. Ran the ground wire up to one of the clutch master cylinder bolts, perfect fit and almost impossible to see.

I haven't had my scanner hooked up to it in two weeks, but the heated unit DOES NOT go into closed loop at idle as some had previously thought it might. I'm still only seeing about 4 cross counts tops- bum sensor #2? I did verify that I've got battery voltage up to the heater, not sure how to verify that it works, but I think it does.

Worth noting that swapping the O2 sensor was a necessity. A week or so leading up to the swap and the thing had zero power at full throttle, not sure how it ran without backfiring or sputtering or pinging like mad. Would only set the code (13 IIRC?) for "Lean limit reached" if it sat and idled. To which my dumbass assumes it is trying to lean the mixture and that's as far as it can go. Which is a big mystery to me as the scanner shows it's in open loop when it sets the code. With the new, heated sensor in place power has been restored. Code reappeared once and hasn't since. Even though it says it's in open loop at idle, it sure doesn't smell as rich as it once did at idle. Solved some quirks it had too, overall a worthwhile upgrade.

DerekTheGreat said:

I haven't had my scanner hooked up to it in two weeks, but the heated unit DOES NOT go into closed loop at idle as some had previously thought it might. I'm still only seeing about 4 cross counts tops- bum sensor #2?

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Does it go into closed loop while driving?

Yes. It's strategy for closed loop operation hasn't changed. It wants to go into closed loop after about five minutes of run time and will pop out under 1000 RPM at 0 MPH. I have yet to determine if it goes into closed loop if moving, disregarding engine speed.

DerekTheGreat said:

Yes. It's strategy for closed loop operation hasn't changed. It wants to go into closed loop after about five minutes of run time and will pop out under 1000 RPM at 0 MPH. I have yet to determine if it goes into closed loop if moving, disregarding engine speed.

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All this talk lately about different diagnostic modes on various scanners was making me wonder if it had anything to do with that. Like the 10k mode will bypass closed loop ....but I think it also jacks up idle to 1k rpms too...Really don't know...just thinking out loud

I'm not sure my MT2500 has any other mode. There is a "Test Drive" feature (Which I use when I am planning to drive it to investigate) and then there's a "Read Codes" or "Read Data" option which will make the thing hold 1000 rpm. Test Drive mode seems undistinguishable from normal operation, only I've got the scanner and all the cables in the cab.

I had suspected closed loop operation is determined from the factory, that changing the O2 sensor wasn't going to change that. However, I had no way to prove this theory (Like many of my others) and so had to do it for myself to get the definitive answer. Much like all the questions I have regarding diagnosing the F-150 I'm working on. Made a thread within some Ford truck forum, got some feedback, but now I'm at a standstill short of testing those theories. Which is leading me somewhere, it's just taking a while.

I don't know about YOUR model-year vehicle, but my '88 K1500 5.7L is claimed in the Emissions/Fuel service manual to stay in closed-loop at idle even with the single-wire OEM O2 sensor.

Pretty sure the 305 is supposed to, too. I don't remember about the V6; and I'm thinking that the 7.4L does NOT stay in closed-loop at idle.

That said, my '88 would drop out of closed loop at idle at a stop sign, but be back in closed-loop before I was half-way across the intersection once I was actually moving again. The O2 sensor was no spring chicken.

I put in a heated O2 sensor, but haven't really checked operation since then.

Schurkey said:

I don't know about YOUR model-year vehicle, but my '88 K1500 5.7L is claimed in the Emissions/Fuel service manual to stay in closed-loop at idle even with the single-wire OEM O2 sensor.

Pretty sure the 305 is supposed to, too. I don't remember about the V6; and I'm thinking that the 7.4L does NOT stay in closed-loop at idle.

That said, my '88 would drop out of closed loop at idle at a stop sign, but be back in closed-loop before I was half-way across the intersection once I was actually moving again. The O2 sensor was no spring chicken.

I put in a heated O2 sensor, but haven't really checked operation since then.

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Hmm. Your '88, is it an automatic or manual transmission? I wonder if that's what the difference is.

That is about how my truck acts, only it's in closed loop again as soon as I start moving or any time the RPM's hit or exceed 1,000. Now that I'm thinking about it, there might be an issue with my TPS, as even at WOT it doesn't pop out of closed loop and I'm under the impression these are supposed to.

Shouldn't I have seen an increase in O2 sensor cross counts? Thought I read somewhere that above 20 is a good number. This new one doesn't report any higher than the old one- best I've seen is 5. Don't know if they break-in or anything like that. I last had the MT2500 hooked up before the wife and I took the thing all over West Virginia, so that was about two weeks ago now.

Yes, my '88 is an automatic.

Sensors require no break-in, and yes, I'd expect higher cross-counts.

Exhaust leak--broken manifold, failed gasket?

What are your fuel trims and fuel pressure?