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Hesitation just off idle (and only in gear)

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ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Hi Dane,

This is the one I have. I’ve had it for a few years but have been using it more lately trying to get these last things closed off:

https://a.co/d/bi62gOr

I’m conflicted whether this is a valid theory since the KOEO seems to work well. It’s less traffic to analyze than KOER though. I’m almost wondering if there is a maybe a grounding issue on the EEC?

As a person at my work says, I am starting to look to “moonbeams” as theories…

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

grumpin

Re: Hesitation just off idle (and only in gear)

That’s the one I have and I’ve been happy with it.

I agree, could be a grounding issue, the EEC or the reader. This is aggravating.

I don’t remember, have you checked the wiring from the reader hook up to the EEC?

Does anyone you know have the same era Ford that you could check the reader on?

I use the reader on my Bronco and the 94 F250 I used to own.

Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold
1992 Bronco XLT 4x4 351W E4OD
1998 GMC Sierra SLE K1500 350 4L60E
Arizona

Gary Lewis

Re: Hesitation just off idle (and only in gear)

Administrator

That's a bummer to have the reader seemingly go bad in the middle of reading. At that point I'd use a test light to read the codes, as explained on the page at Documentation/Electrical/Electronic Engine Control (EEC).

But, I'd drive it a bit to see if it learns something, like it seems to have done this time. You've fixed a vacuum leak so maybe it takes it a bit to forget that?

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Yep, back to basics! Hopefully things are clearer with a test light.

A test light is coming tomorrow, but I’ll be on a work trip this week. (First one since COVID, and I was flying home on my last trip one day before international flights got shut down!)

I hope to post findings again next Friday or Saturday.

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

Gary Lewis

Re: Hesitation just off idle (and only in gear)

Administrator

Hope you have a good trip and then you are fresh when you get home and can sort out the problems.

Gary, AKA "Gary fellow": Profile

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

This post was updated on .

Thanks Gary, I'm back. It was weird to be back out into the world after three years at home... (mostly)

I fired up the truck in the garage and let it run for a good 10 minutes or so, just to give everything a little "stretch" and confirm the problems were still there.

I didn't take it on the road, but the stumble at high idle is there still. I confirmed also that if you kick the idle down, the problem is "gone". If you give some gas back to around 2000 RPM, the problem appears again.

It occurred to me that normally when I run the KOEO, the engine is cold. So, I ran a KOEO again after it was warmed up.

I got one code: 31. I had seen this before a couple years ago, but I replaced the EVP sensor and it went away. I ran the test multiple times - same code every time. There were a few continuous codes also, but I'll gloss over those for now. I also ran a KOER and got 31 on there first, along with a few others. I'm surprised that all of the sudden I have KOEO codes again, but if the ECM is going bad, then maybe it is not a shock.

I verified that there is 5VDC on the VREF line. I then backprobed SIGRTN to EVP, and it was tough to get a reading. At one point, I got .21VDC, but I have read it should be at least .25VDC. I then jumpered VREF to EVP, as I read that the code should change from 31 to 35. It didn't, it stayed at 31. So, I think this means I have more bad wiring all of the sudden (and I didn't touch that portion of the harness), or the ECM is on its way out.

The next recommended step is to take off the ECM connector and check for (lack of) continuity between pins 27/40, and 46/60. If there is, then it indicates an wiring issue. If it checks out, it means my ECM is bad (most likely?).

My ECM is behind the I/P, between the radio and instrument cluster. It looks like I can take the connector off to check the pins, but if that passes, how do I remove the ECM? Do I need to take the dash pad off? Or the whole thing (

) It looks like a bear to remove, and I think I remember some screws on the side between the frame that holds the ECM and the ECM itself?

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

Gary Lewis

Re: Hesitation just off idle (and only in gear)

Administrator

Glad you are back.

I don't know about the error codes, but I do know something about the ECU bracket. I posted about them in this post, but have copied some of the pictures over here.

There's a tab that holds the ECU in the bracket, which you can see in both of the pictures. In the left pic you can see the tab on the lower right of the right one. The left pic shows the front of the bracket and the right pic is the rear of the bracket. So you should be able to pull that bolt, remove the tab, and slide the ECU down.

Gary, AKA "Gary fellow": Profile

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

This post was updated on .

Thanks, I got it pulled out no sweat.

There is something small rattling around inside - maybe not a screw, but probably something that shouldn't be there!

If the wiring checks out, it looks like the Cardone reman unit is the most common/available. Any reason I should go somewhere else? Recommendations?

The ID number on it is E43F-12A650-Z1A

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

Gary Lewis

Re: Hesitation just off idle (and only in gear)

Administrator

I haven't found that # in the MPC. But I do agree that you shouldn't have anything rattling around in the ECU. I'd pull the cover and see what you can find.

Gary, AKA "Gary fellow": Profile

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Yep, that’s the plan tomorrow!

In the Fuel section of the parts catalog, my truck is either Calibration 376 or 409 (not sure which, the label on the valve cover is long gone)

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Well I cracked it open, there was a little bit of leaves, sticks, etc in there. Just a couple pieces of junk. No loose components, no leaking caps, I don't see any burnt traces on the PCB. But I am not an expert.

Ok, time to buzz out the ECU connector.

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

I can't find the link now, but I just buzzed out those pin combinations (27/40, and 46/60) on the ECU connector. There is no continuity between those pairs of pins. I'm not sure if the EVP sensor connector is supposed be disconnected or not during this test.

Also, I found this pinpoint test, but the wording is a little confusing to me.

Am I supposed to plug the ECU back in for the last bullet in the test, or leave it disconnected? Its not clear to me how the readings could be ok checking continuity of EVP to SIGRTN and EVP to battery ground. Oh, ok, wait. We are checking for a short. I will check it...

The ECU connector looks ok, but there is some yellowish grease in some of the pins - not sure if this is dielectric grease or what.

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Ok, I just ran those two tests.. Ohming out EVP to SIGRET was "0L" which means infinite resistance. EVP to the battery was 6.7 MOhms. This means I need a new processor, right?

(The processor is disconnected, as that is what the instructions say to do. I'm still not 100% on that for some reason...)

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

delco1946

Re: Hesitation just off idle (and only in gear)

In reply to this post by ckuske

I’m no mechanic but If you replaced the Egr a couple years ago, I’m concerned with the amount of metal etching that I think I’m seeing on yours, left hand side. Pulled mine off and I dont think I had that and it’s prolly 4 years old - makes me think your engine internals are under a high acid environment. Are you driving short drives, not letting your engine warm up? Maybe it’s not coming to temp either if you are driving longer enough due to radiator/ cooling issue ( valve stuck open?).

Also makes me think to check you pcv valve. They’re 3 bucks so I’d say replace it, it helped my idle and emissions (which can also lead to acidic internals). Mine was all gummed up, best 3 bucks ever spent 😆.

Christopher in Portland Or. 1981 F250 Ranger XLT 4x4 trailer special 351M, and auto C6

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Neither am I, which I why I appreciate everyone's comments and support while helping me through figuring this stuff out!

If its the picture I am thinking of, what you are referring to is a deposit of coating from the old gasket that was on the EGR, it is not etched. I should have cleaned if off before posting the picture.

You are right about not letting the engine run long enough. I am trying to run it longer these days, and I hope to fix this problem and get in on the road more often. I can drive it as-is, but I want it to be solid for my son who's just learning to drive.

I ordered a ECU, it will be here tomorrow. The plan is to plug it in and run a KOEO test first, and just see if the same codes are reported or things are "OK" then go from there. I've run the wiring tests for the EVP and everything seems to be passing, so hopefully the ECU is the problem and things run right! (No hesitation from an ECU fault in EVP circuit, and miss gone at high RPM)

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Ok, hopefully I am not speaking too soon. I had to leave home for a bit before I was able to finish things, but:

The new ECU came in today.

I installed it, and I ran a KOEO. NO CODES

I then started the truck up, and it went to high idle. No misses or stumbles at all.

I then gave it a quick punch of the gas and it stalled. BUT, I did change the accelerator pump throw in desperation move. I am going to change it back to the middle position it was in before later today, then hopefully take a test drive.

Two of the three issues are fixed just by starting/testing in the garage.

Hopefully the stumble at acceleration is fixed as well! I am guessing it will be, as the EGR/EVP is now getting processed properly by the system.

I’ll check back in later, stay tuned…

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

This post was updated on .

I have to leave again (kids are keeping me busy!) but I just ran a KOER and got 35 (EVP again!?!? - but a little different) and 45 (thermactor solenoids maybe?) as running codes.

I'll fire up Google, but any suggestions are appreciated.

My idle is low, so I’ll bump that up and see if it clears Code 35.

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

Gary Lewis

Re: Hesitation just off idle (and only in gear)

Administrator

You are making progress, and I guess it is possible that the idle speed could make a difference. That will increase the vacuum, which might do it.

PROGRESS!!!!

Gary, AKA "Gary fellow": Profile

ckuske

Re: Hesitation just off idle (and only in gear)

Administrator

Thanks, progress is something I have not had in some time!

The Internet is well.. the Internet, but looking at multiple sources a KOEO of 35 means EVP signal problems. A KOER of 35 seems to mean the idle RPM is too low to test the EGR, and this is something that I have noted as being a little low. So, I'll bump it up and see if it helps code 35.

It may mean I need to adjust the AOD rod though... (if it increases more than 50 RPM)

Then, I'll chase the code 45 (bad TAB/TAD solenoid?)

Chris

'84 F-150 XL 2WD Flareside, 302 w/ AOD transmission, Motorcraft 2150 feedback carb w/ CA Emissions, EEC-IV w/TFI, factory A/C, speed control - Info about me and my truck - My project thread

Gary Lewis

Re: Hesitation just off idle (and only in gear)

Administrator

Yep, peeling the onion, one layer at a time.

Gary, AKA "Gary fellow": Profile

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