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TPS

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Gary Lewis

Re: TPS

Administrator

I'll let Bill work with you on that.

Bill - I have the documents here: Fuel Systems/Diagnostics.

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

mp470

Re: TPS

I know it's a lot to process, sorry to be a nuisance.

Anyways, I got back out there just to start from scratch. Didn't even turn the key this time, purely for sensor resistance checks and to write everything down this time. ECT was 124k ohms and ACT was 126. It's about -5C outside. Too far out of range, or perhaps they need to be warmed up before testing?

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

Gary Lewis

Re: TPS

Administrator

You still need Bill, but at -5C it looks like the ECT should have been about 70k ohms instead of 124k. That's way out of range, but I don't think it would cause a huge problem since all that tells the computer is that it is REALLY cold out - like about -50 C. But the engine should still start and run. The real question is what the ECT resistance is when the coolant is up around 80 degrees C or 180 F.

But I don't see an ACT scale, so I don't know what to say about that. Perhaps Bill can enlighten us.

Gary, AKA "Gary fellow": Profile

mp470

Re: TPS

ACT and ECT should be identical sensors in every way if I'm not mistaken.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

Gary Lewis

Re: TPS

Administrator

That being the case, they both look to be way off. But it is hard to believe they can both be that far off and yet so close together. Can you pull one of them and take it inside to check it at a much warmer temp?

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: TPS

Administrator

I would try the ACT as it won't leak water if it is removed, yes they apparently are the same since the value charts are the same.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

mp470

Re: TPS

Out came the ACT. It's carboned up pretty bad but appears to be original. Part E4AF-12A697-AA embossed on the connector. Even with the carbon, readings appear to be right on the money with warm temperatures from 20-100C and smooth transitions in between. It's soaking in some throttle cleaner for a bit, then may put it in the freezer to measure cold. The ECT will be much easier to remove, hopefully doesn't lose much coolant - i don't think it will.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

Gary Lewis

Re: TPS

Administrator

That is the right number for the air charge temp sensor. Used on a whole lot of trucks.

Gary, AKA "Gary fellow": Profile

mp470

Re: TPS

Well, I believe my issue is resolved (at least this one). The idle screw was out way too far, I feel like an idiot. I'm still a bit confused as to why it would start fine cold but not hot though. In any case, it's fixed. Thank you all for the help.

I was able to finally do a proper KOER test and the codes are 41 and 34. I tested the EVP and it gets 5V and the resistance is around 4000 ohms at rest and 500 with the sensor solenoid(?) fully pressed in (I removed the EVP from the valve for this test). It fluctuates smoothly. Haynes manual says 5000 at rest and 100 with 20inHg of vacuum. Waiting for pump in the mail. The only strange thing is that there is no vacuum going into (or coming from) the green line attached to the EGR valve. The line itself is intact all the way to the assembly that controls the vacuum at which there is none either. Need some guidance on this possibly.

The O2 sensor, I will have to locate later so I can do testing on it. I take it the access is from underneath.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

Gary Lewis

Re: TPS

Administrator

Peeling the onion! One layer down - how many to go?

The codes you are getting are as follows, from this page, with O = Key on Engine Off (KOEO), R = Key on Engine Running (KOER), and C = Continous Memory:

41 R Injectors out of balance on 5.0L SEFI; EGO sensor voltage low (except 5.0L SEFI)

34 O,R,C Canister or EGR valve control circuit or EVP voltage high

So, you will have to check out the O2 (EGO) sensor. And coming from underneath is the way to do that.

Gary, AKA "Gary fellow": Profile

mp470

Re: TPS

Thanks Gary.

I have seen quite a few descriptions for code 41 but none of them had anything to do with injectors, mostly the O2 sensor / system too lean. Now it is EFI, but whether SEFI or something else I'm not certain. It could lead one astray if unsure of which one.

For the code 34, the EVP circuit is OK. I've read up on this site as well as a few others but there isn't really a theory of operation anywhere that I could find. Perhaps the lack of vacuum at the line is normal during idling, I'm not sure.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

Gary Lewis

Re: TPS

Administrator

I don't think yours is SEFI, which stands for Sequential Electronic Fuel Injection. If you look at Page 61 in the 1986 EVTM you'll see that injectors 1, 4, 5, & 8 fire together, and 2, 3, 6, & 7 fire together. That is "bank fire" not sequential, which didn't come until later.

On the code 34, I don't have a theory of operation on the EEC's. I haven't really seen one that I could put up. And I don't know about the vacuum at idle. Sorry.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: TPS

Administrator

No EGR vacuum at idle, not if you want it to idle. Red line from intake is vacuum source to control valve, it should have vacuum with the engine running.

Bill AKA "LOBO" Profile

mp470

Re: TPS

It does. I'll assume that part of the equation is OK. Will wait for the vacuum pump to see if the valve operates correctly.

That O2 sensor is damn near impossible to get to from below or above, might just leave that one be, especially if the testing needs to be done hot.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

vjsimone

Re: TPS

This post was updated on .

There is a connector just up from the O2 sensor on the passenger side just above the exhaust manifold. If you disconnect it carefully, and attach your meter, you should be able to measure the output of the sensor. The range is about 0.0 - 1.0 volts dc, lean to rich.

When it is working properly, and warmed up, it will switch between about 0.4 - 0.7., providing the ECA/Computer is adjusting the Fuel Injector pulse width, and there are no vacuum leaks, spark failures, fuel pressure or Air Bypass issues.

Vinny... "Do All Scheduled Maintenance Prior To Troubleshooting" "Resolve All Known Issues Prior To Troubleshooting"

vjsimone

Re: TPS

In reply to this post by mp470

Does your EVP look new ?

Unscrew the EVP, lift it up/out, leave the electrical connector attached, run your KOER to see if the Code 34 goes away. Unless you are creative, you will get other Codes for this test.

Vinny... "Do All Scheduled Maintenance Prior To Troubleshooting" "Resolve All Known Issues Prior To Troubleshooting"

85lebaront2

Re: TPS

Administrator

A friend and I used to file the plungers on the EVP sensors when you could not get the code to go away. Worked great on a lot of them.

Bill AKA "LOBO" Profile

vjsimone

Re: TPS

Yes, that's where I am going with this...

Vinny... "Do All Scheduled Maintenance Prior To Troubleshooting" "Resolve All Known Issues Prior To Troubleshooting"

mp470

Re: TPS

In reply to this post by vjsimone

Not new for sure but it gets voltage and the resistances are close to spec as per Haynes, including when the plunger is adjusted in and out, could even be original. I will try this trick.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

mp470

Re: TPS

In reply to this post by vjsimone

What does filing the plunger down do? I've yet to find out if the valve is actually operational, waiting for vacuum pump to see if it will at least hold vacuum. Does the KOER test actually attempt to operate the valve? I think I read this somewhere.

1985 F-150 XLT Lariat, 5.0 EFI, RWD, 8.8 Axle

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