TPS values and throttle opening

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TPS values and throttle opening

ReneH
Hi together,

while wating for my resistors for the emissions control, I'll checked my TPS...that's what I've got:

Throttle opening by idle screw of 0,3mm (0.0118")


Closed throttle value of the TPS:


Fully opened value of the TPS:


As far as I know the TPS values are in range. About the closed throttle opening I'm not sure...I don't find a value for this...

Another question: I use an IAC from a 1990th truck...for what the hell is this black plastic cap? Something for adjustment?
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

mat in tn
i would back the throttle screw down a little more to get a little further from the 1 volt setting at least until other tuning points are corrected. only creep up on the 1v value while all else is good.
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Re: TPS values and throttle opening

85lebaront2
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Good point, since he isn't using the 1986 ECU, it shouldn't be as sensitive to not being very close to 1 volt.
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

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Re: TPS values and throttle opening

ReneH
In reply to this post by mat in tn
Ok...so if I turn the screw a bit more out, also the plates will close more.
Is there no mechanical closed throttle distance value for the base setup?
I also can change the TPS closed value by loosen the screws and turning the TPS some degrees...

And what's about the IAC plastic cap?
Before installing I have tried to carefully remove it, cause I thought there may something below...but I can only turn it...
So as I don't know what it is, I may have misaligned something...
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

Gary Lewis
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I hate to jump in here as you've been getting good advice and I don't want to slow the others down.  But you need to have the throttles closed enough that the IAC is in the middle of its range so the ECU can adjust properly.  And that takes some throttle opening, so you don't want to close the throttle too much.  Maybe try turning the TPS a bit to drop the voltage?

As for the plastic thing, I don't know what it is, but lots of IAC's have it.  And it spins but doesn't do anything.
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

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Re: TPS values and throttle opening

mat in tn
I cannot say for certain as many have this cap but not all brands. if I were to guess given its design and position it is the cover for a vented solenoid to prevent condensation from forming. no adjustments here.
also there are two basic types of iac's. one which most trucks that i have seen use which uses a spool valve through a tunnel design and the plunger design which lifts a valve on and off of a seat to adjust needed air trim. I have seen both used many times and i have seen cases where one controls better than the other. just experience and I'm still sorting out the how's and whys. maybe a good discussion. Idk.
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Re: TPS values and throttle opening

ReneH
In reply to this post by Gary Lewis
Hey Gary, I think you won't slow down the others. It's good to get different experiences together in my mind.

Ok, so there is no distance value of the plate to the throttle body given by ford?
Interesting...how have they made the setup after installing the plates...

About my IAC...one from FSB told me that the type I currently use maybe doesn't needs the diode anymore...could this be?


So when my IAC not moving, maybe cause of the diode, it also can explain why the engine only starts with unplugged vacuum hose...

Is there a way to check if the IAC works without unmounted it?
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

85lebaront2
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The diode, is wired as a "snubbing" device, it is connected so a voltage "spike" caused when power is shut off to a solenoid is dumped through the diode, but in normal usage it is an open circuit. Essentially and electronic check valve.
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

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Re: TPS values and throttle opening

ReneH
Hi Bill,

Ok, thanks.

So if nobody knows the factory opening of the throttle plate, I have to figure it out.

Regarding the IAC testing I will unmount it to check if it moves...

My resistors haven't arrived me today, so I hope I will get them tomorrow.

I will open another thread with the things left to do on my bronco...I have some urgent and also some secondary aims. So you can see, what's left. I also will post my progress there.

For the open questions or problems, i will open a thread for each them. I hope this acting will not declared as spam...
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

Gary Lewis
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Your posts won't be considered spam, so don't worry.  

On the throttle opening, I don't think there is a specified one.  But it isn't an exact science.  You need enough throttle opening so the IAC isn't running 100% duty cycle or the IAC may burn out and the ECU won't be able to control very well.

On the other hand, if you have too much throttle opening and the IAC doesn't have to run at all then the ECU will be hampered on that end as well.

So if I were you I'd get things working pretty well and then start playing with throttle opening.  I'd use my DVM to infer duty cycle on the IAC since if you see battery voltage when on the DC scale you know you have 100% duty cycle, and zero voltage means you have 0% duty cycle.  And I'd shoot for something in the 30 - 40% range.
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

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Re: TPS values and throttle opening

ReneH
OK. Good to know, Gary

So, I think it's not good to start at too many places. So I will wait for the resistors and give the EEC at first the needed values for the emission control back. As far as I understand the EGR also supplies the throttle body with air while engine is warming up. So maybe this part of air is currently missing. If the ECU thinks the EGR is open, it won't open the IAC so much...so, that's my theory...will be interesting to see tomorrow if I'm right with it.
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

Rembrant
In reply to this post by ReneH
ReneH wrote
Another question: I use an IAC from a 1990th truck...for what the hell is this black plastic cap? Something for adjustment?
Vent;).


1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995

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Re: TPS values and throttle opening

Gary Lewis
Administrator
In reply to this post by ReneH
Right, you shouldn't be changing lots of things at the same time.

But I think the ECU will keep increasing the duty cycle of the IAC until it gets the desired RPM - regardless of whether or not there is anything coming in via the EGR valve.  BUT, if you have the throttle blades closed to the point that the IAC is already running at almost 100% then the ECU cannot get the RPM up.
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

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Re: TPS values and throttle opening

ReneH
In reply to this post by Rembrant
Hey, Thanks! I also thought about a vent...but I can't imagine that this will have any use there...but maybe it has.

Thanks anyway. Now I know what it is!
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

ReneH
In reply to this post by Gary Lewis
Ok...but if I assume this, there is something wrong with my idle screw or the counterplate. The engine only starts if I turn the screw completely in or pull a vacuum hose...I can't imagine that this only results in a combination of the throttle opening and  the TPS signal...

Ignition is set to 10 deg. BTDC without SPOUT connected...and it runs very raw...maybe I need to set the timing higher cause of my 351W cam and the stroker kit...one from FSB told about 12 degrees...
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

Gary Lewis
Administrator
If I understand what you mean by "turn the screw completely in" you mean that you have to open the throttle as far as possible with the idle set screw in order to get it to run.  That seems to say that the ECU is giving the engine too much gas.  That might be due to the TPS voltage being high, causing the ECU to think the throttle is open farther than it is.

How about adjusting the TPS so that the voltage comes down?
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

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Re: TPS values and throttle opening

85lebaront2
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One item I ended up doing on my son's 1986 F150 302 was to drill two small holes in the throttle plates. The 351 throttle body may have them in there anyway. Since you probably have more access to metric drill sizes, I would start with 2.0mm and if you can't get a reasonable idle at 1.0V, then go up in small increments until you can get a decent idle. Once you get there, go one step further so the IAC is controlling your idle, otherwise it will not be able to raise the rpm on cold starts or in gear.

TPS, is not really adjustable on these, nor easy do to it's location on the bottom of the throttle body.
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

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Re: TPS values and throttle opening

ReneH
In reply to this post by Gary Lewis
Yes, you've understood what  I mean.
I also have tried to press the pedal to the floor and crank the engine to sweep out the cylinders, but there was no cutoff of the injection...the engine starts...

I have read in this book about the EEC that this should work...

But if you have seen, my TPS seems to be inside the range...
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

ReneH
In reply to this post by 85lebaront2
Hi Bill,

Ok, this sounds like a plan.

I have bought three different TPS last year and check which of them was as close as possible in the voltage range, combined with my throttle body.
It also has a little larger holes, so I'm able to adjust a bit.

So I will start with your manual and see if I can start the engine.
I also will measure if the IAC, if it gets 100% duty-cycle in warming up/idling...
René's Profile

Bronco 1986 Ford Bronco XLT 302/347 stroker with 351W EEC-IV and 351W factory cam C6 gearbox. Jeep 1986 Jeep CJ7 256 I6 with T5 gearbox. Buggy 1972 HAZ Buggy 122 Ford Cologne V6
Baron 1994 Chrysler LeBaron convertible 183 V6 4-speed automatic
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Re: TPS values and throttle opening

mat in tn
In reply to this post by 85lebaront2
I do wonder how much we are getting "wires crossed" so to speak. not certain that whether the throttle body itself is from a 5.8 or 5.0.
 by turning the base idle throttle screw all the way in you are not only allowing more air but rotating the tps also putting it well into the operating range of adding fuel. much as you would by stepping on the pedal. however, by removing a vacuum cap or hose you are not. this tells me that you may be dealing with either a map failure or you may have an injector not sealing shut when told to do so. does the system hold static pressure while turned off and for how long?
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