Engine IAC adjust spacer plate factory settings

  • Sponsors (?)


manicmechanic007

5 Year Member
Sep 26, 2017
1,950
546
133
Roy, Utah
I am lost with you mentioning E cams and alphabet cams etc
I need specs to relate
Lift and duration. Overlap and centerline
I have only had three cams in mine over the 45 years I have owned it
Really liked the Crane Blazer but runs best with a close to stock cam with roughly .488 @ 290
My POS is a flowin beeach with cleveland heads on a 302 and needs not much cam
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,388
3,091
194
Kearney, NE
I am lost with you mentioning E cams and alphabet cams etc
I need specs to relate
Lift and duration. Overlap and centerline
I have only had three cams in mine over the 45 years I have owned it
Really liked the Crane Blazer but runs best with a close to stock cam with roughly .488 @ 290
My POS is a flowin beeach with cleveland heads on a 302 and needs not much cam
info on the Ford Performance cams is easy enough to find. I believe this is what you need.
 
  • Like
Reactions: 1 user

manicmechanic007

5 Year Member
Sep 26, 2017
1,950
546
133
Roy, Utah
You just install it using 2 new gaskets
Then try to make it run better (idle smoother)
By giving it more air at higher altitudes or shutting off some air if you are at or near sea level
It is trial and error for the most part
 
  • Wow
Reactions: 1 user

Willybill32

But at least it's tight!
Jul 16, 2019
425
199
53
Lexington, KY
You just install it using 2 new gaskets
Then try to make it run better (idle smoother)
By giving it more air at higher altitudes or shutting off some air if you are at or near sea level
It is trial and error for the most part
@manicmechanic007, thanks. The Mustang heads out to the body shop Monday, so it will be a while before I get the plate installed.

Bill
 
  • Like
Reactions: 1 user

vristang

15 Year Member
Mar 31, 2005
4,933
106
124
Seattle
@manicmechanic007, my ‘86 (5.0, E303 cam, TFS TW heads, shorty headers, 24lb injectors, MAF, etc.) bucks a lot below about 1,200 RPM, making it difficult to drive in parking lots, etc. My tuner says it’s all happening before the TPS says the throttle plate is open. Would one of these plates maybe help with reduce the bucking?
I realize this is a while ago, but this statement seems fishy to me...

The ecu has a RATCH feature on the TPS idle value. Basically, the ecu learns whatever the lowest TPS value is over time, and uses that as the throttle closed value (idle).
If driving around this morning yielded an idle value of 1.001v, then idle is recognized at that value, and anything above is off idle control.
If driving around this afternoon yields .998v, then TPS idle value has changed.
Disconnecting battery will allow it to reset. I'm sure there is a hysterisis, but don't recall the details on it...

Basically, anything higher than the RATCH, is recognized as 'off idle'. By 1,200rpm, you should be well off idle?

I don't have experience directly with the E303, but the cam I had in my 408w bucked really hard until about 1500-2000, IIRC.
That is until I corrected the injector timing, based on the cam specs. After that, it pulled strong at idle, which was then lower, maybe 800?

I suspect that cam, low speed bucking issues, are more to do with injector timing than most give credit for... But just my own personal theory...
 
  • Like
Reactions: 1 user

manicmechanic007

5 Year Member
Sep 26, 2017
1,950
546
133
Roy, Utah
I am not sure what you mean by cure the bucking with the E303
The plate was designed to cure surging idle on a Tempo (or 4 cylinder 2.5 Taurus)
It is basically used to add air to the engine without the processor knowing about it
A / the hot Idle Compensator (in the air box) does the same thing
We used to just bend the spring on those so they sucked air in all the time, instead of just when hot
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
24,045
8,893
203
polk county florida
Here is my experience and opinion,
my E cam bucked at low rpms also, you could drive around below 1500 rpms in any gear without it trying to tear up the trans, drive shaft and rear gear. Only way to correct this, if you wanted low rpm drivability, was a chip or aftermarket ecu (to my knowledge), the computer just could not keep up with the cam change. New cams are 'duel pattern' for this reason. (This is a layman's understanding).
The IAC plate was install per a TSB for drivability issues on a stock car or truck. This plate will likely have little to no effect on an engine with a E cam.
As I understand it, the TPS values (voltage reading) is given to the computer on each startup and that 'start up' reading is set until the engine is shut down (key off). It is not 'stored' by the computer and reused at new 'start up'.
This, again, is my understanding.
I recently worked on a F150 with this plate on a 351 efi and found it did nothing, changed nothing no matter where the set screws were or if the plate was installed or not, this was verified before and after the computer was rebuilt by ECUexchange.
 

manicmechanic007

5 Year Member
Sep 26, 2017
1,950
546
133
Roy, Utah
True story
I believe Ford installed a few on the Lightning trucks
We used to see them on all kinds of vehicles a few years after they came out
Some dealer techs somewhere must have been putting them on
We used to take them off if we had any codes for lean or rich
Fixed a few cars by taking them off
Had to put a few back on
Before 1996 we were fighting tailpipe emissions and not just the light
 

vristang

15 Year Member
Mar 31, 2005
4,933
106
124
Seattle
Maybe my memory is hazy, and ratchet does reset each startup, it’s a 15yr old memory at this point, lol.

I guess the point I was kind of dancing around, was that I don’t think these plates will do much of anything for low speed bucking issues, especially when a cam has been installed, as injector timing is a bigger factor with cams than most realize, especially at low speeds.
 
  • Agree
  • Surprised
Reactions: 1 users

Willybill32

But at least it's tight!
Jul 16, 2019
425
199
53
Lexington, KY
Maybe my memory is hazy, and ratchet does reset each startup, it’s a 15yr old memory at this point, lol.

I guess the point I was kind of dancing around, was that I don’t think these plates will do much of anything for low speed bucking issues, especially when a cam has been installed, as injector timing is a bigger factor with cams than most realize, especially at low speeds.
@vristang, thanks for the input. At this point I’m just grasping at straws, trying to hopefully find a solution. Knowing what I know now, I would have used a different cam. It appears some people have no issues with the E303 and others do. Would the tuner be able to adjust the injector timing?
 

vristang

15 Year Member
Mar 31, 2005
4,933
106
124
Seattle
Yep, a tuner should know exactly what to do, if he doesn’t…. Might consider finding another tuner, lol.

It was easy to do with a moates quartehorse and binary editor, if you are into diy…