VAM part #'s

[85xr]

hey guys, i have 2 different sized VAMS, pt#e5zf-12b529-AA, under that is these #"s 0280202071, other one is pt#e7sf-12b529-AA, under that is 0280203030. Is the e7sf the big vam?, it does measure bigger than the e5zf. the reason i ask is that the e7 is in an 85 xr. havent checked to see which comp is connected. thanks greg

[pyropete125]

the large vam in noticeably bigger- like a 1/2" or something iirc....

pete

[85xr]

yes its quite abit bigger, just trying to find out if its the BIG VAM from a turbo coupe. if it is its going into my project xr, after the rebuild. did they only put the e5 in all years of the xr? thanks

[AMXSC]

did they only put the e5 in all years of the xr?

No. Ford Part number that start with a letter indicate the decade of production e=1980s f=1990s g=2000s ect.... ect... The second digit is the year manufactured. So E5 really means 1985. The next 2 letters indicate the chassis and trim level of the car. With the next 6 digits to 8 digits the part number or assembly number. The -A or -AA is the design revision of the part. But like all auto manufactured parts do carry over from one year to the next so it is possible to get an E5 part installed on a 1989 car.

The answer to your other question.

Ford E7SF 12B529-AA 0280203030 is the correct OEM part number for a 87 or 88 Ford Thunderbird Turbocoupe Big Vam sensor.


Here is my list of compatible VAMs for reference. Hope it helps.

Large VAMs

E4ZZ 12B529-AA is from a 84 to 85.5 Mustang SVO
E4ZX 12B529-AA 85.5 and 86 Mustang SVO
E7SF 12B529-AA 0280203030 87 or 88 Ford Thunderbird Turbocoupe
E9xx 12B529-AA 84 to 86 Mustang SVO or 87 to 88 Ford Thunderbird Turbocoupe Ford Dealer Replacement parts VAM
BOSCH Part # 0280203027 BMW535i 85 to 93 BMW735i 88 to 92

Small VAMs

?unknown? 79-83 Mustang Turbo
E3SF 12B529-AA is from an 84 Mustang Turbo or 83-84 Thunderbird Turbocoupe
E4SF 12B529-AA is from a 85 or 86 Ford Thunderbird Turbocoupe
E5ZF 12B529-AA 0280202071 is from a 85 or 86 Merkur XR4ti
E7ZF 12B529-AA 0280202071 is from a 87 or 88 Merkur XR4ti
E9ZF 12B529-AA 0280202071 is from a 89 Merkur XR4ti

[85xr]

thanks for the detailed response. got my fingers crossed that i have an LA or PE comp. the car doesnt have an IC, so chances are not in my favor. to my understanding, big vam+PK comp+no IC is ok. but big vam+LA or PE+no IC=not good. the car does run though. thanks greg

[jasonty]

Weren't these carbs? My 80 Capri was.


[quote="AMXSC

Small VAMs

?unknown? 79-83 Mustang Turbo
[/quote]

[Teedyo]

thanks for the detailed response. got my fingers crossed that i have an LA or PE comp. the car doesnt have an IC, so chances are not in my favor. to my understanding, big vam+PK comp+no IC is ok. but big vam+LA or PE+no IC=not good. the car does run though. thanks greg

Just the opposite:

Big VAM + PK = Lean. More air than indicated. (less angle on the VAM = lower voltage for the same air)

Big VAM + LA/PE, no IC = Rich. Less density than presumed in tables.

[Jwheel764]

I have a 84 mustang gt turbo i recently bought an it has the big vam that this post is talking about with computer that has LA and says E7ZF-12A650-A1A. does anyone know if this computer is ok to use with the thunderbird coupe vam? The car runs and drives ok but onse the turbo kiks in the car does not accelerate very good if you drive the car normal it does ok if you try to get on it it just bogs down some times back fires some times smells like gas. Idk any information would be appreciated.

[MarkM]

The LA2/LA3 EECs are from the 87-88 Thunderbird TurboCoupes and the large VAM is the proper match for them. However, the fuel/ignition maps in the EEC were programmed with the expectation that the intercooler would also be present. If I'm remembering correctly, Mustang GT Turbos do not have factory intercoolers, so that could be affecting your drivability.

There could be other factors at work here as well. The EEC needs valid sensor inputs to run at its best. Ignition timing needs to be correct. Cam timing needs to be correct. Intake leaks and vacuum leaks can cause problems. etc.

Have you run any diagnostic codes on your car?

[andyofcolumbusmerkur]

Here was a newer thread on part numbers and casting numbers Mike collected.
http://forum.merkurclub.net/forum/viewt ... 29#p331229

[reddy2300]

thanks for the detailed response. got my fingers crossed that i have an LA or PE comp. the car doesnt have an IC, so chances are not in my favor. to my understanding, big vam+PK comp+no IC is ok. but big vam+LA or PE+no IC=not good. the car does run though. thanks greg

The Big VAM and PK computer will cause the car to be a turd. It will be sending all of the incorrect information to the computer and the computer will spit out incorrect responses. (It will run but it will not run good. I had that setup for a while back in the late 90's. Don't do it.)

If it's not an LA, LB or PE computer, save your money and wait for one to pop up. Keep in mind, LA or LB computers will need ECM wiring changed to operate in an XR. The Big VAM will plug into the OEM VAM connector.

[Ed Lijewski]

...but big vam+LA or PE+no IC=not good.

An IC isn't what's key in that combo, it's the Air Charge Temperature sensor. Intake temps are a prime table lookup for all LA series ECUs and the 8UA.

I have an 8UA-Large Vam + ACT and no IC on one XR (PE and Large Vam and TCIC on another).

So much WOTN has it that just swapping in the LA ECU and Large Vam plus IC, without installing an ACT, is all you need.

But how is the ECU to know that intake air at the manifold is cooler than air at the intake of the VAM (both small and large VAMs read outside incoming air temp) So without an ACT installed the ECU sees little difference in air temps pre- and post-turbo.

Most WOTN re using the LAs was to just move 2-3 pins and forget about installing an ACT. One XR person who knew his way around electrical shite (seriously) sold repinned LAs ready for simple swapping without an ACT with PKs/PFs. Actually, at one time he said he had pinned his LA ECU for an ACT, connected it to an ACT sensor, and just placed the ACT somewhere loose under the hood (his rationale was that that way the ECU would not fret about a missing ACT signal...).

In my case I just drilled a hole in the center of the upper intake, mounted an ACT sensor, and properky connected it to the ECU, along with the Brake Onn/Off signal by tapping into the brake light pedal harness.

How does all this work without an IC as in my case? Well, I can very easily butt feel large differences in engine power in cool/er temps that weren't as large before installing an ACT.

YMMV