VMP Twin 67mm Throttle Body Issues

[AmkoA]

Current mods: PMAS CAI, 1 7/8in LTH, Corsa Xtreme catback, catless, ported gen 2 cobra jet intake manifold, and stage 1 Comp cams. E85 tune by Lund.

Anyone having problems with the VMP twin 67mm throttle bodies? When I first installed it, my car went into limp mode immediately with idle surge, high idle RPM, and P0120 (throttle position sensor A circuit) , P0124 (throttle position sensor A intermittent), and U2110 (throttle position sensor/switch A communication circuit high. They sent me a 2nd one and essentially the same things occur but now only when the car is warmed up after about 10 minutes of idle. I did notice on time I let the car idle for 15 minutes or so and as soon as I turned on the AC the issue occurred. I am speaking with them now on replacement or refund. At this point, I don't even know if I want to try a 3rd unless they test the throttle body beforehand and confirm it works. Thinking of going with Ford Performance Twin 65mm with JMS Controller. Logged the vehicle with FORScan and HP Tuners. Desired throttle angle stays at 0 while actual angle is around 7 degrees with actual idle RPM 1500-2500 versus desired at 800. Lund says the throttle blades may be getting stuck when hot or there may be a tolerance issue. I tested the following:

* Verified 5.06 V reference at the throttle body.
* Verified sensor ground circuit.
*Cleaned MAF sensor and verified no electrical noise from alternator
* Verified throttle motor operation during KOEO initialization.
* Inspected connector, terminals, and wiring for damage or loose pins.
* Performed a harness wiggle test with no change in operation.
* Tested with the supplied VMP extension harness installed.
* Confirmed the same concern exists on two different Lund Racing tune revisions.
* Unplugged the first VMP throttle body and plugged in my original OEM Ford throttle body electrically. With the OEM throttle body connected electrically, the wrench light was no longer present during KOEO, and the throttle status changed from TP_F = Fault to TP_F = No Fault. The only component changed during this comparison was the connected throttle body. With the 2nd throttle body, it only goes into fault once car is warmed up and starts idle surging/high idle/etc.
* Repositioned the heater/coolant hose away from throttle body and heat shielded the throttle body and hose and harness. Repositioned the coolant resovoir as well.

Any ideas? Should I try a 3rd one and take my chances again with down time on my car or just get a refund and go with the Ford Performance Twin 65mm?

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[K Myers]

Had same problem when I switched to a gt 350 one, get you battery load tested.

 

[AmkoA]

Had same problem when I switched to a gt 350 one, get you battery load tested.

Is that something autozone can do? Do you think the AC could be involved too?

 

[robvas]

When I had a similar issue I traced the wiring from the ECU to the throttle body connectors and found two wires that were not connected securely.

Are you using the 'new' style throttle body they came out with last year or so?

 

[AmkoA]

When I had a similar issue I traced the wiring from the ECU to the throttle body connectors and found two wires that were not connected securely.

Are you using the 'new' style throttle body they came out with last year or so?

Yes the new one with the updated gasket. I verified voltage to the power wires and ground wire. I didn’t check continuity for all 5 wires from the ECM connector to the throttle body. Where were these 2 wires not connected securely?

 

[robvas]

Yes the new one with the updated gasket. I verified voltage to the power wires and ground wire. I didn’t check continuity for all 5 wires from the ECM connector to the throttle body. Where were these 2 wires not connected securely?

I have a gen 1, there's a weatherpack connector on the passenger side valve cover that joins two sections of the wiring harness

 

[AmkoA]

Is that something autozone can do? Do you think the AC could be involved too?

I had Autozone check it and they said 72% charge/CCA which I guess it’s low so I’ll go ahead and replace it. It’s cheap anyway and a couple years old and then see how it goes.

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