TPS on IP for 6.5NA

[Ted Gates]

I have a nice 6.5NA engine that came setup with a fan kick down switch on the rh side of the ip. I am connecting a 4L80E on this engine and I want to connect the TPS (throttle position sensor). Problem is the shaft on IP is too long and of course does not have the end required for the TPS. Has anyone replaced this shaft? The last 6.5TD I had came with the TPS so I never worried about this in the past.

Thanks.

[dilvoy]

Yes the shaft can easily be replaced. The top cover needs to come off and then the timing advance bits need to come out while the shaft is being rotated back and forth a bit. It's pretty easy on a work bench, but on the engine the intake manifold might be in the way so you have to decide if it's easier to detach the injector lines so you can rotate the IP to get the shaft out or pull the intake manifold. Austin sells IP's that have this shaft and you can practice on the IP that has the correct shaft so you will be a Pro when you do the swap. Just be shure to get an IP that hasen't been dropped and has a bent shaft. You can also very easily turn up the fuel rate while you are doing this swap too! 1/6 of a turn clockwise of the fuel rate screw is about max. Otherwise you just put out more black smoke. That's the best compromise for smoke/power as I have found. If you live in a place where the ECO Fasciests rule the roost then only up the rate by 1/8 of a turn clockwise.

[STUDENT-DRIVER]

There is a sensor available for the NA Brad should be able to help you with a PN.
I had the same problem and made me an adapter shaft that fits in the IP's shaft:
You need to cut off the shaft of the IP a bit works good with an angle grinder without shield…

[Ted Gates]

Thanks George and Alex. I will ponder my next move on this over the long weekend.

[dunsbr]

Hi Ted,

When I was faced with the same dilemma, I found that the civvy Hummer TPS bolts straight on to the IP with the fan cut out fitted.

The Trans sensors all run on 5V generated by the TCM, so you can use civvy parts on the 24V truck with no problems.

You simply remove the plastic fan switch cam by driving out the roll pin. then reinstall the roll pin.
The shaft and roll pin then fit into the back of the civvy TPS to operate it.

The TPS weatherpack connector on the military engine harness is different to that on the civilian TPS, so you need to either make up an adapter or to fit a new connector to the TPS pigtail lead.

Cheers

[dilvoy]

Hi Ted,

When I was faced with the same dilemma, I found that the civvy Hummer TPS bolts straight on to the IP with the fan cut out fitted.

Cheers

I'm shocked at the possible fact that you may or may not have a non military item bolted to your HMMWV!

[dunsbr]

It's OK George.
That was just a temporary fix while I sorted things out.
I now have the military TPS and wiring in the truck

Cheers

[Ted Gates]

Thanks Brad for the info. I think I have one of them in the shop.

[dunsbr]

I thought you might.

Cheers

[Ted Gates]

Okay. The TPS slot insert is about to be installed. However, I will have to add spacers between the IP and the TPS for I do not want to cut the shaft. I will post pictures once it is installed. If I do not like it, I will cut shaft and redrill TPS alignment hole.

[dunsbr]

That's odd Ted....
On my truck the civvy TPS slipped straight on.
The roll pin that held the an cut off cam on fitted into the TPS slot and acted as the actuator.
No cutting required.

Can you post pics of the issue you are having?

Cheers

[Ted Gates]

I'll get pictures by the weekend. Read Alex's post, it is the same idea I am doing and I do not want to cut the shaft. Thanks.

[dunsbr]

I can understand that if you have a burning desire to run the Military TPS for authenticity (read anal like me).
But if you want a robust easy solution, why not just put the civvy TPS on?



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10137417 GM $220.00 Dealer
GRB21911 AC Delco $189.00 NAPA Bumper to Bumper
TPS146 Wells $103.99 not available
EC3003 BWD $115.17 Advance Auto Parts

Cheers

[Ted Gates]

Um, because I am civi-stupid! I will look into this and then make a decision over the weekend. Thanks Brad.

[Ted Gates]

Okay. I decided to use the military TPS and machine an adapter that will go over the IP shaft. This will reduce the space between the IP boss and the TPS. I do not want to cut this shaft because murphy law seems to find a way to screw things up, and I do not have time that. Here are pictures of the area on the IP. The first picture shows the shaft in the low idle postion and the second shows it in the wide open postion. It seems to be about 90 degree of rotation. The roll pin hole is at 95-100 degree and rotates ccw to about 5-10 degree. Hard to measure with tub on.