EGR Fooler?

[whatnot]

If there anyway to trick the ECM to not give me a code if I remove the vacuum pump?
I could probably get an F chip but my 93 also needs it done and I don't think any other chip would work in it. (it has a 4L60E transmission and mechanical pump)

[JohnC]

Maybe you need to tell us a little more about what you've got, 'cuz, well, there were no K1500 6.5 diesels in '93. There was no egr, no vacuum pump, and no computer controls on the 6.5 in '93 either...

[whatnot]

The 93 came with a 6.2L NA.
It now has a 6.5NA with Banks turbo. I took the vacuum pump off when it went bad since it I put a non-EGR intake on it.
The 93 trucks with 6.5's have computers for the transmissions with a few sensors on the engine for it.

I am just looking for a way to make the computer think it has vacuum when it doesn't.

[JohnC]

Originally posted by whatnot:
The 93 came with a 6.2L NA.
I am just looking for a way to make the computer think it has vacuum when it doesn't. The '93 6.5 did not have vacuum. Maybe the 6.2 did. Does the transmission need it? I'm thinking the '93 6.2's all were LD engines and the 6.5's all had 4L80E's. You may need to find a '92 HD computer to do HD emissions and LD trans.

But I really haven't a clue...

[whatnot]

The vacuum pump was only needed for the EGR system.
I don't think a chip for a 6.5 would work since they only came with 4L80E transmissions.

[whatnot]

Does anyone have a stock 95 "F" chip to get rid of?
I think it will fix the 95 truck and Then I will just have to figure out what to do on the 93.

[john8662]

For the 93...

If you're not currently using the EGR stuff then you don't need the vacuum pump. I think for that year your inside controlls for the A/C and heater were not vacuum controlled. The computer doesn't care about how much vacuum the pump is making because all the computer will control is when to open and close a solenoid that gives or takes vacuum to the EGR valve. This makes the valve open and close. The computer takes reading from the throttle position sensor on the side of the Injection pump to determine if there isn't a load on the engine so that the EGR can operate. The throttle position sensor also operated the transmission.

Question: does the 4L60E have a TV cable (looks like a kick down cable) this would be on the back of the engine, and have linkage to the injection pump throttle shaft?

If it does have a kick down cable, its just your basic 700R4, which doesn't need the computer, or electric controls except for lockup of the Torque Convertor. If it doesn't have a kick down cable, then it surely is entirely electronic (I doubt this in 93). I think the 4L60E became entirely "drive by wire" in 96 behind the gassers, because the diesels all had 4L80E's behind them.

So, in conclusion, ditch the pump, all it ran was the EGR. Since you already upgraded to the non egr intake, you already probably get codes for the EGR system. so you'll have to ignore those. I don't think at all that the 93 model 6.2's or 6.5's for that matter had a prom chip on the computer that was swappable. I think that was introduced in 94 with the EFI 6.5's.

For the 95...

To fool the computer on the 95 that there isn't a vacuum pump all you need to get is one of those boost foolers from kennedy. Set the boost on the boost controller and that way the computer sees boost, so assumes that the vacuum pump is operating the turbo (closing the wastegate). If your truck is a K2500 then its already F, or is this a 4x4 k2500 Light duty (6 lug wheels)? If its Light duty, I think you'll need an F chip, surely someone who has chipped their 6.5 would part with one. Mines still stock F chip, no chip in the future (just wanna get it back on the road again).

To disable EGR on a 6.5TD, there is a good post here on the forum somewhere, I can't remember who wrote it, but remember its for "offroad use only".

Good luck

[ 05-21-2004, 07:16 PM: Message edited by: john8662 ]

[whatnot]

The 95 is a 6 bolt wheel light duty.
I also put a non-EGR intake manifold on it.
The problem isn't with the boost codes, it is the EGR codes.
The 93 transmission is all electronic. (no cable)
I already removed the vacuum pump because it was bad anyway and I didn't want to buy a new one just to keep a sensor happy.
I guess if nothing else, I will have to experiment with resistors in the circuits.
It must have been a limited run with the 1993 K1500 diesels since they forgot to put it in the software for my scan tool. They have 92 and 94 1500's and also 93 2500 and 3500's but they don't work.

[Scooby]

I am not sure if the 95 ecm will be the same as the one in my 96, but I removed the egr valve and covered the holes with a blank plate (for test purposes, of course!!), but I left the electrical plug hooked to the solenoid. I dont get any codes this way. If I take the electrical connector off, I will get EGR codes.

[whatnot]

Originally posted by Scooby:
I am not sure if the 95 ecm will be the same as the one in my 96, but I removed the egr valve and covered the holes with a blank plate (for test purposes, of course!!), but I left the electrical plug hooked to the solenoid. I dont get any codes this way. If I take the electrical connector off, I will get EGR codes. But you still have the vacuum pump connected to it don't you?
I already removed the EGR valve and the hose is plugged.
The computer is doesn't mind it but I want to remove the vacuum pump too.

[whatnot]

I finally got around to playing with it and it was much simpler than I thought it would be. I just put another boost fooler on the map sensor on the firewall and adjusted it to 2.75 volts. (I will probably replace it with fixed resistors)
Now I am off to order a Turbomaster so I can remove all the vacuum stuff.

[JohnC]

Originally posted by whatnot:
...it was much simpler than I thought it would be. I just put another boost fooler on the map sensor on the firewall and adjusted it to 2.75 volts. ... I'm not sure if it's going to make any difference or not, but 2 things come to mind. first, the PCM turns the EGR on and off as it sees fit, and monitors the vacuum applied to the EGR valve through the MAP sensor on the firewall. Seems to me that there would not be any one-size-fits-all setting. Second, now your PCM has no idea what altitude it's really at, as it uses the same sensor for that as well. Of coourse, if you aren't using vacuum boost control then maybe this doesn't matter either???

Easiest way out is an "F" chip. It totally ignores the EGR circuits

[whatnot]

The hose goes directly to the map sensor from the vacuum pump.
It looks to me like it can only check the altitude on startup.

[JohnC]

Originally posted by whatnot:
The hose goes directly to the map sensor from the vacuum pump.
It looks to me like it can only check the altitude on startup. The vacuum should go to the EGR control solenoids first and then "T" to the MAP sensor and EGR valve. The PCM knows when there's vacuum applied and when there isn't. Should be smart enough to know when to check for atmospheric pressure. If you've got the EGR stuff disconnected there's no reason to have vacuum running to the map sensor.