92 Ford???
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92 Ford???
Okay I bought this 92 F-150 from a guy and apparently the darn egr valve wasn't even on the engine at all, 302EFI 5.0L engine we are talking about here, and I saw this egr eliminator resistor that you can buy off of fordfuelinjection.com and it will eliminate the need for a egr valve, okay so I bought it for $8 and installed it yesterday and the check engine will still come on for insufficient egr flow so I guess the resistor is telling the computer that the egr is slammed shut and will not let any flow of air go through it so that's why the computer is still throwing a check engine light on me correct, is there anyway I could get this check engine to go off for good. I am definitely not spending $80 for a new egr due to the problems they develop down the long road.....
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Joined: Sep 2004
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The computer expects to see a resistance DIFFERENCE between valve open and valve closed. A single resistor is not going to be able to show any difference. Too big, and you get a "EVP voltage above closed limit". Too small, and you get "EGR insufficient flow". The only way to possibly fool the computer is to choose a value that is halfway in between. Depending on the PCM calibration, it may accept this one value as both closed and open.
The best option is to get a custom chip that eliminates the EGR testing from the calibration. Ideally it should also adjust ignition timing considering that the EGR is not there. It would probably cost you $100 or so.
If there rest of the vacuum plumbing has not been butchered and is still in place, there is a cheaper possibility. Get a junkyard EGR valve. Wire it in place under the hood somewhere. Hook up the vaccum lines and the EVP. You need not connect it to the exhaust or the intake plenum. It doesn't actually need to induce exhaust gas -- just move in response to vacuum application. You won't get a check engine light any more. The problem with this is that you will fool the computer too well -- it may advance the timing thinking the EGR is working and you may get part throttle knocking that you don't get with the setup you have now.
Or you could take the bulb out of the check engine light.
The best option is to get a custom chip that eliminates the EGR testing from the calibration. Ideally it should also adjust ignition timing considering that the EGR is not there. It would probably cost you $100 or so.
If there rest of the vacuum plumbing has not been butchered and is still in place, there is a cheaper possibility. Get a junkyard EGR valve. Wire it in place under the hood somewhere. Hook up the vaccum lines and the EVP. You need not connect it to the exhaust or the intake plenum. It doesn't actually need to induce exhaust gas -- just move in response to vacuum application. You won't get a check engine light any more. The problem with this is that you will fool the computer too well -- it may advance the timing thinking the EGR is working and you may get part throttle knocking that you don't get with the setup you have now.
Or you could take the bulb out of the check engine light.
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Joined: Dec 2004
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fefarms, youve helped me in the past and i greatly appreciate it, but the truck still has issues... it likes to stall... if i disconect the evp connector it runs fine, (with the engine light on), but i'd like to fix it correctly. i tested the sensor as described by the haynes manual and im getting 3.665k ohms without vaccume. the book says 5K. is this acceptable?
Elder User
Joined: Sep 2004
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I'm away from home on a trip and don't have access to all of my documentation. I'm not sure what test the Haynes manual specifies -- my guess is to measure ohms from vref to EVP. Since your resistance is a little low, the EVP voltage will be a bit higher than spec with the EGR closed. The computer seems to accept this voltage if it isn't setting the check engine light and doesn't fail any KOEO tests. It might cause the computer to think that "lots" of exhaust gas is being recirculated when it only wants a little.
Your stalling problem reminds me that I had meant to retract my "fool the computer" suggestion. I think it fools the computer too well. Under part throttle conditions it would normally induce exhaust gasses into the plenum. These would have the effect of richening the mixture by about 10% (since the exhaust is inert, it cannot combine with fuel). Since we have a dummy EVP in place, the computer believes that exhaust gasses really are flowing. So it leans out the mixture by 10% to compensate for that fraction of the plenum air that has been replaced with exhaust. (Or it may lean it out by even more than that if the EVP sensor reads a voltage that is a bit too high. This could result in a stalling problem at low speeds, with a warmed up engine, above idle. Since EGR is not used at idle, you should not be stalling at idle.
I guess your options are:
1) Live with the check engine light
2) Disconnect the check engine light.
3) Hook the EGR valve up completely
Your stalling problem reminds me that I had meant to retract my "fool the computer" suggestion. I think it fools the computer too well. Under part throttle conditions it would normally induce exhaust gasses into the plenum. These would have the effect of richening the mixture by about 10% (since the exhaust is inert, it cannot combine with fuel). Since we have a dummy EVP in place, the computer believes that exhaust gasses really are flowing. So it leans out the mixture by 10% to compensate for that fraction of the plenum air that has been replaced with exhaust. (Or it may lean it out by even more than that if the EVP sensor reads a voltage that is a bit too high. This could result in a stalling problem at low speeds, with a warmed up engine, above idle. Since EGR is not used at idle, you should not be stalling at idle.
I guess your options are:
1) Live with the check engine light
2) Disconnect the check engine light.
3) Hook the EGR valve up completely
