Code 31 Egr valve postison sensor??
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Code 31 Egr valve postison sensor??
I got a 87 ford bronco II With a 2.9 auto. I had to replace the oringal motor because of cracked heads. This motor is a 88. here's the problam some times it misses and stalls when i go to put it in gear after it sets there and runs but it really is to bad.OK The metal hose coming from the egr going to the manifold was plugged at the manifold. i had to use my lower intake and upper intake from my old motor to the new motor. So i pluged the egr at the egr were the hose from the manifold was going to. I didn't pluge the vacums at the egr. THe new motor didn't even have a egr there was a plate there to plug it off but i used my upper intake. I don't know if this is giving me code 31. I pluged the vacums it ran better and had more ***** but still code 31?? any help
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Joined: Dec 2001
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From: UT
Did you put in the '88 computer or did you keep the '87 computer? If you kept the '87 computer, you're always going to get that EGR code without any EGR system. The computer isn't smart enough to recognize that it is now controlling an '88 motor that doesn't use the EGR system.
Postmaster
Joined: Dec 2001
Posts: 3,742
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From: UT
I thought the meaning would be obvious. To put words into the computer's mouth, the code 31 means, "I'm looking for a signal from the EGR position sensor, but I'm not seeing anything. Something must be wrong. I'll assume that it's there but I just can't see it." It then substitutes a typical value for the EGR position sensor signal and operates based on that information. Of course, the reason the computer can't see any signal from the EGR system is -- it isn't there. There are a few differences in the engine control algorithm for an EGR equipped vehicle vs. a non-EGR equipped vehicle. The one I know about involves the timing advance. EGR equipped vehicles can have a slightly more agressive timing advance curve than non-EGR equipped vehicles.
It's really up to you to decide how to approach this issue. You could conceivably leave it alone. Not sure how legal this is; there are laws against interfering with emissions controls. IMO, if you wanted to do this right, you'd either adapt the '87 EGR system to fit the '88 block (if any adaptation were needed, might only need to put in the '87 exhaust manifold), or get the '88 computer and run the engine as an '88 engine.
It's really up to you to decide how to approach this issue. You could conceivably leave it alone. Not sure how legal this is; there are laws against interfering with emissions controls. IMO, if you wanted to do this right, you'd either adapt the '87 EGR system to fit the '88 block (if any adaptation were needed, might only need to put in the '87 exhaust manifold), or get the '88 computer and run the engine as an '88 engine.
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coorslight4u
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