i found an non egr intake for low money. i dont have emissions and i want to get it. wont the computer mess up if i take the egr out?? can i trick it to think its still there. cause wont it go into "limp mode"ive been there and it suxed. please tell me soon cause i really want to give my car a little more horsies.

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86 IROC LG4,DUAL SNORKEL,AMERICAN THUNDER,3.27 GEARS

 

IROC,

The easy way is to get a custom PROM. You can partially "fool" the ECM by connecting a resistor in the circuit in place of the EGR solenoid, but the other check the ECM will perform is to expect an increase in MAP signal when the EGR is supposed to be open. I'm not sure how you could do that without an elaborate circuit to add some MAP voltage when the EGR solenoid output is on. A quad OP AMP with a fixed value at one input combined with a scaled value from the existing MAP sensor, routed through a third section for the ECM input could be tricky.

Another option would be to install a Corvette-type EGR separate from the intake, but a carb spacer designed for the purpose could be tough to find.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

 

I've been down that road before with no EGR. The problem comes from the ECM spark advance curve. It is very fast and steep to compensate for the EGR. Disconnect the EGR, or do anything to keep EGR from taking place, and the engine will ping. The pinging will be severe at times.

As Vader said, you will need a custom PROM. One that doesn't have an advance curve that assumes EGR and the back pressure of a stock exhaust. Again, as mentioned before, you'll need to make the ECM believe that all is well.

I s'pose it would be easier to just set up your "non-smogger" as a pre-1973 Chevy 350. Go get yourself a regular Q-Jet, a regular vacuum-adv. HEI distributor, and take it from there. Chevy 350's made before 1973 ran pretty good as I remember and anybody with a room-temperature IQ could work on one!

 

WOULD MY Q JET THAT IS ON THERE WORK OR NOT. PROBALY NOT. I GOT AN OLD Q JET AND VAC ADVANCE FROM A early silverado. that would probaly work right>?

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86 IROC LG4,DUAL SNORKEL,AMERICAN THUNDER,3.27 GEARS

 

Oh, that electronic Q-Jet would "run" alright--like crap! That ECM Q-Jet, and ECM-controlled distributor, is part of an integrated system. They are NOT stand alone items.

Cars have had all of this computer stuff on them for about 20 years now. It amazes some to look at a Stone Age SBC, with only a plain carb and plain distributor, and see it run! "You mean engines will run without all that computer stuff"? That old Q-Jet ought to bolt to your non-EGR manifold without any problem. Unless that Silverado was a 3/4 ton truck, the Q-Jet will probably be a bit lean. I would think that a pre-1980 HEI distributor ought to drop right in without a problem. If your Siverado had EGR, the distributor advance curve is probably too fast for your engine. Play it safe and start off with a lame advance curve and then get more aggressive from there.