I have a 1987 Chevy Silverado V10 350 TBI and I tried hooking up my AutoXray scanner and it says the RPMs is 0. When my tach says 700 RPMs. I hooked the scanner up to my 91 Firebird with 87 TPI and it says the RPMs. Could the ECM be bad since the truck runs likes like crap with the EGR hooked up, but runs better when the EGR is unhooked and backfires at 2000 RPMs by what the aftermarket tach says.

 

I figured it. I guess my brain still works. I went bought another EGR valve and opened the box. The box had instructions in it so I started reading and it said the EGR needs an orifice ring install on most. I looked at the org. EGR and that number didn't show up on the list of paper. I looked at the old one and first tried ripping off the old part, but couldn't so I found the closest size and put it in. Reinstalled the EGR valve and made sure the nuts were tight. I started the truck up and it ran pretty good. Idle at 900 RPM in Park. I revred it up and sounds great, minus the foot pedal only does half trottle.

 

man you have one weird one of a kind engine. you said a 350 v10, lol. i just thought that was funny. we all know you meant a 350 v8

 

V10 is the model for that year that got 4x4. There's also C10, R10, and so on. I have another car at home with a 350 diesel in it.