vacuum

anlo

Registered User
well after 950.00 my sons 94 got new stock rear rotors,bled brakes, valve body from scp installed, replaced front caliper bolts and attemp at correcting a 15mph off speedo which is now about 7.. i know price a bit.. excessive... the 3 most important issues to be repaired were not resolved....= vacuum guage not reading 19-20 at idle closer to 10-11/ and firm ride light not illuminating/...slight hesitation at light throttle not at wot or idle..... any one want to take some stabs at what to look at ? only codes are related to the dpfe being most likely bad,, before you say vacuum leak i figure if vernon of all people, says theres no vacuum leak there cant be one..i had done all the correct sealing one should do before vernon got it. note to self do all repairs to your s/c yourself , youll save alot of money and learn some stuff along the way.... i knew this lesson 12 years and 5 supercoupes later but my son and his first s/c had to figure it out sooner or later so thats out of the way...... questions here are where to start diagnosing firm ride issue and can faulty dpfe or egr cause part throttle hesitating not severe but aggravating... thanks guys...
 
well after 950.00 my sons 94 got new stock rear rotors,bled brakes, valve body from scp installed, replaced front caliper bolts and attemp at correcting a 15mph off speedo which is now about 7.. i know price a bit.. excessive... the 3 most important issues to be repaired were not resolved....= vacuum guage not reading 19-20 at idle closer to 10-11/ and firm ride light not illuminating/...slight hesitation at light throttle not at wot or idle..... any one want to take some stabs at what to look at ? only codes are related to the dpfe being most likely bad,, before you say vacuum leak i figure if vernon of all people, says theres no vacuum leak there cant be one..i had done all the correct sealing one should do before vernon got it. note to self do all repairs to your s/c yourself , youll save alot of money and learn some stuff along the way.... i knew this lesson 12 years and 5 supercoupes later but my son and his first s/c had to figure it out sooner or later so thats out of the way...... questions here are where to start diagnosing firm ride issue and can faulty dpfe or egr cause part throttle hesitating not severe but aggravating... thanks guys...

An egr that is stuck open could cause this issue.
 
firm ride

i went through all 16 pages of firm ride arc related issues couldnt find anything related to this issue.. i verified switch is plugged in and verified bulb behind light is operational all acuators attached... checked fuses switched relays on arc cpu.. there is no response to switch no light when hard braking or accelerating or turning sharply or at 130 mph. no blinking lights no clicking from arc cpu.. so whats next ? my sons 94 auto. my 95 operates fine...
 
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i went through all 16 pages of firm ride arc related issues couldnt find anything related to this issue.. i verified switch is plugged in and verified bulb behind light is operational all acuators attached... checked fuses switched relays on arc cpu.. there is no response to switch no light when hard braking or accelerating or turning sharply or at 130 mph. no blinking lights no clicking from arc cpu.. so whats next ? my sons 94 auto. my 95 operates fine...

I had a similar issue with my 94 and the ARC system not functioning properly. The main ground to the ARC was broken off at the termination point. Pull the right side trunk trim away inside the trunk between the taillight and the rear wheel house. There should be a black ground wire attached to the inner quarter panel via a green screw with an 8mm head. It could be loose and that would be a quick fix. Or you may need to trace it back to the ARC computer on the other side of the trunk where the ARC computer mounts to the underside of the package tray. If that main ground is open anywhere the ARC system will not power up at all.


BTW it took me about 4 hours with a test light one day to figure all of this out. It was very frustrating.
 
Yep

^ ^ ^ what he said :) I had a similar issue on my current project, turns out I forgot to hook that ground up. I'm a dumbass. That too took a while to locate. good luck with your hunt
 
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