Ok guys new member here I bought a 90 coupe last summer for $500 did a few mods the car ran great before the mods drove the car for a few months before winter right before I put it away it started acting up it runs good before going into closed loop then it back fires badly and popping and missing also vary badly to where it’s not even drivable I pulled the codes and came up empty handed with only smog code but all has been deleted long before the issues arose ..but I had a pile of parts waiting for the car so I put them on anyway maybe a bad decision but the isssue is still present
Mod list (issue started before these mods)
System max intake
Gt40 heads valves springs 1.7 rockers
75mm tb
24lb injectors with maf (had 19s with stock maf same issue)
B21 cam (push rod length is correct) also checked lifter preload
Adjustable fpr (40 psi with vacuum off)
Headers h pipe cat back
5 speed swap
A9p computer
Cai
I had a lot of good parts laying around fresh off my other car I’ve swapped distributors,ect,act,tps,map/bap,3 tfi modules,2 mafs new coil tried others new plugs new plug wires,fresh gas timing is set to stock ive set it twice to rule it out also have checked firing order and plug wire orientation but the car ran great up until the day it did not only thing I haven’t touched is the o2s but I’m getting no codes for them ive also checked the salt/pepper shakers,maf plug,coil plug,and tfi plug for corrosion all is good I’ve also upgraded the alternator but the problem was present with old one as well
Mod list (issue started before these mods)
System max intake
Gt40 heads valves springs 1.7 rockers
75mm tb
24lb injectors with maf (had 19s with stock maf same issue)
B21 cam (push rod length is correct) also checked lifter preload
Adjustable fpr (40 psi with vacuum off)
Headers h pipe cat back
5 speed swap
A9p computer
Cai
I had a lot of good parts laying around fresh off my other car I’ve swapped distributors,ect,act,tps,map/bap,3 tfi modules,2 mafs new coil tried others new plugs new plug wires,fresh gas timing is set to stock ive set it twice to rule it out also have checked firing order and plug wire orientation but the car ran great up until the day it did not only thing I haven’t touched is the o2s but I’m getting no codes for them ive also checked the salt/pepper shakers,maf plug,coil plug,and tfi plug for corrosion all is good I’ve also upgraded the alternator but the problem was present with old one as well
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