Big D
06-13-2015, 05:35 PM
Hi all, my 90 ZR1 is missing/rough running at all speeds especially when it reaches operating temp. Turning the poser key on and off made no difference. I get spark at all plugs but when I pulled the #3 wire the idle didn't change much. Let her cool down and pulled the plug and the plug showed little evidence of firing. Didn't smell much of fuel either. Pulled a couple of others and they looked good. Next step was to check injector resistance and it was as follows: 1:15.3, 2;14.5, 3:5.7, 4:14.7, 5:13.0. 6:17.8, 7:15.1 and 8:17.3. I replaced the #3 plug and still the same. this time I checked the injector resistance when it was still hot and got the following:1:18.2, 2;19.8, 3:8.0, 4:19.8, 5:11.0. 6:20.6, 7:18.8 and 8:20.4. Now I'm thinking maybe a bad injector at #3 and maybe #5. If so, looks like I'll be pulling the plenum for the first time, what fun. Any suggestions would be appreciated
Big D
'90 ZR1
'69 L46/M21
Big D
'90 ZR1
'69 L46/M21