'91 missing and would like a second opinnion - Page 6 - ZR-1 Net Registry Forums

ZR-1Mikko · 02-01-2010

I was hoping I could have figured this one out, but after a bunch of diagnostics I'm not really sure where to look next. So I would appreciate your guys second opinion.

At this point I have already measured, coils, wires and injectors and they are all perfect and also less than 1 year old. Also installed new plugs and they all look fine after my test runs. Also I do not get a check engine light.
Car starts fine and runs perfect on idle. As soon as it warms up even a little bit the idle becomes rough and I start to hear occasional knock. when I take off it runs like a 70's vette at start and sometimes starts running smooth when I hit about 2000rpm. When I get it running normally under a steady throttle it runs fine, but starts stuttering when I step on it.

So I'm wondering if O2 sensors could cause this and not give a check engine light or could it be the fuel pump?

02-01-2010	#1
ZR-1Mikko Join Date: Dec 2005 Location: Las Vegas Posts: 108	'91 missing and would like a second opinnion I was hoping I could have figured this one out, but after a bunch of diagnostics I'm not really sure where to look next. So I would appreciate your guys second opinion. At this point I have already measured, coils, wires and injectors and they are all perfect and also less than 1 year old. Also installed new plugs and they all look fine after my test runs. Also I do not get a check engine light. Car starts fine and runs perfect on idle. As soon as it warms up even a little bit the idle becomes rough and I start to hear occasional knock. when I take off it runs like a 70's vette at start and sometimes starts running smooth when I hit about 2000rpm. When I get it running normally under a steady throttle it runs fine, but starts stuttering when I step on it. So I'm wondering if O2 sensors could cause this and not give a check engine light or could it be the fuel pump? __________________ If you don't put the miles on it, someone else will...