dat240zg Posted October 31, 2009 Share Posted October 31, 2009 Just got the Z back from a local rod shop that was suppposed to setup the NOS system for me and investigate an ignition switch issue (whether the ACC portion of the switch was wired correctly). After some time, almost 2 months, the owner of the shop stated that he was having a hard time getting the Z to start after doing some work on the ignition switch wiring. I put him in touch with John @ Speartech who said that the problem sounded like a major vacuum leak (car would crank for a long while before firing, then would be pig rich and miss on several cylinders). BTW, it ran well going in to the shop. I got a call from the owner that the issue had "cleared up" and the Z was ready to get picked up. I went this past Tuesday to pick it up and although it took forever to get started, the car seemed to run smoothly. About 5 miles in to the trip home, the Z began missing extremely bad and loosing power, all intermitently. The car died several times on the way home and would seem to be running on 3 or 4 cylinders. The farther I went, the worse it got, to the point that I was really focussed on just getting home. Long story short, I pulled the plugs as I can't even get the car to start now. The plugs for the front 4 cylinders look good, but the back four look flooded. I've checked the obvious (vacuum leaks, etc) and can't see any thing out of the ordinary. Anyone have any thoughts (other than take the car back)? Fuel pump is running and is developing good pressure, but the car just isn't firing. Thanks in advance - I'm down to my last two hairs with this thing... Bryan Quote Link to comment Share on other sites More sharing options...
deja Posted October 31, 2009 Share Posted October 31, 2009 Are you getting any error codes? Have you tested the dreaded opti yet? http://shbox.com/1/4th_gen_tech2.html#opti_test Sounds like maybe you're geting no spark to the back cylinders. Might also be the ICM (ignition control module) Quote Link to comment Share on other sites More sharing options...
gvincent Posted November 2, 2009 Share Posted November 2, 2009 Having just gone through something similar, I swapped out the suspected fuel injectors and everything was happy again. The click test didn't locate the bad clogged injectors, even with 2 filters you can suck up some nasty stuff from our old tanks. Of course I went through all the electrical first, and all checked out. Even bought the NOID lights to check the injector pulses. Check for the voltages at the coil/ignition module for 10VDC being present and 5VAC while cranking, I forget which pins right now but can look it up for you, it is in the manual Originally tried to blame the poor old OPTI but had a hot spark at each plug with a spark tester and also tested each plug wire and spark plug with a clamp on timing light Of Course check your fuel pressure at the fuel rail and Fuel Pressure regulator. Too low pressure from a partially clogged inline filter or intermitant fuel pump can do the same thing, been there done that. Good luck, Greg Quote Link to comment Share on other sites More sharing options...
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