Injector problems - ZR-1 Net Registry Forums

kengodfrey · 06-27-2014

I recently changed injectors in 1991 ZR1. Sometimes it cranks fine, runs perfect, and sometimes it sputters out black smoke, and smells like raw gas. I am assuming it is the injectors, but wanted other opinion before i pull them out and have them checked.
Thanks

Schrade · 06-27-2014

Maybe do static pressure test and leakdown time.

Doesn't seem likely tho', that it's a leak problem...................

Schrade · 06-28-2014

If your lines were fouled, your INJ's might need breakdown...

Quote:

Originally Posted by Schrade

What can ya' do to an injector with a hammer, a prybar, and a 16mm open end?
This:

Kevin · 06-27-2014

what injectors did you use? What else has been done to the car recently? who did the work? Are you sure everything is connected properly

XfireZ51 · 06-28-2014

Quote:

Originally Posted by Kevin

what injectors did you use? What else has been done to the car recently? who did the work? Are you sure everything is connected properly

Ditto.

vettn71 · 06-28-2014

If you didn't flush your fuel rails during replacement it could be a bit of dirt got in an injector. Even if you did flush them it can happen

Goof luck

Jim

Paul Workman · 06-28-2014

Sounds like a leaking injector. As suggested, a static leak test will verify it, and if so, the injector(s) at fault can be isolated.

Install a fuel pressure gauge to the Schrader valve on the front of the passenger side fuel rail.
Turn the ignition switch to RUN, without starting the motor, just long enough for fuel pressure to stabilize.
Monitor the pressure. If all is well, pressure should hold to within a couple pounds for 10-30 minutes (mine held to 30 min). (But, in your case, it sounds like a major leak, and you may even be able to observe fuel jetting from the bad injector if the ignition switch is left in RUN long enough to look down the IH bores at all 16 injectors.)

RICHARD TILL · 06-28-2014

Read your plugs.

Karl · 06-28-2014

Curious as to what type of injectors did you use?

06-27-2014	#1
kengodfrey Join Date: Jun 2007 Location: Pensacola, Florida Posts: 14	Injector problems I recently changed injectors in 1991 ZR1. Sometimes it cranks fine, runs perfect, and sometimes it sputters out black smoke, and smells like raw gas. I am assuming it is the injectors, but wanted other opinion before i pull them out and have them checked. Thanks

06-27-2014	#2
Schrade Join Date: Dec 2012 Location: NC Posts: 1,786	Re: Injector problems Maybe do static pressure test and leakdown time. Doesn't seem likely tho', that it's a leak problem................... __________________ I'm getting my snappics / threads removed blindly as fast as I can, to get in compliance with copyright / license TOS on the boards here (lots of FSM pages and other copyright / license violations on my part; sorry guys). And thanks to all the guys who didn't whine when I posted those FSM copyrighted / licensed stuff in my threads... ( :thumbsup: [b]and to think I complied with a mod's request to delete a pic of him in a Challenge Car in NCM Museum, so he wouldn't get in hot water)[/b] Thanks to several guys here for sending parts FREE; BearlyFlying, WeGone, Geezer, GoldCylon, and more there, TonyD, mike100, fletchusmc... 1990 #2794; 4L60e Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless, Power Effects 3" [IMG]https://lh5.googleusercontent.com/-GHpfzty7DVU/UQn-0Ru2xAI/AAAAAAAAA14/08mz1p4QLD4/s445/Screenshot-5.png[/IMG]

06-27-2014	#4
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: Injector problems what injectors did you use? What else has been done to the car recently? who did the work? Are you sure everything is connected properly __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

06-28-2014	#6
vettn71 Join Date: Oct 2008 Location: Colleyville, TX Posts: 272	Re: Injector problems If you didn't flush your fuel rails during replacement it could be a bit of dirt got in an injector. Even if you did flush them it can happen Goof luck Jim

06-28-2014	#7
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Injector problems Sounds like a leaking injector. As suggested, a static leak test will verify it, and if so, the injector(s) at fault can be isolated. Install a fuel pressure gauge to the Schrader valve on the front of the passenger side fuel rail. Turn the ignition switch to RUN, without starting the motor, just long enough for fuel pressure to stabilize. Monitor the pressure. If all is well, pressure should hold to within a couple pounds for 10-30 minutes (mine held to 30 min). (But, in your case, it sounds like a major leak, and you may even be able to observe fuel jetting from the bad injector if the ignition switch is left in RUN long enough to look down the IH bores at all 16 injectors.) __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

06-28-2014	#8
RICHARD TILL Join Date: Aug 2005 Location: Iuka, Mississippi 38852 Posts: 756	Re: Injector problems Read your plugs.

06-28-2014	#9
Karl Join Date: May 2013 Location: Chicago Posts: 980	Re: Injector problems Curious as to what type of injectors did you use? __________________ 1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black Sold 1985 L98 Blue On Blue Sold