03-24-2015 | #1 |
Join Date: Feb 2010
Location: Ochlocknee, GA
Posts: 435
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miss after car warms up
Hi,
I have a miss condition when driving the ZR-1 after about 25 miles, then the miss starts. The engine temp is between 185 deg. to 191 deg. The miss is a gurgling sound at low speed or when more throttle is applied. The tech 1a shows no codes , all readings look ok per FSM for 1990 car. I have rpl the coils , rpl fuel filter ( some water in filter) drained the tank about 5.5 gals. refill with fresh gas and seafoam for 10 gals. Drove car but same trouble after car reaches operational temp. Waiting for compression gauge to do that test. Org. wires rpl at about 66000 miles. car has 127400 miles. What else can or should i do to resolve this condition? THANKS John Becker 1990 white/black #2546 one of a few auto (4l80E) eq. ZR-1's |
03-24-2015 | #2 |
Join Date: Jun 2009
Location: I live at Devens, one run at a time
Posts: 455
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Re: miss after car warms up
Have you changed injectors yet? I just have a feeling...
Best, - Jeff
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[I]91 ZR-1 #1840, autocrossing in SCCA BSP. FIC S/S's DRM chip/Watson/Borla/lid/LW batt&headlights, springs, shocks, pads & lines, quick rack & Turn One, camber brace, 32/22mm sways, A/C halfway deleted 17x11 & 12 CCW's, 315 & 335 Hoosier A6s [/I] |
03-24-2015 | #3 | |
Join Date: May 2013
Location: Beaver, PA
Posts: 516
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Re: miss after car warms up
Quote:
Measure the resistance of the injectors when hot. I had 4 bad ones but only when hot. When cold they measured ok. They were the original injectors and failed at 55K miles. If yours have been changed its still a possibility one could be bad electrically or mechanically. Good luck. |
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03-24-2015 | #4 |
Join Date: Feb 2010
Location: Ochlocknee, GA
Posts: 435
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Re: miss after car warms up
Injectors rpl in May 2012 with FIC @ 117141 miles. I have not checked
the readings of the injectors , will try that after comp check. Also i'll check inj leak test before resistance check. Warm motor to 179 deg. then wait 10 min ,due comp check. then leak test and then resistance check. Thanks John Becker |
03-24-2015 | #5 |
Join Date: May 2013
Location: Chicago
Posts: 980
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Re: miss after car warms up
Check the oxygen sensors. I replaced mine and the difference was night and day. The sensors looked original and will not necessarily throw a code if bad.
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1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black *Sold* 1985 L98 Blue On Blue *Sold* Last edited by Karl; 03-24-2015 at 06:45 PM. |
03-25-2015 | #6 |
Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
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Re: miss after car warms up
Dittos on the injectors, AND what Karl said as well. Both of these items (at different times) caused a miss for me w/o throwing any codes.
One more item might be to ohm out the coils; another one of those items that often show up only after they are up to operating temperature.
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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 |
04-05-2015 | #7 |
Join Date: Feb 2010
Location: Ochlocknee, GA
Posts: 435
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Re: miss after car warms up
Update:
Have been working for the last 3 days so no time to work on car. Order new gaskets from Jerry (used my last spare set). also picked up new plug wires . Well plug wires came in Wed. morning and after installing them mail shows up with my gaskets (thanks Jerry). While car was apart i did the TB bypass. After putting it all back together made my test run 55 miles local and highway , no more miss at low or high speed. So what i replaced is Coils ( first set was bad they took them back and got the best set of coils). o2 sensors they were black from miss fire. Plug wires ( this i'am sure was the main root of my miss ). injectors check out ok did not do comp check Thanks to all who help steer me in the right direction. John 1990 white/black #2546 one of a few (4l80E ) eq. Zr-1's |
04-05-2015 | #8 |
Join Date: Feb 2010
Location: Pendleton, IN
Posts: 3,904
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Re: miss after car warms up
Happy to hear of your success!!!
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1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project |
04-06-2015 | #9 |
Join Date: Aug 2014
Location: Kansas City, MO
Posts: 838
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Re: miss after car warms up
I have been having a slight bucking under 2,000 RPM occasionally. It seems after the car is warmed up. I just replaced all my coil packs a week or so ago. It still bucks a bit.
I replaced my injectors with Accell injectors, spark plug wires with Denso OEM ones, and single platinum autolite plugs. I'm starting to think my ECU has some issues. My service ride control is on, and occasionally my Service ABS light comes on.
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Looking for a ZR-1 1985 Yamaha RZ350-NOT STOCK 1971 Yamaha AT1-Middle of a restoration |
04-06-2015 | #10 |
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,251
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Re: miss after car warms up
Could it be the Autolites?
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