Help. Electrical Grimlins - ZR-1 Net Registry Forums

brandon's Z · 09-17-2014

I have what I am considering a weird one. I have recently purchased my second 1990 ZR-1 car 103.
This car was purchased at auction and I have been running the bugs out of it. It ran like SH## when I got it and now is running really well with one big issue that happen often.

Sometimes when driving the car it will have a single slight miss and then the Speedometer and AC both will quite. Then the SES light comes on and no secondary’s. The “Sys” Light also flashes indicating a code.

I ran codes the first time and got a 21,42,45,56,65. I put several miles on it while it would run great then go into the gremlin mode.

I cleared the codes (I have a OTC SPX Genies) and the car will still have this problem, but the ALDL will stops working and does not show any codes or even communicate.

When it is having this problem the scanner cannot communicate with the car at all.

Everything reads great then the gremlin appears and the scanner loses communication. I don’t have access (lost currently) my FSM. Any of the gurus around have any thoughts on why the ALDL would work intermittently like I have?

gbrtng · 09-18-2014

Classic flakey ECM problem - see if you can find a known good one to swap for a trial repair.
Someone in your area should be able to help.

GOLDCYLON · 09-18-2014

Concur... if you can swap the ECM from your other 90 see if that makes these problems go away.

batchman · 09-18-2014

Quote:

Originally Posted by brandon's Z

Sometimes when driving the car it will have a single slight miss and then the Speedometer and AC both will quite. Then the SES light comes on and no secondary’s. The “Sys” Light also flashes indicating a code.

Similar things happens to me when my battery is in a marginal state. Easier swap than the ECM if it's age/condition are not known.

Good luck,
- Jeff

brandon's Z · 09-18-2014

This is the second ZR-1 I have owned, but I don't still have the first. Anyone have a ECM that they could loan? I am in Southern Indiana

Thanks
Brandon

brandon's Z · 09-18-2014

Also is the ZR-1 the same computer as base model vette? I would assume not since we are not batch fire and 16 injectors.

GOLDCYLON · 09-18-2014

Quote:

Originally Posted by brandon's Z

Also is the ZR-1 the same computer as base model vette? I would assume not since we are not batch fire and 16 injectors.

No it is NOT the same

tccrab · 09-18-2014

Quote:

Originally Posted by GOLDCYLON

No it is NOT the same

I concur with the cycloptic moderator.
The ECM only shares the case with the ZR1, it may look the same, but the guts are entirely different.
Do not let anyone tell you different.
Been there, done that.
Save you the time and the exasperation.

'Crabs

brandon's Z · 09-19-2014

Anyone know of where I could burrow a ECM?

Thanks
Brandon

92whiteZ · 09-19-2014

Brandon,

i have a Genisys too and found it sort of interfaces with the car's systems but not completely. Have you tried someone's Tech 1 to really trouble shoot? Mine has been way more helpful that my Genisys has even been.

09-17-2014	#1
brandon's Z Join Date: Feb 2005 Location: Utica Indiana Posts: 10	Help. Electrical Grimlins I have what I am considering a weird one. I have recently purchased my second 1990 ZR-1 car 103. This car was purchased at auction and I have been running the bugs out of it. It ran like SH## when I got it and now is running really well with one big issue that happen often. Sometimes when driving the car it will have a single slight miss and then the Speedometer and AC both will quite. Then the SES light comes on and no secondary’s. The “Sys” Light also flashes indicating a code. I ran codes the first time and got a 21,42,45,56,65. I put several miles on it while it would run great then go into the gremlin mode. I cleared the codes (I have a OTC SPX Genies) and the car will still have this problem, but the ALDL will stops working and does not show any codes or even communicate. When it is having this problem the scanner cannot communicate with the car at all. Everything reads great then the gremlin appears and the scanner loses communication. I don’t have access (lost currently) my FSM. Any of the gurus around have any thoughts on why the ALDL would work intermittently like I have?

09-18-2014	#2
gbrtng Join Date: Feb 2006 Location: San Antonio area Posts: 1,179	Re: Help. Electrical Grimlins Classic flakey ECM problem - see if you can find a known good one to swap for a trial repair. Someone in your area should be able to help. __________________ “Buy the best example of what you want, and pay whatever it takes. That way, you cry only once.” ~ Bruce Meyer

09-18-2014	#3
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Help. Electrical Grimlins Concur... if you can swap the ECM from your other 90 see if that makes these problems go away. __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

09-18-2014	#5
brandon's Z Join Date: Feb 2005 Location: Utica Indiana Posts: 10	Re: Help. Electrical Grimlins This is the second ZR-1 I have owned, but I don't still have the first. Anyone have a ECM that they could loan? I am in Southern Indiana Thanks Brandon

09-18-2014	#6
brandon's Z Join Date: Feb 2005 Location: Utica Indiana Posts: 10	Re: Help. Electrical Grimlins Also is the ZR-1 the same computer as base model vette? I would assume not since we are not batch fire and 16 injectors.

09-19-2014	#9
brandon's Z Join Date: Feb 2005 Location: Utica Indiana Posts: 10	Re: Help. Electrical Grimlins Anyone know of where I could burrow a ECM? Thanks Brandon

09-19-2014	#10
92whiteZ Join Date: Sep 2013 Location: Los Angeles, CA Posts: 122	Re: Help. Electrical Grimlins Brandon, i have a Genisys too and found it sort of interfaces with the car's systems but not completely. Have you tried someone's Tech 1 to really trouble shoot? Mine has been way more helpful that my Genisys has even been.