Ok got a Real good Electrical problem come on in - Page 3 - ZR-1 Net Registry Forums

Corbusa · 01-11-2012

For the 1990z are there aftermarket ECM's ? or where would a person get one to keep on the shelf? Expensive.? The reason for my questions are I hope to keep my ZR for a very very long time and I need all the education I can get and slowly get parts I can afford.
At BG this year is there anyone that brings parts etc for educational purposes? Thanks Sorry I didnt mean to Hi-jack the thread..

GOLDCYLON · 01-11-2012

My money is on the quad drivers which control the injectors. In MY92 these became part of the ECM and chip circuity. We are however talking about Johnny's MY 90. Johnny swap your drivers (They are identical) then tell us which side is firing incorrectly after the swap

I sent you a PM as well. GC

Paul Workman · 01-12-2012

Quote:

Originally Posted by GOLDCYLON

My money is on the quad drivers which control the injectors. In MY92 these became part of the ECM and chip circuity. We are however talking about Johnny's MY 90. Johnny swap your drivers (They are identical) then tell us which side is firing incorrectly after the swap

I sent you a PM as well. GC

Mine is a '90, and I wuz thinking about them too (I assume we're both talking about the two quad relay modules?). But, looking at the schematic in the FSM, the primary injector current does not pass through them; only the secondaries (two quads = 8). Based on what I've read has been done - not actually being there - the ECM is floating to the top of the suspect list for me too. (Note the cautious tenor, as I (we all) have been wrong once or twice when it comes to 'lectrik chit!)

I seem to recall there are at least two schematics in the FSM touching on the ECM, DIS, and injectors... I'll keep looking, but my money is on the ECM (at the moment).

Thinking out loud, I know Marc Haibeck provides ECM service (sends them out, if I recall), so if it is the ECM, then there is a solution to that problem.

I tell ya...dealing with GM to get information on repair parts - or even just spec sheets - is a real PIA. I'm just sayin...

P.

GOLDCYLON · 01-12-2012

Quote:

Originally Posted by Paul Workman

Mine is a '90, and I wuz thinking about them too (I assume we're both talking about the two quad relay modules?). But, looking at the schematic in the FSM, the primary injector current does not pass through them; only the secondaries (two quads = 8). Based on what I've read has been done - not actually being there - the ECM is floating to the top of the suspect list for me too. (Note the cautious tenor, as I (we all) have been wrong once or twice when it comes to 'lectrik chit!)

I seem to recall there are at least two schematics in the FSM touching on the ECM, DIS, and injectors... I'll keep looking, but my money is on the ECM (at the moment).

Thinking out loud, I know Marc Haibeck provides ECM service (sends them out, if I recall), so if it is the ECM, then there is a solution to that problem.

I tell ya...dealing with GM to get information on repair parts - or even just spec sheets - is a real PIA. I'm just sayin...

P.

Yeah Paul, Johnny said he has already tried (swaping the drivers) so its on to the ECM I guess. Also the QUAD drivers only affect the secondaries and not the primary injectors. Its hard to believe only one injector out of one bank is effected by the ECM although. I know he said the harness was good but maybe there is a micro break somewhere in the harness. Anybody have an ECM to loan him. I dont? GC

I really hate electricial problems

ittlfly · 01-12-2012

Quote:

Originally Posted by phrogs

so what signals the ECM to fire the injectors?

something must tell it that it is time to fire. Is it the Camshaft sensor?

I am trying to reduce the possibilities of other things being broken other than the ECM but it looks like it is the ECM all day long..

FWIW... even with a bad cam shaft positioning sensor the engine will run and fire all 8 injectors. If it was a bad sensor it would be coding out #31. I have a new GM OEM cam positioning sensor if you are interested. A new Gm one can be hard to find. I scored a new one fron Chris over at Superior Chevy in St Louis awhile back. Cheapos are a dime a dozen....

ScottZ95ZR1 · 01-12-2012

Quote:

Originally Posted by ittlfly

I have a new GM OEM cam positioning sensor if you are interested.

I think I'd like to buy the sensor if Johnny doesn't need it, Steve.

ittlfly · 01-12-2012

Quote:

Originally Posted by ScottZ95ZR1

I think I'd like to buy the sensor if Johnny doesn't need it, Steve.

PM sent..

Pete · 01-12-2012

Quote:

Originally Posted by ittlfly

FWIW... even with a bad cam shaft positioning sensor the engine will run and fire all 8 injectors. If it was a bad sensor it would be coding out #31. I have a new GM OEM cam positioning sensor if you are interested. A new Gm one can be hard to find. I scored a new one fron Chris over at Superior Chevy in St Louis awhile back. Cheapos are a dime a dozen....

Yeap,what he said.
Try it yourself unplug the cam sensor she will start and run but will get SES light.

Pete

XfireZ51 · 01-12-2012

Quote:

Originally Posted by Pete

Yeap,what he said.
Try it yourself unplug the cam sensor she will start and run but will get SES light.

Pete

The cam sensor is used by the ECM for sequencing the injectors. Basically it tells the ECM where #1 cylinder is. After that the ECM "knows" what the firing sequence is. I like the idea of swapping harness connectors and seeing if the "new" #6 now fires.

As for the primary/secondary operation, recall that the LT-5 ECM is essentially an L-98 ECM since it was too costly to develop and certify a purpose built engine control system. The L-98 has 8 injectors. To drive the additional 8 injectors the LT-5 uses the primaries to provide the firing signal to the secondaries. The secondary relays are used to provide the power. In a way, its a bit like the operation of the LSx coils. The ECM only provides the firing signal, the power comes from the BATT.

phrogs · 01-13-2012

Yeah the Secondary Modules have been swaped sometime ago just for giggles and it didn't change anything but again they are for the secondaries. The ECM controls the Primarys.

It might be a problem finding a replacment ECM. Plus Im about to be moving again since I got my Job offer out in New Mexico. Working on CV-22s for the Air Force. Never thought I would be a Military Contractor LOL

01-11-2012	#21
Corbusa Join Date: Sep 2011 Location: TN Posts: 577	Re: Ok got a Real good Electrical problem come on in For the 1990z are there aftermarket ECM's ? or where would a person get one to keep on the shelf? Expensive.? The reason for my questions are I hope to keep my ZR for a very very long time and I need all the education I can get and slowly get parts I can afford. At BG this year is there anyone that brings parts etc for educational purposes? Thanks Sorry I didnt mean to Hi-jack the thread..

01-11-2012	#22
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,120	Re: Ok got a Real good Electrical problem come on in My money is on the quad drivers which control the injectors. In MY92 these became part of the ECM and chip circuity. We are however talking about Johnny's MY 90. Johnny swap your drivers (They are identical) then tell us which side is firing incorrectly after the swap I sent you a PM as well. GC __________________ 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 Last edited by GOLDCYLON; 01-11-2012 at 07:23 PM.

01-13-2012	#30
phrogs Join Date: Jul 2004 Location: Kalamazoo MI Posts: 1,758	Re: Ok got a Real good Electrical problem come on in Yeah the Secondary Modules have been swaped sometime ago just for giggles and it didn't change anything but again they are for the secondaries. The ECM controls the Primarys. It might be a problem finding a replacment ECM. Plus Im about to be moving again since I got my Job offer out in New Mexico. Working on CV-22s for the Air Force. Never thought I would be a Military Contractor LOL __________________ JOHNNY P Currently own 90 ZR-1 #845 DRM 500 engine package 90 #226 Parts car Hit me up if you need anything.