Starts up then begins to run rough and dies - ZR-1 Net Registry Forums

XfireZ51 · 02-08-2020

Went to take Z out yesterday for a quick run. It had been out a few days prior w a datalogging session. No problems. I have an Ostrich 2 emulator in the car. New bin, car wouldn’t start. Re-load, same issue. Replace Ostrich w flash prom, car starts using previous bin file but get a Code 41. Flash prom w new bin, car starts but begins to run rough then dies. No code.
I check FP, static w ignition ON jumps to 50psi then drops to 40.
Nothing changed except for loading new bin in Ostrich. With the new build, I’ve been working on refining VE table as well as setting timing now that I don’t have knock. Car has been running great. New bins flash SES w ignition ON as they should. ECM flashes Code 12 when in ALDL as it should.
Also compared the bin files and nothing appears out of whack from one cal to the other. My suspicion is fuel pump.
Discuss.

Ccmano · 02-08-2020

How long does it run before it goes rough and dies? What does the fuel pressure do it you pull the vacuum line on the regulator?
H

XfireZ51 · 02-08-2020

Quote:

Originally Posted by Ccmano

How long does it run before it goes rough and dies? What does the fuel pressure do it you pull the vacuum line on the regulator?
H

It’ll run for a few seconds then start to stumble low idle, then die.
Haven’t pulled the vacuum line.
Haven’t checked fuel pressure w motor running. Need 90* elbow to get to rail pressure fitting for that.
I hear pumps with ignition ON.

Ccmano · 02-08-2020

I would test to eliminate the fuel pumps and filter first. Go from there. Especially since no codes are shown.
H

XfireZ51 · 02-08-2020

Just checked MAP hose and regulator. Looks good.

32valvZ · 02-08-2020

Any chance the IAC is sticking at some point?

lfalzarano · 02-08-2020

Fuel pressure regulator?

Sent from my iPhone using ZR-1 Net Registry

XfireZ51 · 02-08-2020

K got it. I think the ports on my laptop are going bad. Not downloading bin files properly. Reloaded Ostrich w different cable and motor was fine. Also checked w flashprom and that worked.
Laptop not recognizing USB devices on the ports I am using.

Dynomite · 02-09-2020

Quote:

Originally Posted by lfalzarano

Fuel pressure regulator?

Sent from my iPhone using ZR-1 Net Registry

A guy near me here in CA called me about a ZR-1 that he was selling but with the same symptoms you have.....would not run.....sounded like it was flooding each time he started it. As I recall there was even raw gas in the plenum.

I worked under a floodlight after dark in his driveway for a couple hours (had to drive back and forth to my place for an operatonal FPR and some tools a couple times)

I replaced his Fuel Pressure Regulator and it fired right up and he happily drove it around the block.
He thought he would be stuck with a non-operational ZR-1 forever

I told him NO CHARGE but he gave me a NEW Set of Mag Wheels he did not install on his Truck he was soooooo excited

This was before Phil invented the "Modified Fuel Pressure Regulator" that can now be replaced without removing the plenum

I now have Phil's New Modified Fuel Pressure Regulator on ALL LT5s and even have a couple extra for a crate engine and rebuilt LT5 on the bench. It is just one of those modifications I do to ALL ZR-1s along with my standard LT5 Initial Reconditioning (Starter Solenoid, Valley Drain, New Secondary Vacuum Syatem, New Fuel Filter, New Charcoal Canister, refresh of INFL REST grounding, New 180 deg Thermostat and Aluminum Radiator ......and Blocking TB Coolant and other things including new Injectors as required and custom Haibeck Chip)

Once the LT5 is refreshed it will run forever with no Codes

Oh...almost forgot.....got to have Carter Bling on ALL ZR-1s

Post 281 - The Improved LT5 Fuel Pressure Regulator
Post 282 - Changing Out Improved Fuel Pressure Regulator (IFPR)
Post 283 - Phil's (Jagdpanzer) Fuel Pressure Regulator Solution

lfalzarano · 02-08-2020

Time for a new laptop. Make sure it has solid state drive(s). Don’t chinz out on the memory[emoji512]

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02-08-2020	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Starts up then begins to run rough and dies Went to take Z out yesterday for a quick run. It had been out a few days prior w a datalogging session. No problems. I have an Ostrich 2 emulator in the car. New bin, car wouldn’t start. Re-load, same issue. Replace Ostrich w flash prom, car starts using previous bin file but get a Code 41. Flash prom w new bin, car starts but begins to run rough then dies. No code. I check FP, static w ignition ON jumps to 50psi then drops to 40. Nothing changed except for loading new bin in Ostrich. With the new build, I’ve been working on refining VE table as well as setting timing now that I don’t have knock. Car has been running great. New bins flash SES w ignition ON as they should. ECM flashes Code 12 when in ALDL as it should. Also compared the bin files and nothing appears out of whack from one cal to the other. My suspicion is fuel pump. Discuss. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX Last edited by XfireZ51; 02-08-2020 at 11:14 AM.

02-08-2020	#2
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Starts up then begins to run rough and dies How long does it run before it goes rough and dies? What does the fuel pressure do it you pull the vacuum line on the regulator? H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-08-2020	#4
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Starts up then begins to run rough and dies I would test to eliminate the fuel pumps and filter first. Go from there. Especially since no codes are shown. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-08-2020	#5
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: Starts up then begins to run rough and dies Just checked MAP hose and regulator. Looks good. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

02-08-2020	#6
32valvZ Join Date: Nov 2007 Location: Sunshine State Posts: 1,071	Re: Starts up then begins to run rough and dies Any chance the IAC is sticking at some point? __________________ [B]1990 #2815[/B] [COLOR="Red"][B]Red/Red[/B][/COLOR] Ported Plenum & IH (by Pete) Haibeck Chip Rebuilt FPR (by Phil) FIC Injectors Watson LT Headers 3" Stainless Works exhaust Lingenfelter Open Air Lid Bill B Built Transmission Shifter & C Beam Plates [FONT=Impact][COLOR=red]1992 [COLOR=black]#[/COLOR] 091[/COLOR][/FONT] [FONT=Impact][COLOR=#ff0000]Red/[COLOR=silver]Gray[/COLOR][/COLOR][/FONT] [B]SOLD[/B]

02-08-2020	#7
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: Starts up then begins to run rough and dies Fuel pressure regulator? Sent from my iPhone using ZR-1 Net Registry __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]