ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 General Postings

Reply
 
Thread Tools Display Modes
Old 07-21-2014   #1
Schrade
 
Join Date: Dec 2012
Location: NC
Posts: 1,783
Default Why don't they start right up?

Does any one know with certainty why LT5 doesn't start right up immediately?

Was it the same way on the showroom floor?



This is the first electronically FI car I've owned that didn't do so instantly. Even the first one I owned, an L-98 that was in a poor state of tune when I got it, would start immediately. Foreign, domestic, 4's, 6's, etc.

On RARE occasions, it WILL fire almost instantly. But most of the time, it's 2 - 3 seconds. And I'll let off the starter then, and re-try.

I thought I read once on the boards here that ECM had to see some crankshaft position first, before issuing fire @ the plugs; this would mean, if correct, that it WOULD have exhibited the same behavior at the dealer, when new.

Does anyone know DEFINITIVELY the answer here?

Schrade is offline   Reply With Quote
Old 07-21-2014   #2
Kevin
 
Kevin's Avatar
 
Join Date: Jun 2005
Location: pittsburgh
Posts: 4,624
Default Re: Why don't they start right up?

Quote:
I thought I read once on the boards here that ECM had to see some crankshaft position first, before issuing fire @ the plugs; this would mean, if correct, that it WOULD have exhibited the same behavior at the dealer, when new.
this is what I've always heard to be the case also.
__________________
It's not the car, it's the people - Doug Johnson
90 r/r "KEYS ON" nick named "T.L.B"
Kevin is offline   Reply With Quote
Old 07-21-2014   #3
BigJohn
 
BigJohn's Avatar
 
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,301
Default Re: Why don't they start right up?

Never noticed!
Mine starts right up with a good battery.
BigJohn is offline   Reply With Quote
Old 07-21-2014   #4
QB93Z
 
QB93Z's Avatar
 
Join Date: May 2007
Location: Westminster, Maryland
Posts: 3,684
Default Re: Why don't they start right up?

It could be because the Crankshaft has to rotate until the Ignition Module gets a signal from the Crankshaft Position Sensor so it can determine the correct ignition timing.

Jim
QB93Z is offline   Reply With Quote
Old 07-21-2014   #5
RyanChappel
 
Join Date: Aug 2012
Location: Boone County, Indiana
Posts: 132
Smile My lo-mile '91

with new Accel injectors and a good (batt-tender maintained)charge, has to crank a couple seconds to fire...and I'm always thrilled it did...
RyanChappel is offline   Reply With Quote
Old 07-21-2014   #6
We Gone
 
Join Date: Apr 2004
Location: Atlanta, GA
Posts: 2,169
Default Re: Why don't they start right up?

Quote:
Originally Posted by QB93Z View Post
It could be because the Crankshaft has to rotate until the Ignition Module gets a signal from the Crankshaft Position Sensor so it can determine the correct ignition timing.

Jim
This is what I have read also crank needs to make one complete revolution, but it may also have something to do with were the sensor is at shut down.
__________________
Steve

1990 Steel Blue/Black #2355
1990 Red/Red #1473
1991 Quasar /Black #118 Sold
1991 Turquoise/Black #766 Parted Out
1993 Yellow/White #179 Sold
1990 Black/Gray #1361 Headers/4:10s Sold
We Gone is offline   Reply With Quote
Old 07-21-2014   #7
Fully Vetted
 
Fully Vetted's Avatar
 
Join Date: Sep 2012
Location: Rockwall, Tx
Posts: 1,504
Default Re: Why don't they start right up?

It could just be in my head but I've noticed it seems to fire quicker when I turn on the ignition and wait a couple of secs before engaging the starter.
__________________
_________________

1994 AB/Grey #141

430 RWHP/392 RWTQ

FBI Lyposuction / Secondaries relieved of duty / SW Long Tube Headers / Corsa Exhaust / FIC SS Injectors / MSD Coils / Lightweight Pulleys / Corey tuned
B & M Shifter / Aluminum Flywheel / Samco Hoses / Shelby Series One's / C4 No Flex Frame Stiffener

BBC - Bling By Carter:
Custom ZR-1 Center Caps / Custom Plenum Plate / Air Box Knobs / TB Cover / Oil Filter Cover
Fully Vetted is offline   Reply With Quote
Old 07-21-2014   #8
USAZR1
 
USAZR1's Avatar
 
Join Date: Oct 2013
Location: Wichita Falls,Tx
Posts: 594
Default Re: Why don't they start right up?

Quote:
Originally Posted by Fully Vetted View Post
It could just be in my head but I've noticed it seems to fire quicker when I turn on the ignition and wait a couple of secs before engaging the starter.
I've noticed this,too.
USAZR1 is offline   Reply With Quote
Old 07-21-2014   #9
BigJohn
 
BigJohn's Avatar
 
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,301
Default Re: Why don't they start right up?

Try starting my 32!
BigJohn is offline   Reply With Quote
Old 07-21-2014   #10
Fully Vetted
 
Fully Vetted's Avatar
 
Join Date: Sep 2012
Location: Rockwall, Tx
Posts: 1,504
Default Re: Why don't they start right up?

My Dad's '31 Model A starts so fast we had a standing challenge: If you can engage the starter at all and it not start he would buy dinner.

He never bought dinner....
__________________
_________________

1994 AB/Grey #141

430 RWHP/392 RWTQ

FBI Lyposuction / Secondaries relieved of duty / SW Long Tube Headers / Corsa Exhaust / FIC SS Injectors / MSD Coils / Lightweight Pulleys / Corey tuned
B & M Shifter / Aluminum Flywheel / Samco Hoses / Shelby Series One's / C4 No Flex Frame Stiffener

BBC - Bling By Carter:
Custom ZR-1 Center Caps / Custom Plenum Plate / Air Box Knobs / TB Cover / Oil Filter Cover
Fully Vetted is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:12 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2025