Starting Time...

[BlackSheepz]

Hello again all, I was just wondering how long it takes most of your cars to start?

I've looked around the web a lot and I've seen a lot of different answers floating around. (1 second -15 seconds i've read is normal but that seems weird).

In any of the videos I've found on youtube most of the ZR-1s start 1-3 seconds after the key is turned. I've been counting when I've started mine and it usually takes 4-6 seconds to start, but it does it every time. When I first got the car it seemed like it took FOREVER to start, but now the 5 seconds doesn't seem so bad.

Is my 5 second start time a problem? If it's a problem what potential problems could this be?

Injectors starting to go? (have them in a box with the gaskets just need to find the time)

Battery just getting tired maybe? (it's from 2013 it says, but the car wasn't driven much before me)

Starter?

Car starts just fine, the 4-6 seconds seems like a long time though.

Thanks in Advance!

Marc

[Karl]

Mine takes about 2 - 4 seconds to start. The longer it sits the longer it takes to start. I just started my car as I type this and it took about 1.5 seconds.

My new optima battery seems to help.

[efnfast]

I believe there is a 4 second delay before starting. Before I did my starter, injectors, coils and wires, my car used to start with a crack when I hit the key, I loved it. Hit the key and it snapped right to life. After changing the parts, it cranks longer and just starts. Before I changed parts, there was no 4 second delay. The only other change was the chip was reprogrammed because I also did a ported plenum and IH.

[ghlkal]

Car starts just fine, the 4-6 seconds seems like a long time though.


While I haven't timed mine, I believe it is about 5 seconds or so. I agree that it seems strange, but it doesn't seem out of the ordinary for a ZR-1

[BigJohn]

I never thought about it!

Do you count how many seconds it takes for a traffic light to change to GREEN?

[rush91]

If mine sits for a week (every weekend I start it rain or shine) it fires right up.....Maybe 1 or 2 seconds. Same thing if I drive it everyday, in the morning it fires right up, and goes to idle very quick. Now if I'm driving it all day, and stop at a gas station or somewhere for a few minutes, it will crank for about 3 seconds before firing up. Never any longer. I noticed once the engine is really warm, it takes longer, but that is to be expected.

[Dynomite]

It usually takes 3 seconds and never over 4 seconds to start (very little chain slap)......it then takes about 2 seconds for oil pressure to reach 75 lbs.....after warmed up oil pressure 50 lbs at idle.

On idling down to 750/800 another 3 seconds with Haibeck Chips in ALL.
Thermostat in 95' starts to open at 195 deg and replaced that with 180 deg thermostat that starts to open at 175 deg (180 deg Thermostat in ALL).


And......I use the Battery Disconnect Switch on ALL
With the Battery Disconnect you can Disconnect your Battery as often as you like without wearing out the Original Battery Negative Terminal on either the Battery or on the Negative Cable Connector.

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/9b113ff3-2c27-4600-aba8-a9f3456647a4.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/04ee613c-938d-4097-8632-8ae82f07897f.jpg

[BlackSheepz]

Thanks all, I feel better about it now.

I asked as my 92 LT1 starts up almost instantly and I knew there was a slight delay starting the Z but it seemed long. it also never seemed to be quite the same amount of time so I started keeping track.(loosely).

Dynomite, where did you get the battery quick disconnect? Thanks!

[We Gone]

The LT5 has to find #1 on the crank before it starts, so of the time depends on were it stopped along with what others have stated.

[RussMcB]

The LT5 has to find #1 on the crank before it starts, so of the time depends on were it stopped along with what others have stated.That's interesting. Is the LT5 unique in that respect? I've wondered why it seems to take longer to start than most EFI cars.

After I mentioned it to someone once they replied, not a bad thing - a little more time to build oil pressure. :-)

[PhillipsLT5]

I usually turn key to on but not start for a couple of seconds prior to turning key all the way/starting to let fuel pumps pressurize

[XfireZ51]

It usually takes 3 seconds and never over 4 seconds to start (very little chain slap)......it then takes about 2 seconds for oil pressure to reach 75 lbs.....after warmed up oil pressure 50 lbs at idle.

On idling down to 750/800 another 3 seconds with Haibeck Chips in ALL.
Thermostat in 95' starts to open at 195 deg and replaced that with 180 deg thermostat that starts to open at 175 deg (180 deg Thermostat in ALL).


And......I use the Battery Disconnect Switch on ALL
With the Battery Disconnect you can Disconnect your Battery as often as you like without wearing out the Original Battery Negative Terminal on either the Battery or on the Negative Cable Connector.

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/9b113ff3-2c27-4600-aba8-a9f3456647a4.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/04ee613c-938d-4097-8632-8ae82f07897f.jpg

Not a fan of those. They get loose and a bit worn. I was stranded once by one of those.

[Dynomite]

Dynomite, where did you get the battery quick disconnect? Thanks!

The Battery Disconnect Switch TIPS (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587653767)

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/9b113ff3-2c27-4600-aba8-a9f3456647a4.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/04ee613c-938d-4097-8632-8ae82f07897f.jpg

Side Mount Battery Disconnect Switch (http://www.ebay.com/itm/SIDE-MOUNT-BATTERY-TERMINAL-BATTERIES-CUT-OFF-DISCONNECT-SAFETY-SWITCH-/331185335836?hash=item4d1c2f2e1c&vxp=mtr)

Not a fan of those. They get loose and a bit worn. I was stranded once by one of those.
Too bad for you :dontknow:

I use the Side Mount Battery Disconnect Switch on ALL Corvettes with no issues. Batteries are always full charge as I disconnect battery with this Disconnect Switch if Corvette sits for more than a couple days :thumbsup:

[Hib Halverson]

There is no four-second delay in the starting sequence of the LT5.

That said, unlike some other EFI engines, the LT5 has to crank long enough for the cam sensor to signal the ECM where the engine is in the firing order. Once the ECM "knows" where TDC #1 is, it enables the injectors and ignition.

LT5 was the first GM engine with SEFI. The next one didn't come along until 1994 when increasingly stringent exhaust emissions standards had GM making the LT1 an SEFI engine. In four years, technology advanced such that SEFI LT1s didn't need the long crank time.

But...if your engine is needing to crank for longer than a couple of seconds before it lights, the first thing I'd do is run the fuel pressure tests listed in the Factory Service Manual because, sometimes, excessive time cranking is indicative of either failing ball check valve or valves in one or both fuel pumps or leaking injectors.

As for turning the key to on to let the fuel pumps prime, know that the ECM shuts the pumps off after a couple of seconds if it does not get a signal that oil pressure is building. If you really want to "prime" the fuel rail after a long period of non-op, you have to turn the key on, then off several times, with a break in between key ups, to get the pumps to run enough two-second "bursts" to prime the system.

It was said that 92 LT1s start-up quick. Well...yeah, they do because they are not SEFI engines. Like the L98s before them, 92 and 93 LT1s are "batch-fire" EFI engines.

Lastly, if you think your battery is "tired", have it tested. If it's weak, replace it with the best battery in the aftermarket, an Odyssey Battery (http://www.odysseybattery.com). I had an Odyssey 75-PC1230 in my '95 when I sold it and it had been there for six years before that. You put an Odyssey in your ZR-1 and, while there still be a crank time longer than newer SEFI engines, the crank speed will be higher because the Odyssey has a much higher "pulse-cranking" rating than any Delco or even the well-marketed (but over-rated) Optimas.

[Hog]

The Battery Disconnect Switch TIPS (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587653767)

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/9b113ff3-2c27-4600-aba8-a9f3456647a4.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite11/04ee613c-938d-4097-8632-8ae82f07897f.jpg

Side Mount Battery Disconnect Switch (http://www.ebay.com/itm/SIDE-MOUNT-BATTERY-TERMINAL-BATTERIES-CUT-OFF-DISCONNECT-SAFETY-SWITCH-/331185335836?hash=item4d1c2f2e1c&vxp=mtr)


Too bad for you :dontknow:

I use the Side Mount Battery Disconnect Switch on ALL Corvettes with no issues. Batteries are always full charge as I disconnect battery with this Disconnect Switch if Corvette sits for more than a couple days :thumbsup:
I think you lose your fuel trims every time you power down the ECM?

[Hog]

I usually turn key to on but not start for a couple of seconds prior to turning key all the way/starting to let fuel pumps pressurize

Does priming the fuel system decrease your crank times?

[Hib Halverson]

I think you lose your fuel trims every time you power down the ECM?

Depends on what you mean by "power down".

If you mean, turn off the ignition, the answer is "Yes." for short term trim (ie: integrator) and "No." for long term trim (ie: block learn).

If you mean, turn off the ignition and disconnect the battery for at least 15 seconds, then yes, you loose all fuel trim information and you start from zero for both STFT and LTFT.

Also, just so we're all on the "same page", the above is true for all ZR-1s and any GM vehicle from 81-95.

[Hib Halverson]

Does priming the fuel system decrease your crank times?

If you have leakage somewhere in the fuel system or the period of non-operation has been long enough for the fuel pressure to slowly bleed off, the answer would be "Yes".

[BlackSheepz]

Lot of good info in this thread, really appreciate it.

As an update, I started the car last night and it took 7 seconds to turn over and start. Today I got out the battery tester and the battery lit up as Fair. The battery was stickered 6/2013 and while it should have still been good I decided to just replace it anyway. (The battery in my 92 is stickered the same and lit up like a Christmas tree when I tested it.)

Ended up putting a Duralast Gold in there. Hib I greatly appreciate the Odyssey suggestion but I'm not going to lie $300 for a battery seems a bit much to me.

Started up in just under 3 seconds. I feel much better about the whole thing now.

Injectors are still high on the To Do list. Just got to find a free weekend to do them now.

Thanks again! :cheers:

[RussMcB]

<snip>... but I'm not going to lie $300 for a battery seems a bit much to me.I was able to get one last month for $234, which seemed reasonable considering the specs and reputation. I shopped around (maybe via Amazon?), and ordered one from 4wheelparts.com. My car is starting a little faster now (but still 1-2s longer than my other cars).

A side note: I have a FP gauge and my fuel pressure stays pretty high while shut down. Maybe I'm lucky to not have much bleed off.

[Hog]

Depends on what you mean by "power down".

If you mean, turn off the ignition, the answer is "Yes." for short term trim (ie: integrator) and "No." for long term trim (ie: block learn).

If you mean, turn off the ignition and disconnect the battery for at least 15 seconds, then yes, you loose all fuel trim information and you start from zero for both STFT and LTFT.

Also, just so we're all on the "same page", the above is true for all ZR-1s and any GM vehicle from 81-95.
Since powering down the ECM involves disconnecting its power source, AKA disconnecting the battery, that's what I was asking/pointing out. I was specifically quoting a post that said that powering down the car had no issues or something to that effect, and had pictures of a sidepost battery disconnect appliance.

[Hog]

If you have leakage somewhere in the fuel system or the period of non-operation has been long enough for the fuel pressure to slowly bleed off, the answer would be "Yes".

I was asking about a specific car.

[Hog]

LT5 was the first GM engine with SEFI. The next one didn't come along until 1994 when increasingly stringent exhaust emissions standards had GM making the LT1 an SEFI engine. In four years, technology advanced such that SEFI LT1s didn't need the long crank time.

.There are GM engines which were SFI before the LT5, the 1984+ Grand Nationals with the 3.8 were all SFI engine with the wasted spark ignition system. Similar in appearance to the LT5 and Northstar ignition hardware.
The Buicks were known to have similar extended crank times.

[Hib Halverson]

There are GM engines which were SFI before the LT5, the 1984+ Grand Nationals with the 3.8 were all SFI engine with the wasted spark ignition system. Similar in appearance to the LT5 and Northstar ignition hardware.
The Buicks were known to have similar extended crank times.

You are right "Hog"! My statement as keyed-in is incorrect.

All the GNs had SEFI V6es. I thought I'd typed that the LT5 was GM's first SEFI V8, but I didn't.
Oops.