Need your ideas - LT5 won?t turnover

[lfalzarano]

The car has been in a shop for 3 months to repair the clutch hydraulics (master and slave cylinders) and replace the clutch. The battery was replaced last week, but the mechanic says nothing happens when he tries to start it (will not crank). The LT5 had no engine problems even after the transmission failures when I drove it last.

I know they must have moved the ECU when they replaced the clutch master cylinder. I also know that you have to disconnect the clutch pedal to the clutch master cylinder when replacing it.

Suggestion on a possible solution would be appreciated.


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[mlipmd]

Did they disconnect/reconnect the CSS?

[lfalzarano]

What is the CSS?

[Young1]

Clutch safety switch. Mounted on clutch pedal assembly up under hush panel

[viper107]

if they can pull a transmission the shurly can figure this out, no differant than any system

[tccrab]

Nothing special about the starter and ignition circuits, same as all other C4s.
It's not rocket surgery, any decent mechanic should know and understand and diagnose them with both eyes shut.
Vats does complicate it somewhat, but thats why theres diagnostic charts in the FSM.
Sounds like you need a new mechanic.

Crabs

[Young1]

It?s not necessary to move to remove the ECU, you just remove it from its bracket and flip it over out of the way. If they took all the clips out of the back of the eco and put them back in incorrectly that could be your problem. Again not rocket science.

[lfalzarano]

Clutch safety switch. Mounted on clutch pedal assembly up under hush panel



Thanks but that tested OK according to the mechanic.


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[DRM500RUBYZR-1]

1- battery voltage 12.5 plus
2- battery connections clean and tight
3- is it making it through the VATS ( were the two white wires in column harmed)
4- make sure a thicker floor mat is not preventing clutch going to floor
5- any deflection of voltage needle when key turned from on to start
6-unplug and replug ECM connectors if they had been removed
7- If ECM was removed, make sure chip is in firmly and correctly.
:cheers:
Marty

[Demps]

Marc Haibeck's site has his tips...I'd reference this: http://www.zr1specialist.com/HAT%20Web/articles/Diagnosing%20Starter%20Problems.pdf

Ted

[Mikey]

3 months??

Innovation Performance Technologies in Aberdeen, NC (near Pinehurst) is owned by a friend of mine.. might want to have them do future work. They're not LT5 gurus but anything else C4 is pretty much all the same and they are very competent. Ask for Jon or Crimson and tell them I sent you.

[tf95ZR1]

Keeping it simple (KISS) are they depressing
the clutch pedal all the way to the floor?
:)

[richarde]

It sounds as though the problem is linked to the Clutch Safety Switch, in particular the Clutch Neutral Start Switch Rod. As it can be difficult to bleed all the air from the clutch hydraulics after replacing both the master and slave cylinders, an over aggressive use of the clutch pedal (repeatedly side slipping it when fully depressed in an attempt to rid the system of air) can sometimes break / disengage the switch rod. This would lead the no start situation described. The part number of the Switch Rod is 14080260.

[-=Jeff=-]

Have you tried to unplug the clutch safety switch put a jumper across the terminals and try to start it? Also you can add a relay (in an older post here) that will use all the switches to power the relay then the relay runs from battery directly to the starter.

It is also possible the starter contacts are carbon covered but I think it is the CSS and related circuit

[lfalzarano]

Update, the mechanic did test the clutch safety switch Feb 4 and tested OK. He retested it again on the Feb. 21 and had to replace it. It starts fine now!

Thanks for all your suggestions and ideas. The mechanic at Chevy is questionable.

When I went to pick it up shifting was laborious and the clutch didn?t engage until an inch from the firewall. (This all started with the clutch hydraulics going out and shattered the clutch, which was the original repair request to the dealer!)

Add to that the idle wouldn?t come down below 2000rpm. It was impossible to drive with both conditions.

So it remains in the shop. [emoji20] we?re approaching the 4 month anniversary of no ZR-1[emoji35]


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[richarde]

So, the clutch pedal needs to be depressed to the floor before disengaging. A few suggestions spring to mind.
The most obvious one is whether the clutch hydraulics have been successfully bled to rid all air from the system.
Another visual check - both the clutch and brake pedal should be very close to being the same height from the floor when looking into the car. If the clutch pedal is appreciably lower than the brake pedal, the problem could be that the full stroke of the clutch master cylinder is not being obtained. If you find this to be the case, the reason could be a bent clutch pedal bracket or pushrod, or even an incorrect specification master cylinder. Having a new clutch with lots of meat on the centre plate can exaggerate this issue.
If the above checks out OK, moving to the clutch slave cylinder, ensure that it is of the correct specification for both bore size and stroke.




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[lfalzarano]

So, the clutch pedal needs to be depressed to the floor before disengaging. A few suggestions spring to mind.
The most obvious one is whether the clutch hydraulics have been successfully bled to rid all air from the system.
Another visual check - both the clutch and brake pedal should be very close to being the same height from the floor when looking into the car. If the clutch pedal is appreciably lower than the brake pedal, the problem could be that the full stroke of the clutch master cylinder is not being obtained. If you find this to be the case, the reason could be a bent clutch pedal bracket or pushrod, or even an incorrect specification master cylinder. Having a new clutch with lots of meat on the centre plate can exaggerate this issue.
If the above checks out OK, moving to the clutch slave cylinder, ensure that it is of the correct specification for both bore size and stroke.




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Thanks for your ideas. I?ve been forwarding your comments to the Chevy service manager.


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[lfalzarano]

Another mystery is why an apostrophe being replaced by with a ? mark on this forum?[emoji16]


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[A26B]

A bent clutch fork can also cause a low pedal disengagement. Bent and broken clutch forks are an infrequent but known occurrence in the ZR-1.

Lets see an apostrophe '', and a Question mark???
Showed up fine from my keyboard

[secondchance]

A bent clutch fork can also cause a low pedal disengagement. Bent and broken clutch forks are an infrequent but known occurrence in the ZR-1.

Lets see an apostrophe '', and a Question mark???
Showed up fine from my keyboard

Bent clutch fork happened to me about 10 years ago. Apostrophe being replaced with question mark happens when I use iPad for posting.

[lfalzarano]

A bent clutch fork can also cause a low pedal disengagement. Bent and broken clutch forks are an infrequent but known occurrence in the ZR-1.

Lets see an apostrophe '', and a Question mark???
Showed up fine from my keyboard

I'm using an iPhone and sometimes W10 laptop.

[lfalzarano]

Keeping it simple (KISS) are they depressing
the clutch pedal all the way to the floor?
:)

Yes, and it was still hard to shift gears.

[aafc]

I don't know if this helps you, but it got me home.
Before I changed from the zf gear box to an auto, I had no start while out
shopping. Would not turn over engine, Set park brake, car in neutral,
key to on position took a jumper wire and connected it to power then
touch to the purple wire direct to starter.
( car in neutral! when you do this )
Got car car started and drove home. As it turned out the
clutch safety switch had an open in the ckt.
my no start was not because of clutch repair. So not sure if this helps.

John
1990 white/black #2546
one of a few 4l8OE EQ R-1's

[Paul Workman]

It?s not necessary to move to remove the ECU, you just remove it from its bracket and flip it over out of the way. If they took all the clips out of the back of the eco and put them back in incorrectly that could be your problem. Again not rocket science.

Agree. But, too if they DID disconnect the ECU, there's the chance to bend one of the pins. But, an OBD-1 scanner would probably(?) pick up on that pretty quick. But, yeah. I can't imagine how changing the clutch hydraulics and hardware would affect anything to do with starting - ordinarily (that is).

I've come to hate taking my cars to anyone except a known GOOD mechanic...and they're darn few, it seems. And, DEALERS (aka parts swappers) especially! Like: when was the last time they worked on a ZR-1??? Was the mechanic even BORN when the car came out???

[lfalzarano]

Thanks to everyone. IT IS FIXED! A second mechanic found the Clutch safety switch was defective AND REPLACED IT. yeah!