1991 #614 back from grave but no start, cranks just fine - ZR-1 Net Registry Forums

MRCFOUR · 10-13-2023

Hello Z family! So, as you all know, #614 has been in reassembly mode since November of 2022. So, this week we decided to try and get it running. After, tear down of PS header to replace and reposition gasket so that the manifold studs could be installed, various mystery leaks involving the V drain tube, repair and verify all secondary vacuum hoses, removal and cleaning of contacts in starter, replacing ignition coils (verified spark at all 8 plugs), verifying of fire order, removal and testing of alternator, replacement of spark plugs and fuel filter and new single pump from DL Merrill (now have 50-55psi at crank with 45 and eventually lower after crank) setting of TPS voltage, and 2 different PROM chips we are at this stage?. Cranks, does not run unless throttle pedal is lightly feathered, back fire out of headers and TB, smoke puffs out of TB during cranking. Any insight would be greatly appreciated. This car has been off the road since 2019 and was bought in pieces so to be here at this stage is simply a marvel.

HELP! We are at our knowledge base limit and do not know what else to do. Replacement of injectors will be our next step unless this is something silly we are missing.

Thanks so very much!

secondchance · 10-14-2023

I would double check and make sure spark plug wires are connected to correct coil terminal.

viper107 · 10-15-2023

Check fire order also

viper107 · 10-15-2023

Also if you have a different ecm try that, they junk

MRCFOUR · 10-15-2023

Quote:

Originally Posted by viper107

Check fire order also

Yes, firing order was gone over many times during plenum install. I have the OE wires that are numbered. Made it easier.

MRCFOUR · 10-15-2023

Quote:

Originally Posted by viper107

Also if you have a different ecm try that, they junk

I?m trying to locate one to do just that. In the meantime, I?m sending mine to Marc to see what?s what with it.

Thanks for the ideas!

Chris

MRCFOUR · 10-15-2023

Quote:

Originally Posted by secondchance

I would double check and make sure spark plug wires are connected to correct coil terminal.

Thanks. This was gone over many times prior to plenum install. Used the FSM diagrams and I have the factory numbered wires.

tpepmeie · 10-15-2023

Chris, I have an ECM I can loan you. I may be down your way in the next week.

Sent from my iPhone using ZR-1 Net Registry

MRCFOUR · 10-15-2023

Quote:

Originally Posted by tpepmeie

Chris, I have an ECM I can loan you. I may be down your way in the next week.

Sent from my iPhone using ZR-1 Net Registry

This would be fantastic! I?d really like the opportunity to see if indeed that is the issue! If you know when you?d be down this way, we could just plug it in and see what happens!

Chris

phrogs · 10-19-2023

If the Different ECM doesn't work bring it to me ill take it off your hands. haha

Anyway how disassembled was this car when you got it? Is there any chance there's a issue with camshaft timing?

Injectors could really be an issue, I had a set of FICs on the shelf for a few years when I went to use them in my abandoned ZR-1 one of them decided to leak. like just a faucet of fuel dumping out of it, Of course I failed to double check them so I had to yank them out and test them and that's how I figured it out. with no input from the car other than fuel pressure. So perhaps you have a leaker or not even spraying. Of course the ECM could be the issue but I would have your injectors tested. If you want to send them to me I could do it see what they are doing before you buy new ones.

10-13-2023	#1
MRCFOUR Join Date: Feb 2017 Location: Owensville Indiana Posts: 71	1991 #614 back from grave but no start, cranks just fine Hello Z family! So, as you all know, #614 has been in reassembly mode since November of 2022. So, this week we decided to try and get it running. After, tear down of PS header to replace and reposition gasket so that the manifold studs could be installed, various mystery leaks involving the V drain tube, repair and verify all secondary vacuum hoses, removal and cleaning of contacts in starter, replacing ignition coils (verified spark at all 8 plugs), verifying of fire order, removal and testing of alternator, replacement of spark plugs and fuel filter and new single pump from DL Merrill (now have 50-55psi at crank with 45 and eventually lower after crank) setting of TPS voltage, and 2 different PROM chips we are at this stage?. Cranks, does not run unless throttle pedal is lightly feathered, back fire out of headers and TB, smoke puffs out of TB during cranking. Any insight would be greatly appreciated. This car has been off the road since 2019 and was bought in pieces so to be here at this stage is simply a marvel. HELP! We are at our knowledge base limit and do not know what else to do. Replacement of injectors will be our next step unless this is something silly we are missing. Thanks so very much! __________________ 1991 #614 Black/Saddle - still in rebuild stage since 2021 1992 Coupe Base White/White - ZF6 and a bunch of other modified stuff 1990 Convertible Black/Black/Black - slightly modified 1992 Coupe Black Rose - in and out 1993 Coupe Black Rose - also in and out

10-14-2023	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,703	Re: 1991 #614 back from grave but no start, cranks just fine I would double check and make sure spark plug wires are connected to correct coil terminal.

10-15-2023	#3
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 746	Re: 1991 #614 back from grave but no start, cranks just fine Check fire order also __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5

10-15-2023	#4
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 746	Re: 1991 #614 back from grave but no start, cranks just fine Also if you have a different ecm try that, they junk __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5

10-15-2023	#8
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 775	Re: 1991 #614 back from grave but no start, cranks just fine Chris, I have an ECM I can loan you. I may be down your way in the next week. Sent from my iPhone using ZR-1 Net Registry __________________ Todd ____________________________________ [SIGPIC][/SIGPIC] [email]pepmeierengines@yahoo.com[/email] [URL="http://toddpepmeier.wix.com/pepmeierengines"]visit our website[/URL] [URL="http://pepmeierenginedevelopment.blogspot.com/"]Blog[/URL] Friend us on Facebook too: [url="https://www.facebook.com/profile.php?id=100011443683384"] Pepmeier Engine Development[/url]

10-19-2023	#10
phrogs Join Date: Jul 2004 Location: Kalamazoo MI Posts: 1,738	Re: 1991 #614 back from grave but no start, cranks just fine If the Different ECM doesn't work bring it to me ill take it off your hands. haha Anyway how disassembled was this car when you got it? Is there any chance there's a issue with camshaft timing? Injectors could really be an issue, I had a set of FICs on the shelf for a few years when I went to use them in my abandoned ZR-1 one of them decided to leak. like just a faucet of fuel dumping out of it, Of course I failed to double check them so I had to yank them out and test them and that's how I figured it out. with no input from the car other than fuel pressure. So perhaps you have a leaker or not even spraying. Of course the ECM could be the issue but I would have your injectors tested. If you want to send them to me I could do it see what they are doing before you buy new ones. __________________ JOHNNY P Currently own 90 ZR-1 #845 DRM 500 engine package 90 #226 Might be a parts car not sure yet Last edited by phrogs; 10-19-2023 at 01:18 AM.