Heres a odd one (starting issue)
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Joined: Sep 2007
Posts: 59
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From: Spring Hill Florida
Heres a odd one (starting issue)
Hey guys, great site, just got our first Vette, a 89. Guy was straight up honest when selling, the car randomly and instantly cuts out, generally at idle.
He has replaced, fuel pump,filter,injectors,ecm, battery,alternator.
I did some searching on here, and thought perhaps the vats1 was/is acting up so we bought a new key. Car ran flawless for a week, but now the issue is back.
Heres the odd part, when it dies and wont fire, pop open the clamps at the throttle body, spray a bit of starting fluid up there, close it up, and over she fires????? HUH???
I dont have the manual yet, and have not pulled any codes nor currently have the means, but any ideas would be greatly appreciated. Thanks, Shawn
He has replaced, fuel pump,filter,injectors,ecm, battery,alternator.
I did some searching on here, and thought perhaps the vats1 was/is acting up so we bought a new key. Car ran flawless for a week, but now the issue is back.
Heres the odd part, when it dies and wont fire, pop open the clamps at the throttle body, spray a bit of starting fluid up there, close it up, and over she fires????? HUH???
I dont have the manual yet, and have not pulled any codes nor currently have the means, but any ideas would be greatly appreciated. Thanks, Shawn
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Hey guys, great site, just got our first Vette, a 89. Guy was straight up honest when selling, the car randomly and instantly cuts out, generally at idle.
He has replaced, fuel pump,filter,injectors,ecm, battery,alternator.
I did some searching on here, and thought perhaps the vats1 was/is acting up so we bought a new key. Car ran flawless for a week, but now the issue is back.
Heres the odd part, when it dies and wont fire, pop open the clamps at the throttle body, spray a bit of starting fluid up there, close it up, and over she fires????? HUH???
I dont have the manual yet, and have not pulled any codes nor currently have the means, but any ideas would be greatly appreciated. Thanks, Shawn
He has replaced, fuel pump,filter,injectors,ecm, battery,alternator.
I did some searching on here, and thought perhaps the vats1 was/is acting up so we bought a new key. Car ran flawless for a week, but now the issue is back.
Heres the odd part, when it dies and wont fire, pop open the clamps at the throttle body, spray a bit of starting fluid up there, close it up, and over she fires????? HUH???
I dont have the manual yet, and have not pulled any codes nor currently have the means, but any ideas would be greatly appreciated. Thanks, Shawn
....pulling the codes can be done with a paper clip at the aldl...do that and get back to the forum with the results....
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You don't make it clear if spraying starter fluid allows the engine to start and run continuously. If it starts and runs until the starter fluid is gone, then you clearly have a fuel delivery problem. If it cranks, you don't have a VATS problem! If you can crank it and it won't start, then use your timing light to see if you have spark and spark at the right time. Use a fuel pressure gauge on the shrader valve on the end of the fuel rail to see if you have 40 psi and that the pressure doesn't drop rapidly with the ign off (leaky injectors). Buy a noid light or use a low powered 12v lamp like a side marker lamp and unplug an injector and connect the lamp across the injector plug and see if it pulses during cranking to see if the injectors are being pulsed. You can connect a paper clip across the top right two pins on the ALDL socket with the ign in run and the service engine light will flash 12 12 12 (that is, flash.........flash flash) followed by any stored codes.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
I'm wondering if the fuel pump relay has a problem.....
Best pull the codes before you spend any more money.
Its too easy to avoid doing.
Best pull the codes before you spend any more money.
Its too easy to avoid doing.
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
You don't make it clear if spraying starter fluid allows the engine to start and run continuously. If it starts and runs until the starter fluid is gone, then you clearly have a fuel delivery problem. If it cranks, you don't have a VATS problem! If you can crank it and it won't start, then use your timing light to see if you have spark and spark at the right time. Use a fuel pressure gauge on the shrader valve on the end of the fuel rail to see if you have 40 psi and that the pressure doesn't drop rapidly with the ign off (leaky injectors). Buy a noid light or use a low powered 12v lamp like a side marker lamp and unplug an injector and connect the lamp across the injector plug and see if it pulses during cranking to see if the injectors are being pulsed. You can connect a paper clip across the top right two pins on the ALDL socket with the ign in run and the service engine light will flash 12 12 12 (that is, flash.........flash flash) followed by any stored codes.
Instructor
Joined: Jul 2007
Posts: 222
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From: Toronto(Don Mills) Ontario
When my 86 had a similar problem, I had the same impression from studying my FSM, that the oil pressure switch would/should keep the car/FP running? It would not, under certain circumstances( e.g.- at low/idle speeds, or when coasting down to a stop). My problem then was definitely a bad or corroded FP relay. Putting a new relay in banished the problem immediately, and so far(3 years!) permanently.
Safety Car
Joined: Jul 2004
Posts: 3,845
Likes: 30
When my 86 had a similar problem, I had the same impression from studying my FSM, that the oil pressure switch would/should keep the car/FP running? It would not, under certain circumstances( e.g.- at low/idle speeds, or when coasting down to a stop). My problem then was definitely a bad or corroded FP relay. Putting a new relay in banished the problem immediately, and so far(3 years!) permanently.
..the oil pressure switch "kicks in" at 4lbs and that is attainable while cranking and at any speed that the engine is running....if the poster wants to change out the fp relay after checking the fuses, that's cool too.....
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Instructor
Joined: Jul 2007
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From: Toronto(Don Mills) Ontario
Oh I agree - that is what my Helms/FSM manual says/said! But be that as it may, my trouble was definitely the FP RELAY! Even my Chev Dealership said the same thing, and when I asked the mechanic there about the seeming disconnect with what the Helms says about this - he had no explanation? Btw, nothing else(besides the new Relay) was done - and no codes either!? I am not suggesting this is a cure all, but from my experience for similar(mysterious?) issues, it is worth checking out, despite what HELMS says. Ciao!
Last edited by Can86Z51; Sep 23, 2007 at 08:40 AM. Reason: missing word
Team Owner
Joined: Jan 2003
Posts: 20,320
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From: Summerland B.C. Canada
If the oil pressure switch is bad, he is relying on the relay. If that has intermittent problems, than he could have the problems he is having.
Take a look at the relay's connector. My wire insulation shrunk back an inch on all wires, allowing a good chance for shorts and intermittent operation. You may be experiencing this.
Instructor
Joined: Jul 2007
Posts: 222
Likes: 0
From: Toronto(Don Mills) Ontario
If the oil pressure switch is bad, he is relying on the relay. If that has intermittent problems, than he could have the problems he is having.
Take a look at the relay's connector. My wire insulation shrunk back an inch on all wires, allowing a good chance for shorts and intermittent operation. You may be experiencing this.
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Thread Starter
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Joined: Sep 2007
Posts: 59
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From: Spring Hill Florida
Thanks guys, ordered the Helms today (ouch!). Yes, when needed, the starting fluid starts and keeps the motor going. Will try the relay first, havent even looked for it yet. Also heard Igntion module could be bad as well. Only code is the "normal" 12 12 12 nothing else shows up. Will keep you up to date. Thanks for all the fast replies, Shawn
Last edited by sknight88; Sep 23, 2007 at 07:59 PM. Reason: spelling!
Safety Car
Joined: Jul 2004
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Thanks guys, ordered the Helms today (ouch!). Yes, when needed, the starting fluid starts and keeps the motor going. Will try the relay first, havent even looked for it yet. Also heard Igntion module could be bad as well. Only code is the "normal" 12 12 12 nothing else shows up. Will keep you up to date. Thanks for all the fast replies, Shawn
***EDIT..run 12vdc to terminal g on the aldl....
Last edited by Da Mail Man; Sep 23, 2007 at 08:04 PM.
Safety Car
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......lower left of/on aldl.........goodnight, goodluck...
Last edited by Da Mail Man; Sep 23, 2007 at 10:42 PM. Reason: additional...
Team Owner
Joined: Jan 2003
Posts: 20,320
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From: Summerland B.C. Canada
Here is some help from my 86 FSM http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
The 89's relay is wired different, so here is the schematic that gives the 89 relay in/outs.
The 89's relay is wired different, so here is the schematic that gives the 89 relay in/outs.
Thread Starter
Advanced
Joined: Sep 2007
Posts: 59
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From: Spring Hill Florida