3-4 seconds and dies
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
Well, its not the IAC......replaced and still the same issue. I took a test light to the injector harness there is power there with the key on....
Any thoughts? not sure were shraeder valve is on the Callaway, tweaked the stock rail..
I am getting a spark signal with a test light on plug wire #1....
hmmmmmmm
Any thoughts? not sure were shraeder valve is on the Callaway, tweaked the stock rail..
I am getting a spark signal with a test light on plug wire #1....
hmmmmmmm
the book says to look for blinking light cranking. first, disconnect all inj harnesses, connect test light to one harness plug each side. if blinking then one route, not blinking, another.
I think with spark you have to have tach readings, so ref pulses from distr to fire injectors, but watch the tach when cranking anyway.
Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,917
Likes: 109
From: Crystal lake Il
2022 Corvette of the Year Winner -- Modified
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or are you saying you think its the wiring? If its a short would I have any power showing to them at all?
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
you wern't responding to my last post, were you? this isn't a fuel issue, seems to me. more likely an ECM or injector shorting issue, possibly TPS or MAf sensor. the clue is the short run time. a full fuel rail will run much longer.
if you remove fuses, you "short cut" eliminating one bank of injectors.
joe
if you remove fuses, you "short cut" eliminating one bank of injectors.
joe
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
lg, it would help to know to whom you are addressing your posts.
if to me, FORGET the oil pressure switch info. I don't have a 87 FSM but the 91 uses the oil switch as BACKUP, in the words of GM. most likley the earlier ones did too. besides the dash info is not the same switch.
if there is a short in the injectors or wiring, yes, the ecm shuts down inj drivers, sometimes after the first squirt.
*** backup to fuel pump, not to FP relay, direct to pump
if to me, FORGET the oil pressure switch info. I don't have a 87 FSM but the 91 uses the oil switch as BACKUP, in the words of GM. most likley the earlier ones did too. besides the dash info is not the same switch.
if there is a short in the injectors or wiring, yes, the ecm shuts down inj drivers, sometimes after the first squirt.
*** backup to fuel pump, not to FP relay, direct to pump
Last edited by joe paco; Sep 5, 2011 at 04:29 PM. Reason: add***
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
fsm has one whole section on checking voltage to injectors and cheking for a short in the grn or blu circuits. chart a-3 page 2.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Just to ask,
Are You sure the Mass Air Flow Sensor is firmly plugged in on 1987 Callaway TT ?
I have photos of the '87 TT & they use a MAF like my standard '87 Vert.
My car just about refuses to start if the MAF connector is left unplugged.
Another time my car died & refused to restart.
Start for 3- 4 seconds like yours & then just die.
I wiggled the MAF connector & my car fired right up.
Cleaned the connector & MAF sensor connector pins with fine 600 grit sandpaper.
Light coat of silicone dielectric grease applied with a "Q" tip on the terminals afterwards.
No Problems since.
Fires up easily every time.
Came up in the past here on C4 that the MAF sensor is not used at all for engine starting purposes.
But I beg to differ on my 1987 Vert.
I can hook up my Snap On Scanner & watch the MAF sensor start working as soon as the key- engine is cranked & Grams per second counts (3-6 grams/ sec) while the engine is rotating over with Delco 10 MT starter motor.
Also learned the last night the TOP C4 computer software experts are far from cracking all programs put in by the original group of C4 engineers.
ASC2 software programming ?
I had that in College Electronics for 2 years.
Drove me crazy.
Why I still hate computers half the time.
But I am caving in finally 20 + years later.
Brian
Are You sure the Mass Air Flow Sensor is firmly plugged in on 1987 Callaway TT ?
I have photos of the '87 TT & they use a MAF like my standard '87 Vert.
My car just about refuses to start if the MAF connector is left unplugged.
Another time my car died & refused to restart.
Start for 3- 4 seconds like yours & then just die.
I wiggled the MAF connector & my car fired right up.
Cleaned the connector & MAF sensor connector pins with fine 600 grit sandpaper.
Light coat of silicone dielectric grease applied with a "Q" tip on the terminals afterwards.
No Problems since.
Fires up easily every time.
Came up in the past here on C4 that the MAF sensor is not used at all for engine starting purposes.
But I beg to differ on my 1987 Vert.
I can hook up my Snap On Scanner & watch the MAF sensor start working as soon as the key- engine is cranked & Grams per second counts (3-6 grams/ sec) while the engine is rotating over with Delco 10 MT starter motor.
Also learned the last night the TOP C4 computer software experts are far from cracking all programs put in by the original group of C4 engineers.
ASC2 software programming ?
I had that in College Electronics for 2 years.
Drove me crazy.
Why I still hate computers half the time.
But I am caving in finally 20 + years later.
Brian
Last edited by 87 vette 81 big girl; Sep 5, 2011 at 05:44 PM.
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Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
per chart a-3, you can get a blinking light, no light, or a steady light when checking.
the charts for "no start" and "start but immediately dies" do not mention an intermittent ICM, but I suppose it can happen. cross your fingers....
at least we can conclude that it is not the oil switch, I reckon .
joe
Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,917
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From: Crystal lake Il
2022 Corvette of the Year Winner -- Modified
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I am still getting codes 42 and 34 through an SES...I am also guessing my spark plugs are toasted from trying to start the car so many times
Instructor
Joined: Jun 2011
Posts: 182
Likes: 0
From: Bowling Green Ky
not sure you can damage a plug by trying to start it. that does not compare to firing under pressures. is the est bypass connected secure?
add: "Still" getting codes? I thought there were no codes initially...the icam will not set a code,of course, but the MAP would have.
Last edited by stoydido; Sep 5, 2011 at 09:33 PM. Reason: add
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Turn the headlights on & leave them on.
Disconnect the Negative battery cable.
Leave it unhooked for about 5 minutes.
Reconnect the Negative battery cable.
Shut off your headlights.
Start your 1987 Callaway TT without touching the gas pedal & let idle & warm up fully till the coolant main fan turns on & back off on its own normal.
Might take a while to warm up fully to 195F- 205F water temp tonight here in Illinois.
Around 55- 60 F outside down by here in Peoria, IL.
Drive your Corvette afterwards normal & see if the code(s) come back or not.
False codes can be triggered by ignition module total failures.
Going for late night ride in my 87 Vert.
Have some fun on the backroads & highways here.
Brian
Disconnect the Negative battery cable.
Leave it unhooked for about 5 minutes.
Reconnect the Negative battery cable.
Shut off your headlights.
Start your 1987 Callaway TT without touching the gas pedal & let idle & warm up fully till the coolant main fan turns on & back off on its own normal.
Might take a while to warm up fully to 195F- 205F water temp tonight here in Illinois.
Around 55- 60 F outside down by here in Peoria, IL.
Drive your Corvette afterwards normal & see if the code(s) come back or not.
False codes can be triggered by ignition module total failures.
Going for late night ride in my 87 Vert.
Have some fun on the backroads & highways here.
Brian
Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,917
Likes: 109
From: Crystal lake Il
2022 Corvette of the Year Winner -- Modified
2021 C4 of the Year - Modified Winner
I only had the code 12 prior to the start up, I will check the est I was playing with alot trying to trace down the issue. More to come...wifey said enough car time today and was done about 4-5pm
Thanks everyone for the help
Thanks everyone for the help
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Vette checks out A- Ok & fully warmed up.
My fun time now..........waited alll weekend for my fun thrill ride.
Have fun too.
Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,917
Likes: 109
From: Crystal lake Il
2022 Corvette of the Year Winner -- Modified
2021 C4 of the Year - Modified Winner
Noooooooooooooo......back to were I started....runs 3-4 secs and dies. Ignition module tested as bad, replaced, but problem still lingers....maybe at this point plugs may be fouled.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
I would have stopped by with some of my own diagnostic equipment on hand.
I took my late night car ride to Chicago land late Monday night.
Hauled azz up there on the back roads.
Stopped by a few buds houses that are race crazy like me.
Then hauled azz home for more fun.
Love cruising at over 120 mph for 40 to 50 miles at a time.
Paid for it yesterday at work though.
Was tired all day.
Smiling this morning though
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
plugs are not the problem.
go back to post 6 or so, check for shorted wires or injector. the second clue was "wiggled wires, started."
wooohoooooo!
again, the fsm covers this in 4-6 pages of analyses.
Last edited by joe paco; Sep 7, 2011 at 08:23 AM. Reason: ***add also check post 30 or relevent pages in fsm on how to verify inj harness.........
Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,917
Likes: 109
From: Crystal lake Il
2022 Corvette of the Year Winner -- Modified
2021 C4 of the Year - Modified Winner
I pulled fuse for FI 1, car runs for 8 seconds and dies, pulled for FI2 and car stalls at 3-4.
I see 200 rpm on tach when cranking; which means ign module is working correct?
I guess next it to test pulse on each FI with a noid light?
I see 200 rpm on tach when cranking; which means ign module is working correct?
I guess next it to test pulse on each FI with a noid light?
Last edited by lgaff; Sep 7, 2011 at 08:20 PM.