Home page
SPONSOR AD

Topic: 90 Vette won't start

in Forum: C4 General Discussion

90 Vette won't start

Posted: 10/4/11 8:01am Message 1 of 25
Profile Pic
Standard Member
Send PM
Spring Grove, PA - USA
Joined: 7/25/2011
Posts: 18
Vette(s): 1992 Black Rose Coupe
Got fuel pressure 42 lbs. at rail, got spark to multiple plugs and air still wont start, could it be the ignition module or coil even though there is spark, my 92 had spark but was told not enough, turn out i had to change good ole Optispark do 90 vettes reqiure the same amount of spark to fire up


http://www.c4vetteregistry.com/member_uploads/15301_15400/15383/67-Pro20121027182550r.jpg

Vette2100
SPONSOR AD:: (Our Sponsors help support C4VR)

Re: 90 Vette won't start

Posted: 10/4/11 10:19am Message 2 of 25
Profile Pic
Standard Member
Moderator
Send PM
Duncanville, TX - USA
Joined: 3/18/2009
Posts: 2246
Vette(s): 1985 Coupe-L98/Auto,Bright Red/Carmine. 1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.
Gotta have spark, fuel, and air, at the right TIME.
You do need a good spark to fire off an engine. Have you checked your plugs for correct gap, fouling, or other problems?



Joel Adams  
My Link

 
   
(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Re: 90 Vette won't start

Posted: 10/4/11 1:12pm Message 3 of 25
Standard Member
Send PM
Joined: 2/26/2011
Posts: 82
vette2100 said: Got fuel pressure 42 lbs. at rail, got spark to multiple plugs and air still wont start, could it be the ignition module or coil even though there is spark, my 92 had spark but was told not enough, turn out i had to change good ole Optispark do 90 vettes reqiure the same amount of spark to fire up


How 'bout some more details. Did it cut off going down the road?  OR  One morning wouldn't start after being driven the previuos day ? Has any work been done on it recently and now it won't start? What do the plugs look like ? Wet or dry?
 
Since you have spark I'd try some starting fluid in the throttle body. If it runs w/starting fluid i'd use a noid light to check for pulse at the injectors while cranking since you have fuel pressure.
 
If it won't start w/starting fluid i'd guess spark is to weak to start (coil maybe??)  I say this under the assumption that nothing has been done to change spark timing such as loosening or removing the distributor recently.



Re: 90 Vette won't start

Posted: 10/4/11 1:14pm Message 4 of 25
Profile Pic
Standard Member
Send PM
Spring Grove, PA - USA
Joined: 7/25/2011
Posts: 18
Vette(s): 1992 Black Rose Coupe
Yeah plugs are good the car started ran for ten seconds then shut off, thats what my problem was with 92, had spark but not enough thats what i am wondering could it be the ignition module or if thay was no good would i get no spark at all


http://www.c4vetteregistry.com/member_uploads/15301_15400/15383/67-Pro20121027182550r.jpg

Vette2100

Re: 90 Vette won't start

Posted: 10/4/11 1:25pm Message 5 of 25
Standard Member
Send PM
Joined: 2/26/2011
Posts: 82

When the ign. modules fail you would loose spark. Once again starting fluid would check the entire ignition system....so to speak




Re: 90 Vette won't start

Posted: 10/4/11 2:39pm Message 6 of 25
Profile Pic
Standard Member
Send PM
Spring Grove, PA - USA
Joined: 7/25/2011
Posts: 18
Vette(s): 1992 Black Rose Coupe
tried starting fluid fires n thats it so i guess its getting spark, i have heard that if even one injector is bad the car wont start


http://www.c4vetteregistry.com/member_uploads/15301_15400/15383/67-Pro20121027182550r.jpg

Vette2100

Re: 90 Vette won't start

Posted: 10/4/11 2:40pm Message 7 of 25
Profile Pic
Standard Member
Send PM
Spring Grove, PA - USA
Joined: 7/25/2011
Posts: 18
Vette(s): 1992 Black Rose Coupe
nothing was done car arn fine then went to start it one day and it ran for ten seconds and shut off, wont start now


http://www.c4vetteregistry.com/member_uploads/15301_15400/15383/67-Pro20121027182550r.jpg

Vette2100

Re: 90 Vette won't start

Posted: 10/4/11 4:01pm Message 8 of 25
Standard Member
Moderator
Send PM
lanoka harbor, NJ - USA
Joined: 3/22/2009
Posts: 1363
Vette(s): 1990 L-98 white/ red/black leather interior targa top auto 1975 L48 blue/black leather interior t tops auto
could it be the fuel pump relay?




















the dynamic duo


c3vr life member #97

Re: 90 Vette won't start

Posted: 10/4/11 4:06pm Message 9 of 25
Standard Member
Send PM
Joined: 2/26/2011
Posts: 82
vette2100 said: tried starting fluid fires n thats it so i guess its getting spark, i have heard that if even one injector is bad the car wont start

Yours pulses 4 injectors at one time (what some call batch fired)...the ECM has 2 injector drivers each driver running 4 injectors..so if one injector is bad the "driver" won't operate any of the 4 on that circuit. If you have a VOM check the resistance on each injector I think they should read around 16 ohms..that may vary a little depending on your meter. The point is the readings of all should be close to the same. if you have one reading 3-4 ohms or one reading 48 ohms those injectors are bad and all should be replaced. If the readings are good you're back again IMO to checking for pulse at the injector connectors w/a  noid light Thumbs Up


Re: 90 Vette won't start

Posted: 10/4/11 5:45pm Message 10 of 25
Profile Pic
Standard Member
Send PM
Spring Grove, PA - USA
Joined: 7/25/2011
Posts: 18
Vette(s): 1992 Black Rose Coupe

Alright thanks ill give that a go tomorrow morning and let you know what I come up with, nothing like spending vacation days working on other peoples car huh?Really would like to get this running the weather finally got nice around here perfect for cruising Got mine running perfect and cant go, Thanks again




http://www.c4vetteregistry.com/member_uploads/15301_15400/15383/67-Pro20121027182550r.jpg

Vette2100

in Forum: C4 General Discussion


SPONSOR AD: (Our Sponsors help support C4VR)