fuel issue

[99boostedgst]

i own a 95 gst of course been having alot of issues which some of you guys have helped me with, thank you very much btw, heres my final question i hope, i was going to FINALLY tune but got stoped in my tracks, i was going to the gas station started running a little rich came under 5 pounds of boost when i let off it died, thought it was the ignition again, well realized i had no spark,fuel injector pulse, and no fuel pump.... what would of caused this? i have hot wired the pump to get my 40 psi of fuel pressure and i can crank but no fire... i have checked the relays under the dash and it was good,

so basically my question is what do you guys think? and a mod edit is went from the 1050 cc injectors to 750's and it helped alot!!!

thanks in advance
dustin.

 

[JusMX141]

Why are you changing injectors around without actually dialing in whatever injectors you have installed?

Who knows what is causing the issue at this point, but I'm 99% sure it's tuning-related based on your ability to drop 300cc of injector size and notice an improvement in the car's driveability.

 

[luv2rallye]

...heres my final question i hope...

(sorry couldn't resist)

 

[thearkatek]

Check your CAS and/or CAS connection. If the computer doesn't see any signal from the CAS I don't think it will put out any signal to the injectors or ignition. Although I don't know how that would affect the fuel pump.

 

[luv2rallye]

ECO also needs to see CAS pulses to enable the fuel pump.

 

[thearkatek]

Bam! definitely check to see if you're getting a signal from your CAS.

 

[99boostedgst]

Why are you changing injectors around without actually dialing in whatever injectors you have installed?

Who knows what is causing the issue at this point, but I'm 99% sure it's tuning-related based on your ability to drop 300cc of injector size and notice an improvement in the car's driveability.

we went in and changed it on dsmlink, but it cranks over but even with pump hot wired theres no fire..

(sorry couldn't resist)

and the reason behind this is because when its running i have it sold so thats why i said hopefully the last time

Check your CAS and/or CAS connection. If the computer doesn't see any signal from the CAS I don't think it will put out any signal to the injectors or ignition. Although I don't know how that would affect the fuel pump.

okay sorry man i dont know what the CAS is and ECO as stated by luv2rallye

ECO also needs to see CAS pulses to enable the fuel pump.

thanks guys for the help... i will be back in a dsm but hopefully this time i dont find such a piece of sh!t this time... this car has been rode hard and never put away wet .

 

[Pupdeck]

CAS is the cam angle sensor. Also if you are running a 7-bolt engine with 7-bolt sensors if the crank sensor is not sending signal to the ecu it will also not pulse injectors and will not spark. Common when a 7-bolt crank walks. Not sure of your setup but sounds like the probable issue is either cam or crank
Sensor signals.

 

[thearkatek]

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Thats the CAS. It has 4 pins and you should see pulses on three of them when the engine is turning over.

 

[99boostedgst]

i have the little black cam sensor i have replaced it and still nothing so took it back got 65 bucks back but imma try a crank sensor and see if that works, thats what me and my friend were thinking if the crank sensor is not working it wont send the current to the ecu and tell it to work, but i wanted to check with you guys and see what your thoughts were..

oh and pupdeck also it a 95 body and harness with a 97 motor, so the cam sensor was under the cam gear on the 95 motor, and the 97 is where thearkatec showed but its the small black one, i have spliced the wires to connect the cam sensor to the harness, (i sodered the connections i have checked them and there still connected.

thanks again guys with the fast responces.
dustin.

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Thats the CAS. It has 4 pins and you should see pulses on three of them when the engine is turning over.

what type of fuel rail are you running? the thing looks beefy i had a magnus on mine but traded it for some other goodies didnt really need it so i was like i dont care

 

[thearkatek]

sorry dude I just Googled CAS instead of walking out to my car and taking a picture.

 

[99boostedgst]

oh your fine man.... and also update i replaced the crank sensor and still nothing... and also checked for spark, there wasnt any. planning on checking fuel pulse with a test light tomrrow, also plan on sticking it on dsmlink and try to engage the fuel pump by computer, if it does kick on what do you think it could be.... i can hot wire the fuel pump and get my 40 psi of fuel pressure but still nothing after doing so.... hoping to get it running again i have a few lt-1 firebird and ls-1 ss that keep talking sh!t on my car saying its slow and i wanna show them what it has before i sell it

thanks
dustin

 

[luv2rallye]

This may be obvious but did you check the "Engine" (or MFI) fuse under the hood which provides power to the MFI relay which powers the ECU?

If the CEL doesn't come on when you turn the ignition on and go off 5 seconds later then the ECU isn't working (it also sets the boost gauge to read 0). Are you getting this?

 

[talon2gbuyer]

sorry dude I just Googled CAS instead of walking out to my car and taking a picture.

you lazy ass..

 

[99boostedgst]

This may be obvious but did you check the "Engine" (or MFI) fuse under the hood which provides power to the MFI relay which powers the ECU?

If the CEL doesn't come on when you turn the ignition on and go off 5 seconds later then the ECU isn't working (it also sets the boost gauge to read 0). Are you getting this?

ill double check it and my boost guage goes to -2 or -3 cant be exact because it a glow shift junk piece of sh!t .. but i will surely check it... thanks and ill get back to you on the status