metalhead212121

Well its that time again....cars running pretty good....life is going good ect ect. You all know what that means...time for a odd no start problem. Here it goes...this is on a 91 305 TPI motor

Get in my car today..turn the key...crank crank crank...wont start. Ok....turn the key crank crank crank. Same problem...wont turn over. Ok so this time Im listening for the fuel pump to prime the system. I hear the pump loud and clear. Now it starts..runs for a second and dies...this goes on for a couple more times before I give up and start looking around. Long story short I decided before I start touching stuff I should see if I have any codes. Scanned the computer and came up with VATS code. =( So I decide to use the other key. Starts right up. Problem fixed right?? Wrong...Go back and use the other key.. starts right up.. I really dont know what to think. My friend was telling me that the VAT system uses a whole security box and that this could very will be giving me trouble...any truth to this????????? Yes, one outta my two igition keys does look worn (im talking about the diode) but could this be the problem? I figured that if the diode wasnt giving the right amount of resistance the car wouldnt start at all. Right?????

The car has resently be "tuned up" by me. New plugs, wires, cap, rotor, coil, pick-up, and module. I have not yet timed the motor or changed the temp sensor due to time issues. I was thinking that MAYBE the temp sensor is reading outta range.....What do you guys think? Come monday morning Im gonna get a GM temp sensor and set the timing on my car just to get it over and done with. Yes I do realize that Im giving too much info on the car to solve this problem but Id rather give too much than the usuall help! cars wont run! whats the problem!!

TIA


Dan

Dan

bigals87z28

VATS= Vehicle Anti Theft System...
yea, if that key has a worn out whatever.... its not gunna start the car. Its just part of keeping your car safe!!! I dont know if they make them anymore (im sure they do) but i would get them replaced.

metalhead212121

I dont know Alex....Im not 100% sure thats ALL of my problem. Why would my car start and then die if the key was bad??? Regardless I really should get another set of keys (with diodes) made. Does anybody know how much it costs to get duplicate keys made from GM?



Dan

Tonyrodz

Had my key made by a GM dealer--costs $25 for it--but well worth it!

BFDPerformance

it makes sense.....if the key moves at all and loses the connection it will die....could happen :lala:

metalhead212121

well I talked to my boss about my problem. He was thinking that the problem is fuel related. Try to follow the theory on this....I only drive the car on weekends. Maybe the check valve(?) in the fuel pump isnt working correctly (according to my boss). Im not 100% sure about what he's talking about but his arguement was that as days go by the fuel in the lines isnt holding pressure and is going back into tank. Im gonna let the car sit a couple days and try to start it. If it doesnt start...the FIRST thing I'll do is put a fuel pressure gauge on it and see what the pressure reading is. If I can "cycle the key" and build pressure I think its pretty safe to say that the pump is on its way out. What do you guys think??

Also got some info on the VAT system. For starters..I dont know why I had a VAT code in my computer...I'll clear it and see if it comes back. IF my keys were giving me a problem the starter would NOT turn over. From what Ive been told...if the computer doesnt see the right resistance from the diode the car will not crank at all...let alone run for a second and die.
BFDPerformance~ while i had the car running I was able to wiggle the key ALMOST to the point where I could have taken it out of the ignition. So I think that disproves what you said...sorry.

I'll keep posting updates..

Dan