VP only starts on second try

[MyVPIsFasterThanYourVP]

My VP only starts if i turn the key then stop, then turn the key again. Ive tried no throttle, half throttle, full throttle, but it will not start unless i turn the key twice. Its not the immobilizer, and the car runs sweet the rest of the time. Gregorys manual suggests that the fuel pump relay not working is a similar symptom, i.e. the car wont start until oil pressure is up..... I switched the relay with a good one, but no success. Its driving me crazy, I havent looked for a code, and i havent tried removing the main engine fuse to reset the computer.

[IBLOWN]

Maybe a problem with your key barrel.

[MyVPIsFasterThanYourVP]

no the engine turns over everytime, just wont start, unless i do it a second time, always!

[stocky]

mines started to do this a few times. i have a feeling its my fuel pump

[stockvp]

coil,leads and plugs?

[MyVPIsFasterThanYourVP]

please listen carefully.... I must turn the key 2 times to start the car. I must turn the key 2 times to start the car. Even if the first time is just almost only a click of the starter. The next time I turn the key it starts normally, and then runs PERFECT. It will not start the first time, no matter how long i crank it for.
With new spark plugs, wonderful acceleration, smooth power, great fuel economy, temp is normal, there is nothing about how the car runs to suggest any kind of problem. The starter cranks the engine with great enthusiasm, the starter works everytime, I am going nuts trying to understand this, and have tried to remove EVERY variable. PLEASE someone have found this problem and solved it, but just hidden it from the forum search, (and in fact from the almighty Google).
Colin

[Tekka]

in the mornings i purposely make my car start after 2 tries, coz i dont want the starter motor winding over coz shes cold, so i turn the key then let her off then turn again and she fires up nice straight away

[SweetWagon]

Might be a good theory you have there with the oil pressure switch, it does bypass the fuel pump fuse/relay when it has oil pressure, did you try the fuse aswell?

[MyVPIsFasterThanYourVP]

Might be a good theory you have there with the oil pressure switch, it does bypass the fuel pump fuse/relay when it has oil pressure, did you try the fuse aswell?

fuse is fine, and the logic that killed that theory for me is it dosent matter how long i crank it on the first turn, it wont start. Even if it was just running, i have to do the 2 step dance all over.
Something changes after the starter has been cranked the first time???

[SweetWagon]

fuse is fine, and the logic that killed that theory for me is it dosent matter how long i crank it on the first turn, it wont start. Even if it was just running, i have to do the 2 step dance all over.
Something changes after the starter has been cranked the first time???

ok, do you mean once you crank it the first time, you have to take the key back to acc or just let it go back to ignition and then try again?? the only thing i can think of is its not getting fuel pressure on the first crank. Does it still do it if you turn the engine off after driving it and start it again a few mins later??

[MyVPIsFasterThanYourVP]

ok, do you mean once you crank it the first time, you have to take the key back to acc or just let it go back to ignition and then try again?? the only thing i can think of is its not getting fuel pressure on the first crank. Does it still do it if you turn the engine off after driving it and start it again a few mins later??

not back to acc, just let it go and turn it again.
yes it seems to do it after its been running, the times i have tried it at least!

[MyVPIsFasterThanYourVP]

oh, and i have tried turning on the ignition, waiting a few seconds till i hear the fuel pump sound change, which i assume is that fuel pressure is at max, then turning the key. but it makes no difference.

[SweetWagon]

not back to acc, just let it go and turn it again.
yes it seems to do it after its been running, the times i have tried it at least!

In this case, im outta idea's. maybe you will just have to put up with it, just one of those things I know with my car I have accidently cranked it in gear a few times, it always has a hard time starting after that... I usually gotta give it some throttle. My friends VP wont start unless you give it some throttle, so im guessing its all fuel related.

[immortality]

this may sound left field but it could be a ECU thing associated with the immobilizer maybe. try swapping the ECU with a known good one out of a mates care etc

[vt1538]

I dont understand why you havent checked for an error code. Something is obviously not functioning & may have logged in the ecm. There are safeguards built into the system that allows the vehicle to still function when certain sensors are no longer working. Whether the ecm needs 1 crank to find the problem & another to run with the revised map I dont know but a check of error codes would confirm this.

[greenfoam]

I'm not 100% sure but I know the map sensor does do a pressure test each time you turn the key, maybe it's not reading fast enough or is half broken?. Anyway I'd be putting down the map sensor as a possibility, even though I doubt the car would run too well if the map sensor had serious issues, depends what your used to I guess but for sure have a look at the errors codes first, ask questions later

[vt1538]

I was thinking more along the line of TPS reading high throttle position & going into clear flood mode. Then on the second try using a rpm based fuel map to start. Either way a code check will verify if any of these are the issue.

[MyVPIsFasterThanYourVP]

I am replacing the unit responsible for the immobilizer this weekend in order to have the working key remotes from the other car, so i will see if indeed that is the case. I am going to look for logged codes then, I have reread the description of how to understand the way the code is flashed enough times now to see if there is something other than code 12!
vt1538, is the problem you are describing going to be affected by the BCM changeover (am told the immobilizer unit to replace is the body control module), or am i going to need to change the main computer with the memcal in it? (which can be done, the other car runs great, starts first time!)
Thank you everyone for all your help, I am not a silly man, I have tried to methodically sort through the permutations and variables and this is driving me nuts, cause the car runs faultlessly other than this 2 key shuffle. I will let you know how i go when i change the BCM.....(I still cant find it!, am told its under the dash above the glovebox, but aside from not being able to remove the back of the glovebox, all i can see above it is the heater blower stuff, i see the main computer fine, and the socket to access the error code mode is hanging down waiting for a paper clip!)

[MyVPIsFasterThanYourVP]

it is fixed, and this is how i did it!
VP Immobilizer swap over from another VP

[stocky]

so what was the problem with it?