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Discussion Starter #1
i got my LET rebuilt the other night and got it back in the astra the day. after we got it all in and ready to fire i gave it a good few minutes cranking to get some oil round the engine. oil light now goes out straight away.

but when we came to start it we hit a snag :rolleyes:

basically when you turn it over it starts but dies straight away every time

a list of things we have tried tonight

fuel pressure - 3 bar constant
spark - sparks excellent
ecu light - comes on and goes out straight away while cranking and comes back on again when it cuts out
compression test - 170 across the board
fuel lines - both on the rail the correct way
all boost hoses and pipes etc are all on and secure

we also had the jump leads on from another car just to make sure it wasnt dropping voltage.

so we are gettin ecu power, compression, fuel and a spark yet the ****er wont keep running :mad:

has anyone got any experience of this or any idea why its doin it? cause we've tried everything we know that could cause it.

we have a full other running LET engine that we can swap sensors etc from if anyone suggests any that could be causing it - although we arent gettin a fault light up...

cheers

rodgerq
 

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Does it die if you put your foot on the accelerator?
how much petrol have you got in the tank - that got me a couple of weeks ago
Can you try unplugging the AFM?
 

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You've got the ignition barrel wired up correctly?
ie. with the key in position II, after starting, are the correct wires still getting power to keep whatever should be, running.
 

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Discussion Starter #4
i put a fiver worth in but the digi gauge is showing full and its gettin pressure so its defo not that.

it still dies even if you put the foot down but will rev up first for the second or so it runs then does the same...dies lol

i havent tried unplugging the AFM - what would this test?

rodgerq
 

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Discussion Starter #5
the_fbi said:
You've got the ignition barrel wired up correctly?
ie. with the key in position II, after starting, are the correct wires still getting power to keep whatever should be, running.
yeah on cranking the ecu gets 12v. i even held the key round the the ctranking position after it started to make sure but it still died

rodgerq
 

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Sounds like cam timing is out

check the valve & piston timing (cam timing) :beer:
 

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Discussion Starter #10
timing has been checked and is spot on.

crank sensor is a brand spanker. air flow meter is plugged in.

i will check tomorrow for leaks and ill check the icv aswell.

keep the suggestions coming though folks :beer:

cheers

rodgerq
 

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Chipped or standard ecu m8, i had this problem and its down to ecu on mine, sometimes it will start and just cut out, if i unplug the ecu and plug it back in it works fine for a few days then goes pear shaped again.
 

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leave the battery unplugged overnight and try is the next day. I had this with the V6 swap and know of someone else who had the same problem. the theory was the engine was flooded when initially cranking, so needed to be left to dry out. Resetting the ecu is never a bad idea either.
Next morning in both cases, the car started and ran first turn of the key.
 

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For it to stop running it has to be losing fuel or spark really. If the icv was wide open it will still run with throttle,ive ran mine with no icv it just need rigorous pumping of the throttle to keep it going.
Fuel pressure is good but what about cold start enrichment? Its sound like a carbed motor when the choke isnt pulled out. Fires then dies on each crank yeah??
 

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Had this problem with mine for a couple of months now, and after a lot of part changing, and icv cleaning it was still doing it,
havent done anything since and it seems the little elves have been round in the middle of the night and done something because its miraclousy repaired itself and now runs fine,

On a more serious note, what about swapping the loom with your other one just to rule that out, as their a bitch to detect.
 

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Cam or crank sensor, maybe both. Sounds like it starts, then get a false reading from a sensor and the ecu cuts the fuel!
 

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had this with my LET would start and about 3 seconds later would just cut out.

checked and changed loads of things and was at the point in giving up lmao

took my air mass meter out and swapped it, fired up and ran perfect :D
 

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Discussion Starter #17
fuel and spark have been checked and are fine - i put a lead and plug against the dizzy and fired it up and it sparked fine even after the engien cut out and in the second or two it takes to stop turning the spark was still there - thsi also indicates that the loom is losing power.

plugs are always wet when i remove them to. i tried starting it with the cts unplugged but it made no difference.

i will try the air flow meter from the nova today.

the ecu is standard. i have another i can put in and check its not that so ill do that aswell.

cheers

rodgerq
 

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Tried removing all the plugs, disconnecting the injectors and cranking it over a few times to clear the bores out?

Does it bog down then cut out?
 

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Discussion Starter #20
andy, i think its me thats cursed it mate not Simon.

astra - it doesnt bog down, it just fires up then straight away it dies.

rodgerq
 
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