Thread: 03 Top Swap now starts but shuts off while driving on occasion

Alright guys, i'm at my wits end trying to figure out what's going on. My brother has an 03 GT that we recently top swapped. The car initially started up fine. It did throw a P0300 code. He used the aeroforce gauge to scan and clear it. He drove it for a good 30 minutes and had no issues. He also used the aeroforce gauge to do a case learn which helped get ride of the rough idle after a 30 min drive. The car was running great. On his way home, which is about a 10-15 min drive from me, his car decided to just stall out on the highway. The car has power but it will not crank. I can hear the fuel pump priming but the car will not crank.

Could it be an issue with the security system? By the way the security light is not on.

We have the battery disconnected and will try the security relearn again during the day.

The other thing I am going to do is double check the ground connection under the ICM.

Does anyone have any more ideas?

Here are the list of mods on his car.
Tuned PCM
1.9 rockers
3" catted downpipe
Stock pulley
Aeroforce guage
L36 to L67 wiring harness from wbody store
Injector connectors for the proper connections
L67 harmonic balancer

Existing mods kept
SLP CAI
SLP Cat-Back

First thing you should check for fuel and spark.

Originally Posted by The Guz

it will not crank.

Originally Posted by dsmuts

First thing you should check for fuel and spark.

LOL, Dan..I'm going to double check this with him....I want to keep giggling.

Guz.. when you say "does not crank" you mean the starter is not turning the motor, correct?
Check your connections at the battery, starter and the grounds on the lower front trans stud. Those are the most common things to cause this if they were off. If not, aim for the ignition switch and starter.

I need to stop trying to answer stuff at 430in the morning lol

Well...there are people that say won't crank and they mean won't start. But..yeah..lol

Yeah I completely missed that part I need sleep

Dan...he said it twice.

Originally Posted by BillBoost37

LOL, Dan..I'm going to double check this with him....I want to keep giggling.

Guz.. when you say "does not crank" you mean the starter is not turning the motor, correct?
Check your connections at the battery, starter and the grounds on the lower front trans stud. Those are the most common things to cause this if they were off. If not, aim for the ignition switch and starter.

Yeah by crank I mean it won't start. The key can be turned but the car will not start. It is simlar to the experience I had when the VATS system went out on my 02 Camaro. That is why I am suspecting the anti theft system. But I am open to more ideas to get this thing running again.

Again the car was fine until he was driving home.

The ignition switch was replaced about a month ago. So I know that's good.

The battery terminals are making good contact as the car has power. The interior lights, accessories and exterior lights all turn on.

Originally Posted by BillBoost37

Dan...he said it twice.

I missed it twice lol

Tried the security relearn thing again. Still nothing.

Checked the ground connections and they are good.

Battery connections are good and tight.

Swapped the stock PCM and it didn't start.

The fuel pump primes and the engine does its thing when the fuel system primes.

Checked all the fuses and they are all good.

We did notice that when turning the key to the on position the DIC and radio go out until the key is turned back.

so you turn the key to crank it and you get nothing? not even a click?

could be the starter went bad, try beating it with a hammer, a few good shots, while someone else turns the key can beat them back to life. temp fix.

if your getting a click this will work sometimes. its a 50/50 shot either way really.

have you also tried to turn the engine over by hand, to see if it locked up? hope not.....

Checked all the IGN fuses?

Originally Posted by scottydoggs

so you turn the key to crank it and you get nothing? not even a click?

could be the starter went bad, try beating it with a hammer, a few good shots, while someone else turns the key can beat them back to life. temp fix.

if your getting a click this will work sometimes. its a 50/50 shot either way really.

have you also tried to turn the engine over by hand, to see if it locked up? hope not.....

I'll give this a shot to try and see if it starts. We could hear a click in the fuse area in the glove box. But that's about it. We also have not tried turning it over by hand.

Checked all the IGN fuses?

They are all good.

Ok.. first off... read up on the security system before blaming it. Knowledge is key to diagnostics. Even my neighbors 02 will crank it's life away if the security system is pissed. Our cars kill fuel when security kicks in..... so your syptoms would be start on fuel pump prime and die in 2-5 seconds. Turning the key fully back to off then start will do this over and over.

If you have no engine cranking (not to be confused with engine starting), there is one of a few issues. Starter, ignition switch (and I'll send you a dead rotting fish carcass in the mail if you think a new part can't go bad in a month...please pm me your addy), or battery cable connections. Key here is..it stalled on the drive. That's odd. Definately try turning it by hand. Maybe a gasket let go etc and you hydrolocked.

Security info... honestly I've been able to diagnose a lot of stuff based on reading up on it. It's good to know how it acts.
Fish...just because..if you are gullible enough to believe new parts don't go bad, you'd probably send me your address.

Check the crank sensor and the wiring going it to it. If the wiring wasn't routed right it could've rubbed on the belts or pulley and cut through the wire.

Originally Posted by Swiggles

Check the crank sensor and the wiring going it to it. If the wiring wasn't routed right it could've rubbed on the belts or pulley and cut through the wire.

happened to me, too. car died while driving. wiggled the wiring harness and the car started. got home and taped everything back up and made sure it was routed nicely and it was good to go.

Originally Posted by Swiggles

Check the crank sensor and the wiring going it to it. If the wiring wasn't routed right it could've rubbed on the belts or pulley and cut through the wire.

Took a look at it and sure enough, one of the wires was sliced throogh. Fixed that and still nothing. Definitely a good catch.

could be the starter went bad, try beating it with a hammer, a few good shots, while someone else turns the key can beat them back to life. temp fix.

have you also tried to turn the engine over by hand, to see if it locked up? hope not.....

Tried the starter and nothing. Turned the engine by hand and that's fine.

Still looking for the issue.

have you tried to jump the starter with a screw driver yet?