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iTrader: (6)

Alright guys, I've researched the hell out of this problem and I can't seem to find anything that fits my situation specifically.

A little background: 350 swap, LT1 injectors, chipped ECM for bigger injectors, new fuel pump, new fuel sending unit, new fuel pump relay, new FPR.

The car starts completely fine on cold starts, but after I let the engine warm up and shut the car off, I go to restart it and it just cranks. Will eventually start if I continue to hold it and then SOMETIMES it will throw a CEL. Every time I've checked the CEL it comes back with code 54. The research I've done says it could be a bad ECM or something wrong with the charging system. The battery is a couple years old but sometimes if I let the car sit for a while it drains quite a bit. I will also say that I have no idea how old the alternator is and sometimes when I'm sitting a stop light with the turn signals on, the signals blink pretty slow. I've thought about replacing the alternator but I haven't gotten around to it yet.

I'm at a loss with this problem. I've thrown some parts at it thinking that those parts would fix my problem and I still end up with it. I'm starting to lean towards the ECM being bad but I'm not sure.

Any help will be GREATLY appreciated. I've been dealing with this problem for a couple years and I'm finally getting fed up with it. My biggest problem is I can't seem to remember for the life of me when I started having this issue.

Thanks in advance. If there is anything else that I could answer that may help diagnose this, please ask and I'll be more than happy to answer.

CombustoBird89

Your system sounds like it may have a parasitic drain somewhere...have you checked wiring or did a voltage drop test yet? Wiring can look good cool, then act up when hot.
Also i remember reading here about a diode in the alternator that can play games with this situation. Has your battery been checked?
Also look at: icm...coil...vats...

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iTrader: (6)

Haven't really checked into the wiring all to much, will have to call a buddy in for assistance with that, I'm not big on wiring.

I haven't had my charging system checked recently, which is something that is next on my list of things to do.

ICM was checked about 2 years ago and tested good, will probably get that checked again. Coil is about 2 years old, but still is on my list as a possibility. And VATS is out of the question because my car isn't equipped with it.

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iTrader: (6)

Alright guys, ran the car down to O'Reilly's tonight after work to have the alternator and battery tested. Alternator came back at 34 amps at idle, which to me, is way too low. Battery came back with 440cca and it's a 700cca battery. My O'Reilly's store didn't have an alternator so they're bringing it in from another store, picking that up tomorrow night. Also going to run my battery into Advance tomorrow night and swap it out for a new one. It's only 4 years old so I'm hoping it's still under warranty and I can at least get a new one at a prorated price.

I'm seriously hoping this will fix my issue. Should have the new alternator and battery installed tomorrow night so I will keep everyone posted.

If my issue still persists, up next is checking the ECM and the wiring for the fuel pump.

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iTrader: (6)

Even though there doesn't seem to be any interest in this matter anymore, I'll still update in case someone else is having this problem and stumbles upon this thread from searching.

Installed new alternator and battery the other night. On initial start up I noticed right away that the fuel pump sounded a lot stronger. Started perfect and let it run until engine was warm and shut it off. I started it back up after about 5 minutes and it started right up. Drove it to work yesterday and after I shut it down in the garage I let it sit for about 5-10 minutes. Went to restart and it fired right up again. Tried it a couple more times before I finally went inside and never had the problem.

So I'm hoping this good luck continues and a weak charging system was the culprit.

Mr Froman

Code 54 is a fuel pump code. Low voltage.


So here is what I would do: Drive. Drive for a while. Shut vehicle off. Check battery voltage. If the battery voltage is less than 12 volts, well you may have a bad battery or a charging issue. If you battery is okay, check alternator output. 35 amps at idle is plenty.

If you alternator and battery check out fine, check voltage to your fuel pump relay. If you need a wiring diagram to see what is power and what is ground just let me know. If voltage TO the relay is fine, replace the relay. They are fairly cheap.