Ongoing Nightmare (VATS not the problem)
 

Couldn't find the thread to bring up the old one instead of making this, but anyways, thought I'd give it another shot to see if anyone knew what could be the problem:

Basically, my car will start most the time just fine with no problems. Then, occasionaly, it won't turn over at all. It'll crank and try and turn over, but it just seems like there's zero fuel.

Had the problem diagnosed by multiple people. The first mechanic told my fuel pressure was fine at 55 psi, and that he thought the problem was in the ignition column's housing. Went on here, and everyone was for sure it was VATS. So I took the car to JBA, who removed the VATS...seemed to fix the problem, then two days later, again, my car won't start. It'll start if I continue to crank it over a period of like 10 minutes, but I just feel I'm going to wreck my starter, spark plugs, or whatever with all the cranking. So I took it to CMS, who were busy but nice enough to check to VATS and confirm that JBA had really disabled it.

JBA mentioned that on some Ford's, there's a valve that essentially retains fuel in the motor so that when you have to start the car after it's been urnning, fuel in that valve/hose that is used to basically make it so it doesn't have to get it from the fuel pump. He wasn't sure if the LS1 had the same type of setup, but that he'd do a full diag for 110...

Like I said, most the time, it starts fine. Then other times, it'll just crank and crank and crank with no luck, until if I try it long enough it finally turns over. Any ideas would be greatly appreciated...thanks guys.

Ive had the same issue for the last year, replaced the battery, alternator, powertrain control module, body control module, ignition relay, starter relay, and bypassed the vats system. Everything that I replaced tested or diagnosed as a bad component, last thing I replaced ended up being he starter. I havent had trouble since.

Wow, that sounds horrible...I'm honestly just mind boggled that my starter actually hasn't died yet because of all the times I've had to try and get the car started when it wouldn't. It's honestly gotten to the point where sometimes i don't turn my car off at the gas station because I don't want it to not start and me get stuck there, like I did last week for 40 minutes. :bang:

Ive been there man believe me, had the car towed 4 diff times.

Fuck, that's brutal, I'm sorry to hear that man. The worst part is that half the time I try and explain the problem or show it to someone, it will start up fine for them, then a day later, it does it again when I've got the car home. :mad:

Have you tried checking for spark when the issue comes up? It would be very simple to test for and could narrow the results drastically.

I say fuel pump, check if the pressure drops during cranking. Id change the fuel filter if you haven't ever, its cheap and simple. If u do end up buying a pump get acdelco.

Testing for the problem isnt the issue, its getting it to act up when the testing equipment is available, chevrolet had my car for 2 weeks before it finally acted up with the tech II hooked up to it.

Try cleaning the idle air control valve and see if that helps. It could also be a bad MAF. See if it starts with not having the MAF connected.

I had the same issues and went as far as having the fuel pump swapped. Didn't fix it but while C.J. and I were fiddling with the car at the Pendleton auto hobby shop, we swapped a couple of relays and the freaking car started. I replaced two relays and have never had an issue. The old relays were corroded inside.


Angel

The guy said the fuel pump was fine, and the fuel filter was also changed. Today for example, it didn't start in the morning until the second try. Then when I left school, it didn't start for twenty minutes. Tonight when I went to play basketball at the rec by my house, started before and after just fine...the problem is incredbily frustrating.

To the poster who said how to check spark easily, how can I do that? Also, I'll try and clean the MAF but I heard people can easily fuck it up by doing so..any truth to that?

Thanks for all the help, fellas.

http://www.harborfreight.com/inline-...rce=googlebase

that goes in between your plug and coil and will flash if you are getting spark at that one coil when the coil discharges. Just plug it into some of the easier ones to get to when you are having problems and see what you come up with. You might need help from a friend to watch it or crank the car.

You'll never know until u get it properly diagnosed. I work at a shop that is ASE certified. If u want you can take it to us and we will check it out. No problem is to big man. Pm me if u have more questions

Have fun, intermittent problems suck. And dont jump at the first sign of an error, like I said earlier, everything we replaced on my car diagnosed as bad. The pcm and bcm both had internal error codes.

Don't clean it. They tend to be fragile. Try disconnecting it and see if it starts. You may or may not get an SES light with a P0102 trouble code since you removed the connection to the MAF. If it starts everytime with the MAF disconnected then you know you have a bad sensor. It will idle rough with no MAF.

I would try cleaning the idle air control valve first before doing the MAF thing. The IAC tends to get carbon build up on it. Throttle body celaner will be just fine to clean it.

I've had similar instances like yours, where the problem ended up being a faulty ground connection, either at the back of the cylinder head or at coil pack connector. Both sides are connected to the same grounding point on the back of the head. I'd check there first, since if it was only one side being affected, the engine would still start on one bank.
Coincidentally a faulty power connection will do the same thing.
Go buy a 3 dollar DMM from harbor freight and keep it in the car.
Next time it has the issue, ensure coil pack connecters have sufficient voltage drop on power and ground side. The pcm controls individual cylinder firing by sending a ground path to each coil. It will pulse while cranking. Since the coils work on 12v you can use a test light to probe the connector and look for ground pulses.
If you have a good obd scanner, like a modis, I can also walk you through a few test procedures. Pm me if u need any help.