streetassasin

iTrader: (30)

I went to leave work this morning and the car wouldnt start. It has solid fuel press. and turns over but wont start. If I kept cranking it, it would fire maybe once or twice but thats it. I checked the grounds under the hood and they are solid and no blown fuses. Any ideas guys?

LS1_Fonzie

iTrader: (4)

I had this problem a couple of times and each time it ended up being a bad relay. The first one that went bad was the starter relay located in one of the fuse boxes under the hood. You can test it by swapping it with one of the fan relays. The 2nd time this problem occurred it was the fuel pump relay also located in one of the boxes under the hood. You can test that one by swapping it with the A/C relay, I believe they are both the same. Best of luck, hope this helps.

streetassasin

iTrader: (30)

If it was the starter relay it wouldnt turn over though right? It turns over but just wont fire up. And its getting fuel, I have a gauge on the rail and it shows good pressure when I try to start it.

bad_408_vert

iTrader: (6)

Check for spark at all wires.
If you aren't getting spark, check Coil packs.

If there's no spark at a particular coil, coil might be bad.

If there no spark in any of coils, might be your ICM(under the coils, it has tendency to fail due to overheating since its right above the head).

When the car eventually started, what were the symptoms?
Did the motor cut out eventually? Did the rpms jump a little?

streetassasin

iTrader: (30)

ICM? The car never started, its still in my work parking lot

LS1_Fonzie

iTrader: (4)

My car would still crank over but wouldn't start. I would hold the key in the start position and it would just crank over and over but never fire up. You could check the ignition relay as well, sits right next to the starter relay. I ended up replacing both relays since they were both old. After I replaced them it fired up fine on the first try and hasn't failed me since. That was a little over 2 years ago.

nemss1

same problem here. car has been sitting for awhile and im assuming bad gas. what else could go wrong to cause it not to fire from sitting? gunked plugs also maybe?

bad_408_vert

iTrader: (6)

ICM is Ignition Control Module.

From my experience, it seems like a spark issue.

Its happened to me twice within last 3 years and exact symptoms.

Left the car for few hours and wouldn't start, just cranks.

You should always start from smaller things like relays n other things mentioned, but this sounds very similar to issue i had.

You can have the ICM tested at autozone & other parts stores just like an alternator or the battery.

streetassasin

iTrader: (30)

I feel like a noob asking this but where is the icm exactly and what does it look like?

bad_408_vert

iTrader: (6)

ICM is what the coil packs sit on basically.

Its a rectangle looking thing under the coils.

It shouldn't take more than 15 minutes if you have proper tools.

To get to it, you have to take off the coils and on the back of it a plug goes with about 14 wires that has a bolt on it.

Take of the bolt and ICM is free to come out.

98pontiac

try spraying a little bit of starting fluid in the throttle body and see if it starts.. I was just wondering how you checked the fuel pressure, and what was the psi?

nemss1

oh.....and car does NOT start on starting fluid either. forgot to add that. fuel pump primes, pressure at rails. havent checked plugs yet. keep in mind my car was sitting for several months and did start a couple months ago and ran very rough. thats why i was assuming bad gas or gunked over plugs

streetassasin

iTrader: (30)

I have a fuel press. gauge on the rail,it has around 60 psi. I just tried swapping the starter and ignition relays with the fan relay but nothing. Which side of the motor is the icm on and how much are they?

thanks for the help so far

bad_408_vert

iTrader: (6)

It's on top of the driver side head, under the 4 coilpacks.

streetassasin

iTrader: (30)

Any more ideas? I finally got the car towed how and its not throwing any codes, Im leaning toward the cam sensor or the crank sensor, I have a gut feeling its the crank

Lucifer 00

iTrader: (2)

Pull a plug wire and have an assistant crank over the car while you watch for spark output. No output? Replace the crank sensor, its on the passenger side behind the starter. The ignition control module that bad 408 is talking about is non existing on ls1 engines, those are found on the v6 models ie. 3.8, 3.4, 3.1, etc. Be sure to hold the plug way close to a ground source, like a head bolt, the tip of the spark plug etc. Keep your fingers away!

Tuffguy610

iTrader: (2)

Hey Lucifer,
My car is doing something similar, except mine is intermittent. If I turn the key back and forth enough, it'll eventually start. My car is a weekend cruiser, but has seen less than 500 miles of road in the past 3 months. Although today I took it to work and she fired right up, but it is warmer outside than last week when the problem got really bad. They keep telling me that the crank sensor is going out, and it makes sense. My sister's chrysler did the same thing last year, I popped a new crank sensor in it and it ran like a top right after. Hope you fix yours, let me know how you make out.

Lucifer 00

iTrader: (2)

Hey Tuff,
Give me some more info, The moving of the key suggests a bad switch, relay, fuel pump etc. Try to duplicate the problem and find out whats missing. Start with the basics, fuel, air, spark. It sounds like a fuel pump to start off with because by rocking the key on and off your pulsing voltage to the pump and that will cause it to jump back into action.

Streetasassain,
Get your car fixed???

Lucifer 00

iTrader: (2)

Streetasassain,
BTW be sure to use an OEM delco crank sensor, aftermarket sensors are junk.

Tuffguy610

iTrader: (2)

Lucifer,
My car doesn't have a fuel issue. I know this because when I turn the key to the "on" position I hear the fuel pump prime every time. I don't think its switch related, I might have made it sound that way. What I'll do is try to crank it, and let off of the key after 3 seconds because I dont want to kill my starter. Then I'll turn the key back to the "off" position, then try and start again, repeating this procedure until she fires. I really think its a spark issue, but can't tell because I don't have a second person around to crank while I test the plugs for a spark. I drove it the other day and it ran great, fired up immediately and everything, but it was the first day that it was 10 degrees above freezing. I have my money on the crankshaft sensor, but I'll wait it out seeing as this car doesn't see much use.