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Car wont start - please help - info within

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Old 10-02-2008, 08:35 AM
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Default Car wont start - please help - info within

Not sure if this is the right section, but i know its gets a LOT of attention and i need help very fast. I am supposed to leave in the morning for a 3 day trip, and want to drive the car.

Hey guys,

At 11:30 PM last night, my TA officially became non-running.

Here is the background info and details of my saga up untill this point.

The car i purchased had been sitting for 8 months prior to me buying it. The car is also high mileage (149k now)

When i first got the car i noticed it had a little bit of a hesitation from about 3k till about 5k or so, but would clear up once it got to 5k or so. It wasn't a miss or a studder, just as if you had backed your foot off the gas pedal about 1/3 of the way. The SES Light was on. I figured it was a combination of this miss, and the fact the car has gutted cats with o2 sims (sometimes sit off SES still)

I started out by putting a can of sea foam in the gas. I ran this tank to near empty. I then changed the fuel filter.

The car still had the hesitation. Also note... the car was fine if you just putt'd it around. Idle to about 3k it was fine, and if thats all i was doing, sometimes the SES light would actually go off after driving it this way a couple times in a row.

Next step was to hook my laptop up to it. EFI Live tells me the codes it is throwing is "Sensor 1 Bank 1 o2 sensor low voltage" and "Sensor 1 bank 2 o2 sensor low voltage"

After talking to a couple friends on the phone, we determined it was a pretty good chance this was the culprit.

Last night i replaces both o2 sensors with new ones. In addition to that, i also put new plugs and MSD wires on it, to rule out any sort of miss associated with that. I also swapped out the MAF for the "Known to be good one" off my TA (I double checked they were the exact same, and interchangable, on LS1 tech before swappig my 99 one on a 98 car). I also removed the EGR off the car, because its nothing but trouble on those cars.

Car starts right up after all this, but the SES light is still on. I drive it down the road, and the hesitation is a bit "smoother" but still doing the same thing. I figure the plugs and wires helped a little, but the underlieing problem was still definitely present.

I drive it down to my house from my grandpas, go in for a few min, etc, then go back outside to run my friend back home. I notice the car starts a tiny bit hard (normally its started before you can even turn it over, i think i heard it turn over once or twice before it fired). Kinda wierd.. but whatever... it still seems to run fine once started.

We stop at napa to grab a couple things (we both have keys, and he still works there )

We go to leave napa, and the car wont start. It turns over and turns over, nothing, not even an attempt to start.

My buddy gets out and ***** around with some stuff while i crank over. He determines it has spark. We then spray some carb cleaner down the intake, but it still wont even begin to try to start. We hear to see if the fuel pump is kicking on, it is we can hear it.

So right now im kinda at a loss and want to avoid as much trial and error as possible (this bitch needs to be on the road this time tomorrow).

Things i have in mind: Crank Sensor, Cam Sensor, Fuel Pump, Injectors.

At lunch today my buddy is gona borrow the fuel pressure tester from his work and hook it up to the schrader valve. We are also going to swap out the injectors tonight to see if that fixes it. If that doesn't fix it, im taking the crank sensor out of my Z28 and throwing it in there to see if thats the problem. The cam sensor would be a last resort because it requires pretty much removing the intake, but i will also try that i guess.

I dont think its anything mechanical within the motor. The car purrs like a kitten and holds great oil pressure.

Any and all help is appreciated. Thanks

Zack
Old 10-02-2008, 10:59 AM
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well since you replaced the fuel filter, new plugs and wires and got a new MAF i would have to say that your motor is starving for fuel.

So i too am going to say fuel pump. Byt why after you changed both 02 sensors your getting an SES light i have no idea.

What exhasut do you have on the car? Did you change the front 2 or the rear 2 02s?

I dont think it is the crank sensor or the injectors you ran a can of seafoam so that would do a lot of cleaing. Once you get the car running again, take about 10oz of seafaom and run it thru the motor. That will clean a bunch of junk out. Let it sit maybe 45 mins. You know how to do that?
Old 10-02-2008, 11:24 AM
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Originally Posted by TORCHD 02 TA
well since you replaced the fuel filter, new plugs and wires and got a new MAF i would have to say that your motor is starving for fuel.

So i too am going to say fuel pump. Byt why after you changed both 02 sensors your getting an SES light i have no idea.

What exhasut do you have on the car? Did you change the front 2 or the rear 2 02s?

I dont think it is the crank sensor or the injectors you ran a can of seafoam so that would do a lot of cleaing. Once you get the car running again, take about 10oz of seafaom and run it thru the motor. That will clean a bunch of junk out. Let it sit maybe 45 mins. You know how to do that?
I just replaced the front two o2's. The rear ones have sims on them (car has gutted cats from previous owned)

I ran seafoam in the fuel system, and also poured half a can in the oil before i changed it and drove it a couple hundred miles.

The car is now running again. It started up fine this morning when my friend went to start troubleshooting it. I just drove it and it starts ok, but just feels weak all over kinda.
Old 10-02-2008, 11:44 AM
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Originally Posted by z28mccrory
I just replaced the front two o2's. The rear ones have sims on them (car has gutted cats from previous owned)

I ran seafoam in the fuel system, and also poured half a can in the oil before i changed it and drove it a couple hundred miles.

The car is now running again. It started up fine this morning when my friend went to start troubleshooting it. I just drove it and it starts ok, but just feels weak all over kinda.
I wonder b/c you have the SES light b/c of the rear 02s your car is running ins SAFE MODE.........

Try to change the fuel pump.. other than that i am ouuta ideas. Cam sensor either the car starts or it doesnt
Old 10-02-2008, 11:50 AM
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How would i go about checking if its put its self into safe mode?
Old 10-02-2008, 11:51 AM
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scanner and check the codes
Old 10-02-2008, 11:58 AM
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Originally Posted by twitchtwice
scanner and check the codes
Old 10-02-2008, 12:30 PM
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Originally Posted by TORCHD 02 TA
So if EFI Live scan tool doesn't pick it up, then i can cross that off the list?
Old 10-02-2008, 01:15 PM
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Originally Posted by z28mccrory
So if EFI Live scan tool doesn't pick it up, then i can cross that off the list?
well no.. you have a SES light on for a reason....

did you scan your car yet?
Old 10-02-2008, 01:24 PM
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Originally Posted by TORCHD 02 TA
well no.. you have a SES light on for a reason....

did you scan your car yet?
Not since the o2 change... just here at working biting my nails trying to figure out all the different reasons.
Old 10-02-2008, 03:49 PM
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Originally Posted by z28mccrory
Not since the o2 change... just here at working biting my nails trying to figure out all the different reasons.
yeah man i am at a loss.. i dont think that you will be driving your car tomorrow
Old 10-02-2008, 04:41 PM
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check your fuel pressure...im new to ls1's but my 5.0's fuel presure regulator was going bad and it acted like that...
Old 10-03-2008, 12:24 AM
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did you check the fuse for the bank 1 o2 sensors? could just be a blown fuse, especially since both sensors have the low voltage code.




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