starting issues

[99_2door]

99 with 80k miles........right after i bought it a couple months ago, it started having starting issues. every couple days it would randomly not start. it would fire and then shut off immediately. ended up being the passlock sensor and after replacing that everything has been fine. well fast forward to now, the truck has not been started in almost a month because i've been doing a bunch of work to it. the battery was out and when i put it back in, it started up with the problem again. would fire and then shut off. i let it sit over night and the next morning it started and drove great. well the last week it sat while i did some more work and tonight when i went to start it, same thing. wtf is going on!!!! i guess its a possibility that the sensor is bad again but its been fine for months and has only started acting up after sitting. i dont think any work i've done could have messed it up but i'll list it just in case anyone has any ideas....

new fender, grille surround, front and rear bumpers, overhead console, bumper brackets. i did do some wiring (overhead console and new headlights).

anyone have any ideas? has a full tank of gas, newer plugs, filter, etc all from a tune up so i'm leaning back towards the passlock sensor as the symptoms are the same as the original problem. anything i can do to test this short of going to the dealer?

thanks everyone!!!

 

[MetalStorm]

Dude I am in the midst of dealin with the same type of issue on my 99 4 door, 169,000 miles and it is incredibly frustrating. You'll see these threads pop up once in a while and there always seems to be different solutions for each of them. The part that sucks is that the truck will run absolutely fine, its just an intermittent starting problem.

I originally started with fuel delivery to resolve the problem. Fuel pressure is great on mine, changed the fuel filter, and the all popular fuel pressure regulator was changed {kinda a ***** to get to}. Truck ran great, started no problem, then a short time later the problem started again. Mind you it never threw any codes.

Recently did a custom {aka homemade} cold air intake with a K&N, plugs, wires, coil, cap, rotor, SeaFoam, lots of fuel injector cleaner, and 93 octane, and it has started every time since doing that stuff last week.

If, for instance, I have the same problem again I am not sure what direction to go in with this. I have dealt with fuel/air delivery, and ignition components. Again, no codes. If there were that would give me something to work with, but it really is a guessing game.

 

[99_2door]

steve have you replaced the passlock sensor or had anyone suggest it?
when i initially had problems i couldnt figure it out so i took it to the dealer. they determined it to be a passlock sensor and after replacing it everything has been fine up until now. apparently there have been issues with this sensor and i read somewhere that it corrodes and it can be taken apart and cleaned but the dealer fix is just a swap. what i dont get about my situation is about 2 months ago the battery died (it was old) and i put a new one in, everything cool. now i unhook battery for a month while i do some other work and the starting issues are back. there is nothing else i touched on the truck that could have possibly tripped the passlock.




---------- Post added at 09:02 AM ---------- Previous post was at 09:01 AM ----------

*UPDATE* truck started right up this morning no problems. but, the "security" light on the dash was on. never seen that one before.............does this point even more towards the passlock being bad???

 

[MetalStorm]

2 things....

1. what is the passlock sensor and where is it?

2. now that you mention the security dash light, i remember mine did come on once or twice and then it went away. don't remember how i got it to turn off though.

OK I just found a thread on Chevrolet Forum: http://www.chevroletforum.com/forum/showthread.php?t=21877.

I will try to attack this today.

 

[99_2door]

passlock sensor is in the steering column. i believe its part of or inside the ignition switch but i dont know for sure as i took it to the dealer when it got replaced. there seems to be some disagreement about the fix in that link you posted and others i've seen......some guys say the sensor cant go bad? others say it gets burned? i'm thinking about taking it in again (they better warranty this job for as much as they charged!!!!). my girlfriend daily drives this truck and i cant afford to have it torn apart in my driveway while i sort it out.
steve did you notice where the mobile audio guy said he could bypass it for $40? if that wouldnt present any other problems down the road i might check into that because i have been meaning to get a good security system put in the tahoe anyway since i bought it. let me know what you find out today and i'll update you with what the dealer finds.

 

[MetalStorm]

I didn't have a chance to tear my column apart today, but i will definitely keep you informed as to what I find this week. I would have no problem bypassing the security as I have never even had the remote for it.

 

[99_2door]

truck did not make it in to the dealer today. started great all day with no symptoms. pretty hard to bring it in while its starting fine.....you get some funny looks from service advisers!! i also just have the key, no lock/unlock fob, and i've been looking into a quality aftermarket alarm system. as long as i dont have any starting issues in the next few days, i'll prob stop by a few shops and get quotes for a new system and passlock bypass.

btw steve, are you going to do what was suggested in that thread about cleaning the contact points? might be worth pulling it to see if they are indeed burned.

 

[faze]

If you can bypass it...I'd suggest, if it's not too much of a pita, to do it after your next stall, drive it for a week and see if the problem crops up again.

what is the passlock sensor for?

 

[99_2door]

i think its only purpose is when you go to start your car, it reads the resistance off the key and if it doesnt match up with what the computer expects it prevents the engine from running for at least 10 min.

 

[MetalStorm]

I haven't had any starting issues since the work I did that I mentioned earlier. Its been about a week now. The first thing I will do is pull the ignition switch and passlock sensor the next time it happens.