Wont start again

Thanks!!


I thought IAC, I have been suspecting it to be going bad cause I have a funny idle sometimes but yesterday I swear it was like 60 something outside and its not just a cold start issue its just a no start issue flat out.


I read someone on another site saying it took 15-20 seconds to start his car when it was having a what seemed to be a similar problem but if I try that I get around 7 maybe 8 seconds:rolleyes: :rolleyes: :rolleyes: and it kind of gets rough but shows no sign of turning over and last thing I wanna do is drain my new battery and not have a way to charge it directly from the car since it wont start. I got sick of taking it in to get a charge when the fuse went for the fuel pump issue I had.

All this after my smart assed comment about how reliable the LS is:Bang :lol:

It f*cking sucks not having both cars when you need them I gotta get up 3 hours in advance regardless to get the kids ready for the sitter and now I gotta get up a extra 3 hours cause I need to wait for the damn wife to get ready, take her to work, take the kids to the sitters house and then drive all the way to work myself.
 
here is what I believe is the Cam Position Sensor (CMP):

CMP connector.jpg


CMP sensor.jpg
 
Oops, I just sent you a PM quick.

Ok now I get it. That is just a connector in the second pick. Quick, you know lots would you suspect it to be the "cmp" since 97stscaddy said it wasn't to likely to be the issue but maybe a possibility still?
 
I have not seen a CMP cause this issue - but certainly could...

The steps in the 'normal crank - no start' troubleshooting are:
- CHECK PASSIVE ANTI-THEFT SYSTEM (SECURILOCK)
- CHECK VREF VOLTAGE TO THROTTLE POSITION (TP) SENSOR
- CHECK FLASH EPROM POWER SUPPLY (FEPS) CIRCUIT FOR SHORT TO POWER IN HARNESS
- CHECK RPM IN THE PCM
- CHECK FUEL PRESSURE
- CHECK FUEL PRESSURE LEAKDOWN
- CHECK FUEL INJECTORS FOR VPWR
- CHECK FUEL INJECTORS ABILITY TO DELIVER FUEL
- CHECK INJECTOR SIGNAL FROM NGV MODULE
- CHECK PCM DRIVER TO COILS
- COMPLETE REAR ELECTRONICS MODULE SELF-TEST TO VERIFY IFS SWITCH INPUT TO
REM (REM PIN J3-8)
- CHECK IFS SWITCH INPUT CIRCUIT TO REM (REM PIN J3-8)

if it was the IAC - it will either be closed (and starve the engine of air) or open (and the engine can't hold a vacuum). But it usually starts - then stalls. you could remove the IAC and block off the IAC inlet/outlet on the throttle body. then try to start it with the throttle plate partly open....
 
Ok, I got all that stuff in the PDF you emailed me, and thanks again.

So far I cant find my voltage tester. I know my pump is at least trying to send fuel.

But, exactly how do I check the securilock thing? I mean if its on the dash what would I look for considering all kinds of lights come on till the car cranks over?

Man I might have to bite the bullet and take it to the dealership, I dont know where half of those things even are.


The only good lead I have is that I messed with my filter and removed the entire MAF housing unit along with my filter and then I removed my filter to clean it. That was the last thing I did before the car would not run but it looks good in appearance and is fairly new unless they shafted me and sent me a cleaned up used one.
 
Update*


robert_stack.jpg

:p

Now I had some one come over and give me a hand with cranking it while I was messing with hoses and what not and I found that there is not much of a vacuum but if I remove the IAC hose and clog it up the car acts like it wants to kick over.
 
"f it was the IAC - it will either be closed (and starve the engine of air) or open (and the engine can't hold a vacuum). But it usually starts - then stalls. you could remove the IAC and block off the IAC inlet/outlet on the throttle body. then try to start it with the throttle plate partly open...."

Do I take this as a way I could verify if the IAC work or not? If that is then I will be damn!
__________________
 
What about the sensor on the IAC? Would I want to leave that connected?
 
the IAC is simply a valve to allow air to sneak from the intake around a closed throttle plate into the manifold. so at idle - the PCM watches the rpm an continually adjusts the IAC valve to allow more or less air to bypass the throttle plate to peek at the 'target' idle rpm.

you need to leave the wiring connected to the IAC - or the PCM will throw a error.
 
Dankar said:
"f it was the IAC - it will either be closed (and starve the engine of air) or open (and the engine can't hold a vacuum). But it usually starts - then stalls. you could remove the IAC and block off the IAC inlet/outlet on the throttle body. then try to start it with the throttle plate partly open...."

Do I take this as a way I could verify if the IAC work or not? If that is then I will be damn!
__________________
Click to expand...

Any good suggestions on how to do that without sucking something in like I know I will?:shifty:


Thanks Quick, your the man as always.
 
Yeah, don't put your fingers in it... :p


Do I take this as a way I could verify if the IAC work or not? If that is then I will be damn!
Click to expand...

The IAC is normally wide open during starting and should adjust as soon as the engine starts running to control idle speed.
 
the LS IAC is a little more complex than the average one (go figure).

normally - the IAC simply stradles two holes in the intake run - one before the throlle plate, and one after.

on the LS - the IAC is fed from a large tube coming off the intake (well in front of the throttle plate) and then feeds both the intake manifold and the air assist injector rail with seperate tubes......

just to keep you on your toes..
 
Yeah I took mine off and cleaned it once. Haven't ever seen one like that before, but it still works pretty much the same way.
 
Tell me about it. I have been looking it up as far as trouble shooting and cleaning and cant find a specific LS one. So, I just figured I would use one in general as a quick reference. Right:rolleyes: !


Ok so now I have the IAC off but no one is around to try the starting it for me while I block the hose and the input,

Im still not understanding this concept, shouldn't I have to block the back of the IAC also since the TB would be pulling in air and air would pass the now disconnected IAC missing the air meter meaning I would get un-metered air?


I may just be misunderstanding.


The valve inside the IAC is kind of stiff like it may be sticking in some way. But, it does not close all the way, its like there is a spring that lets it open the slightest bit but it is still kind of on the sticky sluggish side.


EDIT: I was doing a search and I found something I totally forgot about. It was a funny noise that 97stscaddy said was just the air passing by the throttle plate but I insisted on it being a vacuum leak. Im wondering........???
 
Bare in mind Im no mechanic but I thought about something. Could I have a huge vacuum leak? Im thinking maybe just maybe by holding my hand over the hole on the IAC it was building up some pressure so when I let off it sucked in just enough air with force to almost wanna kick over? I did feel little suction when I had my hand over the hole.
 
Ahhh third post in a row in my own thread! Ahhh, ok now how about timing chain? I heard a funny ticking noise that was never solved and I got all sorts of possibilities. If my timing chain was busted the car wouldn't start but would it even crank? How about the fact it almost acted like it wanted to start when I had my hand over that hole? If the timing chain was broken would it have even done that?
 
Give it a rest brother! :P


Timing chain? Probably not. You would notice a pretty distinct broken /clanking sound, and it would seem like it was cranking faster from there being less resistance.
Vacuum leak would be possible, but it would usually still start first, then die right away. There would have to be a leak the size of your MAF sensor to keep it from starting. Even if you disconnect the brake booster hose (which is a 3/8" id hose) it will still start, but then it will run like scheiss for a few seconds then die.


Ok so now I have the IAC off but no one is around to try the starting it for me while I block the hose and the input,
Click to expand...
Haven't you ever heard of duct tape?
 
I cant give it a rest! I need my car:eek: :D

Im thinking maybe a large hose is straight up disconnected or something as far as vacuum.

And yes I heard of duct tape:rolleyes: :p , but that last thing I need is to start the car and suck it in some how or another. Im just paranoid, its just my luck that the cold bare metal wont hold it enough and suck it in;) . Trust me it really is:(

But what about the un-metered air with the IAC off?
 
But what about the un-metered air with the IAC off?
Click to expand...

Tape over that hole too!

Just wrap the tape the whole way around the top of the throttle body and it wont get sucked in. Or you could use something else that's harder, like an old tupperware lid cut up into peices, and just use the tape to hold that over the hole.
 
I assume if it's a security thing, that light on top of the dashboard at the base of the windshield would blink funny- not sure of the sequence though. Perhaps try a different key?
when i pop my plastic intake tube off, its always 6 connections i have to put back on. 2 hose clamps for throttle body and filter box, 2 snap in hoses, and 2 plugs, the maf and another little sensor. If its not any of that, and nothing else was changed, its probably not a vacuum leak. my car will not start at all without all this crap in place.
do you know for sure your fuel pump is working? it may make noise like its priming, but perhaps its not delivering fuel. This could be why you blew a fuse before, because it got overloaded.
Also, how much does your fuel gage read? Perhaps your driver's side pump is not pumping over to the passenger side. The fuel reading comes from the drivers side, but delivery to the engine is passenger.
Test for fuel delivery by putting a fuel pressure gage on the schrader valve on the fuel rail (driver's side of engine). Make sure you're automatic fuel pump shutoff switch is working properly and that the button is pushed down (on the drivers side floor right by where your left ankle would be). Throw a test light on the injector leads; if you heard ticking, it is probably them working properly.
Next is spark- you can pull the spark plugs and coils and test this easy enough.
if you still have not found anything wrong at that point then start worrying about sensors.
 
Im positive its spark or compression loss. Im scared to spray some starter fluid in cause I heard bad stuff about forcing engines over with it in my situation so I dashed some gas into the TB, just a splash and I got nothing.


But again on the other hand its as if Im not getting enough vacuum cause like I said, I hold my hand over that hole, crank and crank, let go the slightest from the hole and it almost turns over.


Unless my schrader valves cap is different I still cant freakin find it either!
 
You're not going to get vacuum until the car runs.

You need three things for a car to start - air, fuel and spark.
 
I feel some suction from the IAC like I said so does that mean I still have some compression? Im getting worried its some leak down and I some how did something to the motor. If it honestly was no spark or no fuel it would not want to turn over if I took my hand off the IAC while cranking it like it does. Unless its not turning it over and its something else but it acts just like it wants to start for a second.


See Im in a predicament, I am parked n a incline with the front facing the curb and Im damn close to the curb so I cant even jack the car up!:Bang


That and I got a slow leak in one of my winter wheels. My cars falling apart:lol:


What ever, It will work out sooner or later but I am also moving in less than two weeks so hopefully I get it running by then:rolleyes:
 
I feel some suction from the IAC like I said so does that mean I still have some compression?
Click to expand...

It means you have suction, which should also mean that there is compression. But to ease your mind, run a compression test, it can't hurt.

Then while you have the plugs out, crank it over a few times and see if you're getting fuel (it will spray out of the cylinders). Then put the plugs back and leave out a few coils in a place where the springs are almost touching something metal and give it a few cranks to see if you get any spark.
 
IAC valve

Hey, I noted in your previous message that it tried to start when you messed with the IAC. These valve poop out, they get carboned up or the solenoid dies out. When mine died, the car would start sometimes or just crank, finally it would just crank. So I replaced it, started right up and works great. Let us know what you find.
 
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