HELP - No cam signal -
Timing chain shouldnt be an issue. I blew the head gasket on the interstate, drove off, car still ran, idled to a parking lot and shut it down. Trailered it home, replaced piston, both heads, gaskets, never touched the cam or chain. Compression I didnt check but see no reason why it wouldnt be good. It wont fire now, but I think it was yesterday I did get it to fire once on starting fluid, It fired for a second and all 8 were firing so mechanically Im thinking its fine. Whatever tells the injectors to fire and the spark I think is messed up.
I have... What all am I looking for? I got signal from crank, tach works, all injectors are firing (so it says) and I didnt see a change in the cam sensor signal though, but i dont know what thats supposed to do. It stayed at 0 but later i seen a 6.
What does the cam sensor control and what does the crank sensor control?
What does the cam sensor control and what does the crank sensor control?
I have... What all am I looking for? I got signal from crank, tach works, all injectors are firing (so it says) and I didnt see a change in the cam sensor signal though, but i dont know what thats supposed to do. It stayed at 0 but later i seen a 6.
What does the cam sensor control and what does the crank sensor control?
What does the cam sensor control and what does the crank sensor control?
Anyway, just thinking out loud here...but you could set the MAF fail hz to "0", and try to start it in SD mode. Not sure if you want to go through all that, but just a thought...
Also seems weird that you're logging 9:1 afr when cranking @ 82* ECT ? Would be interested in seeing the log file.
If you can, log "commanded afr hi-res" as well.
Last edited by salemetro; Jul 29, 2012 at 11:06 PM.
Well, I've heard from others that a bad MAF could cause a no-start situation. I'm not sure how this might be possible, as the PCM is "supposed" to reference the VE table directly after startup (transitioning from the RAF table)?
Anyway, just thinking out loud here...but you could set the MAF fail hz to "0", and try to start it in SD mode. Not sure if you want to go through all that, but just a thought...
Also seems weird that you're logging 9:1 afr when cranking @ 82* ECT ? Would be interested in seeing the log file.
If you can, log "commanded afr hi-res" as well.
Anyway, just thinking out loud here...but you could set the MAF fail hz to "0", and try to start it in SD mode. Not sure if you want to go through all that, but just a thought...
Also seems weird that you're logging 9:1 afr when cranking @ 82* ECT ? Would be interested in seeing the log file.
If you can, log "commanded afr hi-res" as well.
I wont be able to get to it till later today... i'll get a better log.
Also.... is there anything im not logging that I should that would help?
It is a 2 bar SD tune, there is no MAF, I think its set at zero anyway but doesnt reference it. The wideband isnt on the car right now so it defaults to 9:1 on the display. That pic of the log is not a good one, it was more for the codes it has... nothing that seem to be related.
I wont be able to get to it till later today... i'll get a better log.
Also.... is there anything im not logging that I should that would help?
I wont be able to get to it till later today... i'll get a better log.
Also.... is there anything im not logging that I should that would help?
Ahh...I see. Yeah, I saw the 2bar Map, but was unsure of how you were running everything. As far as I can tell, getting the commanded afr logged....along with a working WB might shed some light on what is going on.
Honestly, I was hoping that someone else would have chimed in here by now, because this whole scenario is more than a bit odd.....
Ahh...I see. Yeah, I saw the 2bar Map, but was unsure of how you were running everything. As far as I can tell, getting the commanded afr logged....along with a working WB might shed some light on what is going on.
Honestly, I was hoping that someone else would have chimed in here by now, because this whole scenario is more than a bit odd.....
Honestly, I was hoping that someone else would have chimed in here by now, because this whole scenario is more than a bit odd.....
And the sad thing is its probably something really stupid...lol.
I dont think a WB will help much without it even running or firing.
So far things I checked.
1. Injectors are firing. 12.2 volts at each injector and continuity from signal wire to PCM pin is good.
2. All plugs are firing, changed them out also.
3. Cam sensor wires all have continuity to PCM pins, and swapped cam sensor out also.
4. Crank sensor has continuity to PCM pins and also swapped that out.
5. Grounds are all on engine. <--need to test continuity to PCM yet...hmm.
6. Swapped PCM out. Rewrote entire, also reflashed old one.
7. No codes.
8. Sufficient fuel pressure.
Next step....gasoline and a match...lol.
just as an FYI the engine does not need the cam sensor signal to start. it will typically have a slightly longer cranking time.
Since you had a ground wire problem from the start of this I would go to the pcm connectors with the pcm removed and check resistance to ground on each of the pcm ground wires. (looks like you were headed this way)
as for the spark and fuel I prefer to use a noid light and spark tester. if you are truly getting fuel and spark there would be some sort of fire good or bad
Since you had a ground wire problem from the start of this I would go to the pcm connectors with the pcm removed and check resistance to ground on each of the pcm ground wires. (looks like you were headed this way)
as for the spark and fuel I prefer to use a noid light and spark tester. if you are truly getting fuel and spark there would be some sort of fire good or bad
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Verdad Gallardo just as an FYI the engine does not need the cam sensor signal to start. it will typically have a slightly longer cranking time.
Since you had a ground wire problem from the start of this I would go to the pcm connectors with the pcm removed and check resistance to ground on each of the pcm ground wires. (looks like you were headed this way)
as for the spark and fuel I prefer to use a noid light and spark tester. if you are truly getting fuel and spark there would be some sort of fire good or bad
Since you had a ground wire problem from the start of this I would go to the pcm connectors with the pcm removed and check resistance to ground on each of the pcm ground wires. (looks like you were headed this way)
as for the spark and fuel I prefer to use a noid light and spark tester. if you are truly getting fuel and spark there would be some sort of fire good or bad
The ground issue I had was just the eyelets on the back of the head, when tightening the bolt one must have twisted around and broke. I extended those to a more accesible spot. I dont think im getting fuel... or enough.
If you see a mushroom cloud my way tonight you know what it is....lol.
PM Sent with links to wiring schematics...
I was unable to get entire screen shots with good resolution, so I had to enlarge them. Hope it all helps. Particularly, I tried to enlarge in the areas where the grounds were, being that I'm guessing that this is probably the root of the issues.
I was unable to get entire screen shots with good resolution, so I had to enlarge them. Hope it all helps. Particularly, I tried to enlarge in the areas where the grounds were, being that I'm guessing that this is probably the root of the issues.
I have a list of the pinouts on the pcm. I found all the grounds and tested them at the PCM end, they are all fine. Also again took the crank sensor harness apart and inspected, all fine, all tests fine. The thing turns over hard like it has a lot of timing. So I swapped batteries with another car.....same thing. Nothing.
Tomorrow im ripping off the 160# injectors and putting a set of 60's in to test. You can hear the injectors clicking but I pulled a plug and its dry. ??? I know for sure there is fuel there. The injectors were initially a nightmare to tune so who knows.
Tomorrow im ripping off the 160# injectors and putting a set of 60's in to test. You can hear the injectors clicking but I pulled a plug and its dry. ??? I know for sure there is fuel there. The injectors were initially a nightmare to tune so who knows.
Last edited by pwrtrip75; Jul 30, 2012 at 07:30 PM.
Im thinking its something simple and stupid. Heres what I did tonight.
Car turns over hard, like a lot of timing..
1. Tried battery from my vette... turns over the same.
2. Checked voltage of battery 12.5v
3. Logged cranking voltage. like 9v
4. I put the original battery back in (new Napa gold) 12.5v.
5. I set the vette battery next to the car, hooked up jumper cables from it to the other battery. Then got another set of jumper cables and hooked them to the vette battery to the + terminal bythe fuse block and a ground near it. I also added my battery charger.... let it charge up for a bit.... and logged the ignition voltage while cranking.
Ya ..cranking started out at about 9.6v and after about 15-20 seconds went to 8.8v
Hmmm.. and my battery cables were HOT....hotter than normal. I sense some resistance?? Both these batteries are less than a year old.
I dont know why they dont have 13.2v charged. Broken plated in both? compounded by bad cables.... which my + cable after looking at it is not the best of shape.. inside the loom it must have once hit the header a few times back when it was N/A, its brittle.
And also since I had to buy a set of the billet atomizer injectors... which were a pain to tune because they have no injector data, if the voltage is insufficient.... they are not going to fire worth ****.
My apparatus i had rigged up.... I would think would provide sufficient voltage....supply wise.
Im going to move the battery to the back, put a disconnect on it (to make it legal 8.50 cert) and new cables..... and then go from there and see where I am. Cam sensor is changing now on the log... I know it wasnt before.. who knows. Hopefully it is something as simple as a stupid bad cable. I'll start on this tomorrow and hopefully have it done in a couple days.
Car turns over hard, like a lot of timing..
1. Tried battery from my vette... turns over the same.
2. Checked voltage of battery 12.5v
3. Logged cranking voltage.
like 9v4. I put the original battery back in (new Napa gold) 12.5v.
5. I set the vette battery next to the car, hooked up jumper cables from it to the other battery. Then got another set of jumper cables and hooked them to the vette battery to the + terminal bythe fuse block and a ground near it. I also added my battery charger.... let it charge up for a bit.... and logged the ignition voltage while cranking.
Ya ..cranking started out at about 9.6v and after about 15-20 seconds went to 8.8v
Hmmm.. and my battery cables were HOT....hotter than normal. I sense some resistance?? Both these batteries are less than a year old.
I dont know why they dont have 13.2v charged. Broken plated in both? compounded by bad cables.... which my + cable after looking at it is not the best of shape.. inside the loom it must have once hit the header a few times back when it was N/A, its brittle.
And also since I had to buy a set of the billet atomizer injectors... which were a pain to tune because they have no injector data, if the voltage is insufficient.... they are not going to fire worth ****.
My apparatus i had rigged up.... I would think would provide sufficient voltage....supply wise.
Im going to move the battery to the back, put a disconnect on it (to make it legal 8.50 cert) and new cables..... and then go from there and see where I am. Cam sensor is changing now on the log... I know it wasnt before.. who knows. Hopefully it is something as simple as a stupid bad cable. I'll start on this tomorrow and hopefully have it done in a couple days.
Im going to move the battery to the back, put a disconnect on it (to make it legal 8.50 cert) and new cables..... and then go from there and see where I am. Cam sensor is changing now on the log... I know it wasnt before.. who knows. Hopefully it is something as simple as a stupid bad cable. I'll start on this tomorrow and hopefully have it done in a couple days.
Guess what? Grounding issues....bad ones. Yep, that's right. I finally used a load tester, and found that the battery tested good (in the trunk) @ 1200ca.....but tested 400ca (replace battery) at the distribution point up under the hood. The starter works fine sometimes, but will then rapidly cycle the solenoid other times. I'm going to run a 1/0 cable from the battery negative to one of my subframe connectors since they are welded in, and then one from the front of the subframe connector to the engine block or trans bell housing. Hopefully, this will solve it for me.
Just something to keep in mind, as I thought I did a good job on mine and STILL ended up with ground issues.
BTW....what alternator mount? Looks much cleaner than mine
Well it seems you've tried nearly everything but going back to basics for a sec...check ALL your fuses?
Also, you blew a head gasket? That is pretty rare on these cars and you said you also replaced a piston? WHY? What exactly happened when the car had issues?
I know you said it ran after the gasket issue but it sounds like a mechanical timing problem to me. Does it sound like there is no compression? Assuming you tested everything else correctly, my vote goes toward a jumped or broken timing chain.
Why don't you pull a valve cover and see if your rockers are moving? If they move, that would rule out the broken chain but not if the chain jumped timing.
Also, you blew a head gasket? That is pretty rare on these cars and you said you also replaced a piston? WHY? What exactly happened when the car had issues?
I know you said it ran after the gasket issue but it sounds like a mechanical timing problem to me. Does it sound like there is no compression? Assuming you tested everything else correctly, my vote goes toward a jumped or broken timing chain.
Why don't you pull a valve cover and see if your rockers are moving? If they move, that would rule out the broken chain but not if the chain jumped timing.