My wife's car died several times on her in one 10 mile trip home. It didn't light up the check engine light, and there were no codes. I went on. No fuel pressure, so I changed the pump. Still no pressure. I changed the filter while I was there. I figured I would continue checking other things like spark. No spark, so I changed the crank position sensor. Still no spark. The relay would make noise so I swapped the A/C and fuel pump relays. No change. I put a new relay in. No change. There is also a strange noise coming from the top of the engine where the fuel lines meet the engine. While I was ordering parts from GM Parts Direct, I went ahead and got a new ECM or PCM (different folks call it different things). It is still in the sealed box as the dealer wants $105 to install it (they tell me that they have to) and flash it. It is the same part number. What is the flash for? Just the VIN?
Anyway, if an of you have any suggestions, I'm up for it! I'm going to replace the coils and module. I'll keep the old stuff in case I'm changing parts that don't need to be changed. It's just baffeling to me that there are no codes. That says ECM to me.
THANKS!
Mark
2004 Cavalier LS Sport
All factory except K&N drop in filter
You realize all the money you spent on parts a shop could have fixed it by now?
Sure toss an ECM at it, and a whole bunch of other @!#$, at some point you will get it right.
I've worked with a few people like you in my career, parts swappers and guess at everything all the time.
- 2004 Cavalier - 124k, owned since new
Wow! Thanks! That was really helpful!
So, how does one become as smart as you? If you had no codes, and no fuel pressure, what would a pro like you have done? If you had no codes, and no spark, what would a pro like you have done? No codes, no spark, no fuel.
Seriously, if you have no intention of being helpful, keep out of it.
Mark
2004 Cavalier LS Sport
All factory except K&N drop in filter
Hmmmm
Well lets see here. No spark and no fuel, I'd find out what the ECM needs to see before it turns on the fuel pump relay and commands the ICM to run. SOME vehicle a faulty crank sensor will kill BOTH spark and the fuel pump, some wont. SOME vehicle a faulty camshaft sensor will kill all together ( Nissans, my speciality)
Once I found that out, I would have a idea where to go, but lets see if we can pick up where you left off. You say the fuel pump relay clicks, so we can assume the ECM is in fact commanding the fuel pump relay on ( heres where knowing what control fuel/spark would be useful)
Do you have wiring diagrams?
So do you have power at the fuel pump?
What did you use to test for spark, btw?
How about the anti-theft system....what is that light doing while cranking????
BTW even through the MIL wasnt on before it died, it may have codes now. From self-test that the ECM does during cranking.....so you may have a fault code and just not know it.
Heres a thought to ponder btw, if you have NO spark and NO fuel pressure, why are you swapping the coil pack for? Obviously something that is controlling fuel/spark is shutting it down.
So like you said, hang on to the old parts because you have swapped a lot of good ones out, your quote about "says ECM to you", well your thinking also said, fuel pump, the fuel pump relay, the crank sensor, and now the coils and ECM. Yes, the ECM needs to be programmed, unless you have a TechII with a subscrpition to GMs tech info you cant do it.
Thats how a pro like me is thinking btw, even though I'm a long ways away from you. Now if it was in front of me I could fix it myself, but theres my two cents on your issue
- 2004 Cavalier - 124k, owned since new
Rob wrote:Hmmmm
Well lets see here. No spark and no fuel, I'd find out what the ECM needs to see before it turns on the fuel pump relay and commands the ICM to run. SOME vehicle a faulty crank sensor will kill BOTH spark and the fuel pump, some wont. SOME vehicle a faulty camshaft sensor will kill all together ( Nissans, my speciality)
Once I found that out, I would have a idea where to go, but lets see if we can pick up where you left off. You say the fuel pump relay clicks, so we can assume the ECM is in fact commanding the fuel pump relay on ( heres where knowing what control fuel/spark would be useful)
Do you have wiring diagrams?
Yes
Rob wrote:So do you have power at the fuel pump?
Intermittently. I will go 10 key on cycles and only hear the pump run once.
Rob wrote:What did you use to test for spark, btw?
Spark plug tester
Rob wrote:How about the anti-theft system....what is that light doing while cranking????
Key to on, the light is on for a few seconds, then goes out. Key to start, theft light is not on.
Rob wrote:BTW even through the MIL wasnt on before it died, it may have codes now. From self-test that the ECM does during cranking.....so you may have a fault code and just not know it.
No codes.
Rob wrote:
Heres a thought to ponder btw, if you have NO spark and NO fuel pressure, why are you swapping the coil pack for?
For one cranking event on cylinder number 3, it had spark, but it was not near as strong as I've seen on any other car I have owned.
Rob wrote:From self-test that the ECM does during cranking.....so you may have a fault code and just not know it. Obviously something that is controlling fuel/spark is shutting it down.
Isn't that what the ECM does?
Rob wrote:So like you said, hang on to the old parts because you have swapped a lot of good ones out
How would we know that the two parts I've swapped are in fact good?
Rob wrote:, your quote about "says ECM to you", well your thinking also said, fuel pump, the fuel pump relay, the crank sensor, and now the coils and ECM.
Again, with no fuel pressure when the pump DID run, yes, I concluded it was the pump. A relay is how much and handy to have for other projects anyway? Crank sensor, since it tells (in the end) the plugs when to fire, yes, I changed it. I have not bought the other parts yet as family life happend. So, I am $300 into it. I have learned the whole way. How much would I be into it with a tow to the dealer (who isn't a dealer anymore thanks to GM, and has sold off a ton of their GM specific stuff)(almost $100), $65 per hour just for time, and paying them for diagnostics instead of me learning, and dealer cost for the two parts I bought? Isnt' this site here for folks to be able to do things themselves and learn from the experience of others? With your first reply, folks should assume that this site shouldn't exist because they are idiots for not taking their car to the shop in the first place.
The 20+ year Air Force Disabled Veteran, who maintained F-15 fighter aircraft and F-117A Stealth fighters without one incedent, likes to do things himself, learning the whole way.
Rob wrote:Yes, the ECM needs to be programmed, unless you have a TechII with a subscrpition to GMs tech info you cant do it.
Thank you for that confirmation. I have read that the car will run without flashing it so I wouldn't have to pay for the tow and I could just drive it there to be flashed.
Rob wrote:Thats how a pro like me is thinking btw, even though I'm a long ways away from you. Now if it was in front of me I could fix it myself, but theres my two cents on your issue
Rob wrote:I've worked with a few people like you in my career, parts swappers and guess at everything all the time.
Yeah, I'm not that bright (see highlighted text above). I still guess with hydraulics, electronics, flight controls, avionics, etc.. I haven't been on a crew for a Super Gas car in Division 7. I blew up my truck when I installed full power/heated seats in it where the driver's seat was four way power and passenger was manual. Going as far as cutting the holes in the doors for the switches, and the computer controlled heaters actually worked. What I'm saying is, please know the person you are defaming before doing it, because you just don't know who has fought for your rights to speak freely. Plus, in your 25ish years of life experience, you should learn that there are always things to learn from more experienced people. You never know, you might post a question that I will reply to.
Thank you for your help,
Mark
2004 Cavalier LS Sport
All factory except K&N drop in filter
my local carmax/chevy dealer had my 99 z24 for 19 days......
turned out to be a bad ecm fuse.
lol.
My car was made with wrenches, Not chopsticks.
WiggyHD wrote:Rob wrote:Hmmmm
Well lets see here. No spark and no fuel, I'd find out what the ECM needs to see before it turns on the fuel pump relay and commands the ICM to run. SOME vehicle a faulty crank sensor will kill BOTH spark and the fuel pump, some wont. SOME vehicle a faulty camshaft sensor will kill all together ( Nissans, my speciality)
Once I found that out, I would have a idea where to go, but lets see if we can pick up where you left off. You say the fuel pump relay clicks, so we can assume the ECM is in fact commanding the fuel pump relay on ( heres where knowing what control fuel/spark would be useful)
Do you have wiring diagrams?
Yes
Great, so what if anything does the fuel pump circuit, and the ICM circuit have in common. Is the fuse good for the ECM?
Rob wrote:So do you have power at the fuel pump?
Intermittently. I will go 10 key on cycles and only hear the pump run once.
Okay
Rob wrote:What did you use to test for spark, btw?
Spark plug tester
Good, I've seen some folks use the engine block to see if the spark would arch across it
Rob wrote:How about the anti-theft system....what is that light doing while cranking????
Key to on, the light is on for a few seconds, then goes out. Key to start, theft light is not on.
Good, we can eliminate that
Rob wrote:BTW even through the MIL wasnt on before it died, it may have codes now. From self-test that the ECM does during cranking.....so you may have a fault code and just not know it.
No codes.
Good deal
Rob wrote:
Heres a thought to ponder btw, if you have NO spark and NO fuel pressure, why are you swapping the coil pack for?
For one cranking event on cylinder number 3, it had spark, but it was not near as strong as I've seen on any other car I have owned.
Lets get it running, than see about the #3 issue.
Rob wrote:From self-test that the ECM does during cranking.....so you may have a fault code and just not know it. Obviously something that is controlling fuel/spark is shutting it down.
Isn't that what the ECM does?
Nevermind, this was related to possible codes, but you have none
Rob wrote:So like you said, hang on to the old parts because you have swapped a lot of good ones out
How would we know that the two parts I've swapped are in fact good?
Well it didnt fix the problem
Rob wrote:, your quote about "says ECM to you", well your thinking also said, fuel pump, the fuel pump relay, the crank sensor, and now the coils and ECM.
Again, with no fuel pressure when the pump DID run, yes, I concluded it was the pump. A relay is how much and handy to have for other projects anyway? Crank sensor, since it tells (in the end) the plugs when to fire, yes, I changed it. I have not bought the other parts yet as family life happend. So, I am $300 into it. I have learned the whole way. How much would I be into it with a tow to the dealer (who isn't a dealer anymore thanks to GM, and has sold off a ton of their GM specific stuff)(almost $100), $65 per hour just for time, and paying them for diagnostics instead of me learning, and dealer cost for the two parts I bought? Isnt' this site here for folks to be able to do things themselves and learn from the experience of others? With your first reply, folks should assume that this site shouldn't exist because they are idiots for not taking their car to the shop in the first place. The 20+ year Air Force Disabled Veteran, who maintained F-15 fighter aircraft and F-117A Stealth fighters without one incedent, likes to do things himself, learning the whole way.
Sounds cool
Rob wrote:Yes, the ECM needs to be programmed, unless you have a TechII with a subscrpition to GMs tech info you cant do it.
Thank you for that confirmation. I have read that the car will run without flashing it so I wouldn't have to pay for the tow and I could just drive it there to be flashed.
No problem
Rob wrote:Thats how a pro like me is thinking btw, even though I'm a long ways away from you. Now if it was in front of me I could fix it myself, but theres my two cents on your issue
Rob wrote:I've worked with a few people like you in my career, parts swappers and guess at everything all the time.
Yeah, I'm not that bright (see highlighted text above). I still guess with hydraulics, electronics, flight controls, avionics, etc.. I haven't been on a crew for a Super Gas car in Division 7. I blew up my truck when I installed full power/heated seats in it where the driver's seat was four way power and passenger was manual. Going as far as cutting the holes in the doors for the switches, and the computer controlled heaters actually worked. What I'm saying is, please know the person you are defaming before doing it, because you just don't know who has fought for your rights to speak freely. Plus, in your 25ish years of life experience, you should learn that there are always things to learn from more experienced people. You never know, you might post a question that I will reply to.
Thank you for your help,
Mark
I try
- 2004 Cavalier - 124k, owned since new
silly question, but is the cigarette lighter fuse shot? Just making sure the obd2 port is powered and your able to communicate to the code reader. also... I am pretty much stumped.
All fuses are good. The code reader communicates, but says it found no codes.
THANKS!
Mark
2004 Cavalier LS Sport
All factory except K&N drop in filter
The fuel pump relay is buzzing after trying to start and returning the key to run position.
Mark
2004 Cavalier LS Sport
All factory except K&N drop in filter
New ICM installed (not coils) and new plugs. Still no start. Gonna double check power to the fuel pump for the 5th time.
Mark
2004 Cavalier LS Sport
All factory except K&N drop in filter
