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Car fires then dies. Or sometimes doesn't start at all.
Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Car fires then dies. Or sometimes doesn't start at all.
Guys, I am at a loss here. Thought I had this fixed and it wasn't.
First it wouldn't start cold. Just cranked. If you kept trying it would eventually start (maybe the 7th or 8th time). Once it started it would start all day.
Then if it would start and run, after 2 minutes of idling the car sometimes would just turn off like someone flipped a switch. I restarted it no problem, and it idled for 20 minutes no issues.
Now it likes to crank, fire, idle for 3-5 seconds then die. When it does idle that little bit giving it throttle has no effect at all.
But sometimes it will also start no issues, one crank, fire right up and stay running.
The car isn't stock. But has all the stock wiring, sensors...etc Here's what I've done:
Datalogged it when it stays running. No codes, all sensors are fine and have normal readings.
New plugs, wires, distributor cap and rotor. New coil. Replaced ICM which didn't help. Key forward the pump primes and I have adequate fuel pressure at the rails. When running, fuel pressure is also ok. When the car idles, tapping the ecm, wiggling the wires behind my ECM, tapping my MAF, wiggling the wiring to my coil, and ICM. Does nothing. Idle doesn't change, car stays running. Also Ohm'ed my injectors, they were ok.
This car ran perfect the 5 years I had the new motor in it. I changed nothing and this started happening. I'm starting to pull out my hair here.
Re: Car fires then dies. Or sometimes doesn't start at all.
The distributor is a MSD 8366. It's 5 years old. I was told a bad pickup won't even fire the car? Maybe I was misinformed?
Edit: Just searched and found this "One of the first symptoms of a bad ignition pickup is an engine that stalls. An old or failing ignition pickup may cut out signal intermittently, which may cause the engine to stall. The engine may suddenly just shut off, almost as if the key had been turned off. Depending on the nature of the issue, sometimes the vehicle can be restarted and driven again after a brief period of time. However, this problem will persist and worsen until it is taken care of. Another common symptom of a bad or failing ignition pickup is a vehicle that does not start. If the ignition pickup fails, it will not provide the signal necessary for the vehicle’s ignition system to operate, and as a result the engine will not start or run."
Today when it wouldn't start, for the heck of it, I disconnected my TPS. The car started and stayed running. So I turned it off, plugged it back in. And then it still fired up no issues. So I'm thinking that was just a coincidence. Thank you for the reply!
Last edited by IROCThe5.7L; 07-20-2018 at 06:36 PM.
Re: Car fires then dies. Or sometimes doesn't start at all.
Hate to bump this. But I replaced the pickup coil and it’s still doing the same thing. Will fire, idle for a few seconds then die. I eventually got it to idle and it just turned off after a minute. Restarted it. Ran for 30 minutes no issues. Started it 10 times. Fired and idled every time. This seems only to be a cold start issue. When it does fire and idle those few seconds. Giving throttle has no effect.
I have no CSI and nothing has changed. Even the tune is the same. It would fire up on one crank for years. I’m at a total loss. Checked my base timing. That’s fine and didn’t move.
Re: Car fires then dies. Or sometimes doesn't start at all.
When it cranks but doesn't fire, does it not have fuel or not have spark? Or does it have them both? Or neither? At least start there so you know closer to what circuit to troubleshoot down
Re: Car fires then dies. Or sometimes doesn't start at all.
It hasn’t done that in a while now. I was hoping it would so I could see. Now it cranks, fires and dies like in the video.
Ive checked for spark when it starts and dies. It’s a nice white spark. I have 40+ lbs at the rail when cranking. When it dies I can hear the fuel pump running for a few seconds then turn off. So it’s getting spark and fuel. I think tomorrow I’m going to unplug the MAF and see how it starts cold.
Last edited by IROCThe5.7L; 07-25-2018 at 06:07 PM.
Re: Car fires then dies. Or sometimes doesn't start at all.
Originally Posted by IROCThe5.7L
.......It’s a nice white spark.....
White isn't nice , it's weak . You want a nice FAT BLUE spark that'll jump better than a 1/2" gap with a loud prominent "SNAP !"
Tell me , do you by chance have one of those dreadful "MSD Blaster" coils to go along with your MSD distributor ? Personally I do believe it sounds spark related and just for grins if it were mine I'd try running a bone stock GM HEI just to see if the MSD is actually at fault .....
Re: Car fires then dies. Or sometimes doesn't start at all.
When you checked the sensors, what were the readings at idle or key on engine off? Your video sounds more like it peters out then dies rather than just turning off. So, coolant temp and tps voltage are the big ones I would start with since everything is cold. You are obviously getting fuel and spark since it does fire even if for a short period.
Re: Car fires then dies. Or sometimes doesn't start at all.
Originally Posted by OrangeBird
White isn't nice , it's weak . You want a nice FAT BLUE spark that'll jump better than a 1/2" gap with a loud prominent "SNAP !"
Tell me , do you by chance have one of those dreadful "MSD Blaster" coils to go along with your MSD distributor ? Personally I do believe it sounds spark related and just for grins if it were mine I'd try running a bone stock GM HEI just to see if the MSD is actually at fault .....
I was always under the impression white/blue is good. Red/orange is weak. I had a 10 year old coil in it that I thought was the issue and it wasn’t. So I got a new blaster coil. I don’t think both are bad. The car fires up good. It just doesn’t want to idle. When it stays running. Car runs good. Crisp throttle response...etc.
Originally Posted by PaulyC
When you checked the sensors, what were the readings at idle or key on engine off? Your video sounds more like it peters out then dies rather than just turning off. So, coolant temp and tps voltage are the big ones I would start with since everything is cold. You are obviously getting fuel and spark since it does fire even if for a short period.
The car will try and idle for that few seconds. But when I get it running and it’s cold. About 1-2min into idle. Sometimes it will turn off like someone flipped a switch. I’ll restart it. And it will idle for 30+ min no issues. Fire up fine. I can’t wrap my head around what could be malfunctioning cold. But be fine when the engines warmed up.
I datalogged car when it was warmed up and would run. All sensors were ok. Next step is to datalog on a cold start and hope it stalls and maybe I can go some info. Hopefully the ecm cooperates. We all know how much the 165’s like to spit out data. Lol.
Re: Car fires then dies. Or sometimes doesn't start at all.
Well tried to datalog a cold start. And of course the ECM wouldn't cooperate and spit out the data. So I started the car, and it fired up on one crank. Idled to closed loop with no issues. Took it for a quick spin, drove great, ton of power. It did seem to run richer than normal. I wish whatever was crapping out would just die so I could solve this.
Re: Car fires then dies. Or sometimes doesn't start at all.
Welp, finally got a datalog when the car doesn't wanna stay running. Nothing really sticks out. I uploaded my datalogs if anyone want to take a look (tuner pro). Only thing I really noticed is when it's dying, my load variable shoots though the roof, but I think that's normal because it's trying to stay running? I have stored codes from unplugging the MAF and TPS, checking timing...etc Weird thing is that it shows the stored codes (no ses light when running). But when it started and ran fine, it showed no stored codes. All datalogs were taken in a 15 minute period.
It's got fuel, spark, fires in one crank. Nothings changed on the car or tune. Every ignition piece has been replaced. I have a spare MAF hanging around, might throw that in even though it looks fine in the logs, The maybe replace ECM and throw my old distributor back in. Other than that I'm out of ideas.
Before I started it:
And here's a snip of it in the middle of dying:
Last edited by IROCThe5.7L; 08-01-2018 at 02:58 PM.
Re: Car fires then dies. Or sometimes doesn't start at all.
Originally Posted by IROCThe5.7L
Welp, finally got a datalog when the car doesn't wanna stay running. Nothing really sticks out. I uploaded my datalogs if anyone want to take a look (tuner pro). Only thing I really noticed is when it's dying, my load variable shoots though the roof, but I think that's normal because it's trying to stay running? I have stored codes from unplugging the MAF and TPS, checking timing...etc Weird thing is that it shows the stored codes (no ses light when running). But when it started and ran fine, it showed no stored codes. All datalogs were taken in a 15 minute period.
It's got fuel, spark, fires in one crank. Nothings changed on the car or tune. Every ignition piece has been replaced. I have a spare MAF hanging around, might throw that in even though it looks fine in the logs, The maybe replace ECM and throw my old distributor back in. Other than that I'm out of ideas.
Before I started it:
And here's a snip of it in the middle of dying:
This thread died with no resolution… I have same issue did you ever figure it out?
Re: Car fires then dies. Or sometimes doesn't start at all.
Originally Posted by BlksIrocZ
This thread died with no resolution… I have same issue did you ever figure it out?
Well I'm pretty disappointed in myself-lol I always try to make sure I update posts when a solution is found. I believe I had another thread open in the TPI or DIY Prom forum where this got resolved. So long story short I had spark. The white spark I was seeing on my spark tester was fine. I had 40+ psi at the rails. My injectors were firing as it would start almost all the time. So I figured it had to be a sensor, ICM, Pickup coil...etc Everything checked out fine. I finally went to Autozone and got a noid light kit. I unplugged one of my injectors and connected the noid light. I had the wife crank the car and the noid light was flashing. Car fires and is idling all while the noid light is flashing. Then I see the noid light stop flashing. A few seconds later the car stops running like someone flipped a switch. After some more digging it appeared the injector driver in the ECM was failing. I replaced the ECM and the car has been fine ever since.
Re: Car fires then dies. Or sometimes doesn't start at all.
Originally Posted by IROCThe5.7L
Well I'm pretty disappointed in myself-lol I always try to make sure I update posts when a solution is found. I believe I had another thread open in the TPI or DIY Prom forum where this got resolved. So long story short I had spark. The white spark I was seeing on my spark tester was fine. I had 40+ psi at the rails. My injectors were firing as it would start almost all the time. So I figured it had to be a sensor, ICM, Pickup coil...etc Everything checked out fine. I finally went to Autozone and got a noid light kit. I unplugged one of my injectors and connected the noid light. I had the wife crank the car and the noid light was flashing. Car fires and is idling all while the noid light is flashing. Then I see the noid light stop flashing. A few seconds later the car stops running like someone flipped a switch. After some more digging it appeared the injector driver in the ECM was failing. I replaced the ECM and the car has been fine ever since.
good to know i checked my injectors and changed ecm, iac, maf, tps, plugs , wires, cap, rotor changed intake gaskets and runners and all vacum lines, fuel pump and filter (44psi steady at rail)
no engine codes
only starts fine with maf unplugged runs fantastic but i changed maf three times to try and changed maf power and burnoff relay, and ecm twice….
its three years of misery i have no idea whats up and its disheartening… only happens after sitting all night (or all day 8 hours or more) start stall start stall keep throttling off on then will run fine (if i hold throttle it will stall also) have to go off and on for a few minutes
Re: Car fires then dies. Or sometimes doesn't start at all.
Did you check your wiring going to the MAF? Are you able to datalog?
Originally Posted by BlksIrocZ
good to know i checked my injectors and changed ecm, iac, maf, tps, plugs , wires, cap, rotor changed intake gaskets and runners and all vacum lines, fuel pump and filter (44psi steady at rail)
no engine codes
only starts fine with maf unplugged runs fantastic but i changed maf three times to try and changed maf power and burnoff relay, and ecm twice….
its three years of misery i have no idea whats up and its disheartening… only happens after sitting all night (or all day 8 hours or more) start stall start stall keep throttling off on then will run fine (if i hold throttle it will stall also) have to go off and on for a few minutes
07-20-2018, 05:56 PM
White isn't nice , it's weak . You want a nice FAT BLUE spark that'll jump better than a 1/2" gap with a loud prominent "SNAP !" 
