Car just died while idling at an intersection
Car just died while idling at an intersection I have not had this car just die on me before. I took it on a 2,000 mile road trip to California and back in June with no problems. It's been my daily driver since the weather dried up. Two days ago I had just driven 80 miles on the freeway and was waiting in a left turn lane when the engine started to idle rough. It sounded like it was almost dying then catching itself but finally died. I tried to start it about 4 times and it would fire up then die, even if I gave it gas. When it finally started I got onto a side road and drove at 20 mph at about 2,000 rpm in 2nd gear. There were a few times it tried to die even then. Looking at my scanmaster, I noticed the O2 millivolts on both sides would drop to nothing when the engine almost died. Once in my driveway, I was letting it idle and started to cycle through the sensors on my scanmaster when it died again.
This morning I ran some errands with it and it ran fine.
I was suspecting the heat. It has never ran very well when it's hot out, like 80's or higher. I'll notice on my scanmaster, the pcm is constantly pulling timing when the outside temp gets high, no matter if I'm in town or on the highway.
This morning I ran some errands with it and it ran fine.
I was suspecting the heat. It has never ran very well when it's hot out, like 80's or higher. I'll notice on my scanmaster, the pcm is constantly pulling timing when the outside temp gets high, no matter if I'm in town or on the highway.
So it acted up again today. This time I got some trouble codes that I hope will shed some light on the issue.
18 - injector circuit
42 - ignition control circuit (shorted or grounded)
51 - eeprom programming error
I was running errands and drove about 35 miles around town with the AC running. My scanmaster showed coolant temp reached 214 degrees as I was heading home when I felt the throttle first become unresponsive, as if I was out of gas. I turned off the AC and drove a few more miles and the temp dropped to 193 degrees before it died at an intersection. I got it to some shade and let it cool for about 10 minutes. After that, even though coolant temp was at about 185 degrees, I could only drive it a half mile at a time before it died. It died four times like this the rest of the way home. I would have to wait a few minutes before it would start. While driving or idling it would start to die and be barely hanging on, lots of shaking. If I ever gave it gas at this point, it would die instantly and smelled strongly of gas.
I looked at as many scanmaster readings as I could through all this.
O2 millivolts were down around 7 like last time.
LBL/ RBL were up at 160.
Lin/rin were up at 194.
EGR kept quickly bouncing from 0 to 12 and back.
I checked the connections at the injectors, ICM and PCM and they were tight. The PCM was piping hot to the touch though. I did the ICM cooling mod mentioned on shoebox's site and it wasn't as hot as the PCM.
That's all the info I can think of right now. Could the PCM just be getting heat soaked on these hot days?
18 - injector circuit
42 - ignition control circuit (shorted or grounded)
51 - eeprom programming error
I was running errands and drove about 35 miles around town with the AC running. My scanmaster showed coolant temp reached 214 degrees as I was heading home when I felt the throttle first become unresponsive, as if I was out of gas. I turned off the AC and drove a few more miles and the temp dropped to 193 degrees before it died at an intersection. I got it to some shade and let it cool for about 10 minutes. After that, even though coolant temp was at about 185 degrees, I could only drive it a half mile at a time before it died. It died four times like this the rest of the way home. I would have to wait a few minutes before it would start. While driving or idling it would start to die and be barely hanging on, lots of shaking. If I ever gave it gas at this point, it would die instantly and smelled strongly of gas.
I looked at as many scanmaster readings as I could through all this.
O2 millivolts were down around 7 like last time.
LBL/ RBL were up at 160.
Lin/rin were up at 194.
EGR kept quickly bouncing from 0 to 12 and back.
I checked the connections at the injectors, ICM and PCM and they were tight. The PCM was piping hot to the touch though. I did the ICM cooling mod mentioned on shoebox's site and it wasn't as hot as the PCM.
That's all the info I can think of right now. Could the PCM just be getting heat soaked on these hot days?
I would start by changing the rear bumper and work forward. At some point you'll replace the bad part. Or you can actually troubleshoot, find the problem and fix it. shbox.com is a good place to start.
Al 95 Z28
Al 95 Z28
I'll clear the codes and run some more errands today. Based on others' advice, I'm going to keep an eye on voltage. Someone thought a low voltage could be causing my weird codes.
shbox and nitrous: I'll carry my fuel pressure gauge in the car from now on and if this happens again, I'll hook it up and read the fuel pressure.
shbox and nitrous: I'll carry my fuel pressure gauge in the car from now on and if this happens again, I'll hook it up and read the fuel pressure.
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Verdad Gallardo Got a new surprise today. On the highway I had my cruise set at 80 mph and within about 15 minutes of starting the drive it began running rough. I noticed the LBL was at 108, RBL was at 160. I remember rin was at 196, and right injector pulse width was up near 10. Left O2 wasn't moving outside of 400-500 millivolts. Right O2 was bouncing from 0-999 like normal. Then I get a code 63 for Right O2 open circuit. It smelled strongly of gas for the next 10 minutes or so when I noticed fuel trims were returning to normal and everything else was go back to normal. For the next 15 miles or so, the sensors would intermittently go wacky then level off. After that for the next 60 miles it ran perfectly. After all this weird behavior, could my PCM be going bad? I'm also pretty suspicious about the PCM because of the eeprom error combined with the injector circuit error. The battery voltage was between 12.5 and 13.2 throughout the drive. So far it seems like if I start looking where the dtc's and sensors are telling me to start, I'd be checking every component in the engine management system.
Teching In
Joined: Nov 2009
Posts: 34
Likes: 0
Got a new surprise today. On the highway I had my cruise set at 80 mph and within about 15 minutes of starting the drive it began running rough. I noticed the LBL was at 108, RBL was at 160. I remember rin was at 196, and right injector pulse width was up near 10. Left O2 wasn't moving outside of 400-500 millivolts. Right O2 was bouncing from 0-999 like normal. Then I get a code 63 for Right O2 open circuit. It smelled strongly of gas for the next 10 minutes or so when I noticed fuel trims were returning to normal and everything else was go back to normal. For the next 15 miles or so, the sensors would intermittently go wacky then level off. After that for the next 60 miles it ran perfectly. After all this weird behavior, could my PCM be going bad? I'm also pretty suspicious about the PCM because of the eeprom error combined with the injector circuit error. The battery voltage was between 12.5 and 13.2 throughout the drive. So far it seems like if I start looking where the dtc's and sensors are telling me to start, I'd be checking every component in the engine management system.
One of the things I wanted to test was the possibility of AC volts leaking from the alternator and screwing with my PCM. I used my multimeter to test from the alternator lug to the negative battery terminal and got 25 volts! This seemed unlikely so I took it to a friend's shop and had them test with their multimeter and they got zero. They also hooked up this big green diagnostic device which gave my electrical system the OK.
It started acting up again and dying on me so I hooked up my fuel pressure gauge and let it idle in my driveway. With key on, it showed 40 psi. With engine idling it showed 35 psi. As it idled, I watched the gauge slowly fall to 10 psi at which point it would try to die and idle rough, then shoot quickly back up to 35 psi and be OK. It did this about 5 times in the 5 minutes I had it idling in my driveway before I gave it some throttle at 10 psi to see what would happen and it died.
So I guess this changes things. Should I be looking at the fuel pump at this point?
It started acting up again and dying on me so I hooked up my fuel pressure gauge and let it idle in my driveway. With key on, it showed 40 psi. With engine idling it showed 35 psi. As it idled, I watched the gauge slowly fall to 10 psi at which point it would try to die and idle rough, then shoot quickly back up to 35 psi and be OK. It did this about 5 times in the 5 minutes I had it idling in my driveway before I gave it some throttle at 10 psi to see what would happen and it died.
So I guess this changes things. Should I be looking at the fuel pump at this point?
Teching In
Joined: Mar 2010
Posts: 25
Likes: 0
From: Vancouver
Im having the same problem i would be driving and it would be fine then it would start to idle really rough and smoke would be coming out of the exhaust and i pump the gas and it doesnt want to go and then after pumping some more it picks up then starts to go then starts to die, then the fan would kick on with the service engine light then it would run fine.
The pump connecter gets its 12 volts with key on. I'd be interested to see the volts with engine running and while it's running poorly. Does anyone know a method to do this before I go rigging something up myself?
I drove 60 miles on the highway today with no problems. As soon as I came to a prolonged stop, it died while idling, no codes. Started it a few minutes later and drove 60 miles back with no problems again. Once I was in town doing 35 mph at about 2000 rpm, it would do this thing where the car acted as if I ran out of gas for a second then the power would come back for a second or two, then cut out, then come back. Like the gas would be cut off, then come back, then cut off. It did this for a few minutes because I never had to stop. Once I pushed the clutch in to make a turn, it died.
I would hate to think this is fuel pump because it's only a year and a half old. On top of that, why am I getting weird codes if it's just the pump?
I drove 60 miles on the highway today with no problems. As soon as I came to a prolonged stop, it died while idling, no codes. Started it a few minutes later and drove 60 miles back with no problems again. Once I was in town doing 35 mph at about 2000 rpm, it would do this thing where the car acted as if I ran out of gas for a second then the power would come back for a second or two, then cut out, then come back. Like the gas would be cut off, then come back, then cut off. It did this for a few minutes because I never had to stop. Once I pushed the clutch in to make a turn, it died.
I would hate to think this is fuel pump because it's only a year and a half old. On top of that, why am I getting weird codes if it's just the pump?
TECH Regular
Joined: May 2010
Posts: 481
Likes: 0
Im having a similar problem, take the vacuum line off the fuel pressure regulator and see what your pressure does. Mine right now is 39 at idle and I have seen it drop to 35, but with the regulator unpluged, it'll stay at 44lbs no matter what, so im gonna drive it around a while with the gauge poking through the hood so I can see what the fuel pressure is while im driving, I know its ghetto fabulous, but hey sometimes you gotta do what you gotta do to figure a problem out.
idformula: I've actually already done those. Fuel gauge duct taped to the windshield and all 
Pressure was solid at 35 psi during my driving and about 42 psi during WOT. The only time I saw a dip was when I described above.
I'm really digging my heels in about replacing that pump. I completely forgot that the pump has a relay behind the dead pedal. I pulled the relay and saw this:
That black prong is #87. #'s 30, 85 and 86 are the good ones. Is this cause for concern? Maybe overdraw on the circuit? Like I said, electricity and anything having to do with it are beyond me for the most part.
Pressure was solid at 35 psi during my driving and about 42 psi during WOT. The only time I saw a dip was when I described above. I'm really digging my heels in about replacing that pump. I completely forgot that the pump has a relay behind the dead pedal. I pulled the relay and saw this:
That black prong is #87. #'s 30, 85 and 86 are the good ones. Is this cause for concern? Maybe overdraw on the circuit? Like I said, electricity and anything having to do with it are beyond me for the most part.
I installed the Racetronix fuel pump wire harness to rule out the pump not getting enough juice. After an hour of stop and go driving in 90 degree weather, it ran great. Once I turn on the A/C, it will have an intermittent issue where it will idle and run fine, then every minute or so I'll hear the fans click on (even though they should be on already correct?) and my O2 millivolts will bottom out in both banks to about 50. Idle gets rough but after a few seconds it's all good again.
I'm going to replace the big 3 (Battery to chassis, battery to alt, block to chassis) with some 0 or 2 gauge and see if that solves anything. I also want to make sure I have a 140 amp alternator. I was thinking about going even more powerful, like a 160 or 200. Anyone have any recommendations as far as where to buy a new alternator with higher amperage?
As a side note, I started a thread in March that asks about the same issue but I forgot about this thread. Here's the link to new one: https://ls1tech.com/forums/lt1-lt4-m...aning-out.html I'm going to continue with this one.
I'm going to replace the big 3 (Battery to chassis, battery to alt, block to chassis) with some 0 or 2 gauge and see if that solves anything. I also want to make sure I have a 140 amp alternator. I was thinking about going even more powerful, like a 160 or 200. Anyone have any recommendations as far as where to buy a new alternator with higher amperage?
As a side note, I started a thread in March that asks about the same issue but I forgot about this thread. Here's the link to new one: https://ls1tech.com/forums/lt1-lt4-m...aning-out.html I'm going to continue with this one.
Launching!
Joined: Jul 2011
Posts: 286
Likes: 0
From: Horn Lake, MS
I replaced alt-battery, chassis-battery, block-battery, block-chassis with wires ranging from 4 to 0 gauge. My volt reading is a whole volt higher than what it has been and it's more stable. Volts used to start out around 13.5 but would gradually drop to about 12.7 the longer I drove. I would also see the dash gauge tick with the blinker. Now volts are a steady 13.7. They did drop to 13.4 by the end of my 20 minute drive though.
Alternator is next on the list. I inspected it to see exactly what it was since I forgot and it's a re-manufactured Delco unit by Autolite, 120 amps. I wouldn't mind having a brand new 140 or 160 amp unit just for peace of mind.
Alternator is next on the list. I inspected it to see exactly what it was since I forgot and it's a re-manufactured Delco unit by Autolite, 120 amps. I wouldn't mind having a brand new 140 or 160 amp unit just for peace of mind.
