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Hello, been reading on these forums awhile but I’m having issues so I signed up to see what you might think.
bought a 2015 stingray that would die while driving and not restart until it cooled down. While searching for the issue Turns out the thrust bearing was trash. Had engine rebuilt, new crank,rods, pistons etc. new engine is in and runs, drove car 6 miles and it died again, crank but no start. I have spark and will be checking fuel later today but it will probably restart since it’s cool now.
has anyone had their car die while driving and not restart while engine is hot?
If you have spark it rules out a crank sensor so I’d be looking at the fuel pump circuit…with heat comes resistance so you should be checking the circuit using voltage drop if you know how to do that.
Is there a schrader valve to test low side fuel pressure? Or is it only high side? I’m not at the car right now, but trying to test high and low separate.
Yes I seen rail pressure in hp tuners. Was getting 200 or so during cranking no start. Not sure what it should be. Is there a gauge for low side.? Thanks for answering, I’m slow today. Spent all days putting engine in yesterday and today I’m beat. Need coffee
To accurately diagnose this a lab scope is needed to check the PWM signal from the module…I use one on many diagnostics but unfortunately dealerships and almost all general repair shops DON’T so they will only guess if you take the car to one of those !!…it can be a bad module, a bad low pressure fuel pump, or a bad high pressure fuel pump..the wiring will also have to be checked for excessive voltage drop due to possible bad connections…now it can be a bad crank sensor if it’s not starting..just look at the Tach while it’s cranking..,no tach movement is most likely a crank sensor…crank sensor fires the spark and injectors.
Hello C5Diag. Is that a special edition of AllDATA? I don't remember seeing that type of information last time I had a subscription. From what I remember, it was very basic.
Last edited by frankbicknell; Jul 16, 2024 at 11:51 AM.
Hello C5Diag. Is that a special edition of AllDATA? I don't remember seeing that type of information last time I had a subscription. From what I remember, it was very basic.
That is Alldata DIY info I posted…not the Pro edition but I don’t really see a difference between the two and for only $19.99 a month that’s not bad for the person that only needs service information infrequently…I’ve also used Mitchell but prefer Alldata.
Yes I seen rail pressure in hp tuners. Was getting 200 or so during cranking no start. Not sure what it should be. Is there a gauge for low side.? Thanks for answering, I’m slow today. Spent all days putting engine in yesterday and today I’m beat. Need coffee
Mike , just checking if you did the torque tube propeller shaft installation procedure . Not doing this is what wipes out the thrust bearing
When it dies, does it just shut off instantaneously, or is it a sputtering death. You didn't say, but that would be the difference between electrical or a mechanical issue.
The engine just stops. Dashboard and everything still on. It’s never died on the highway, it always dies at low speed, stop signs, turn around in driveways. After it dies it just cranks but no start. The next day it starts up and idles rough for a few seconds.Today ran the car for 2 hours so far and nothing happened today.
Mike , just checking if you did the torque tube propeller shaft installation procedure . Not doing this is what wipes out the thrust bearing
Dave
yes I followed the procedure for it when I installed new engine. Took new engine for a drive went about 5-6 miles and it died. Thought previously it was dying out due to the wiped thrust bearing.
Any mods to the car? Any tuning updates? Any sensors replaced with non-OEM sensors? Small black wire attached securely to the battery and the battery cables are securely attached? Any codes stored? Any CEL?
Did you check that all the connectors are fully seated and none were broke during engine replacement? My shop experience was a car that came home with a multitude of broken connectors which seated but were not secure.
Any mods to the car? Any tuning updates? Any sensors replaced with non-OEM sensors? Small black wire attached securely to the battery and the battery cables are securely attached? Any codes stored? Any CEL?
Did you check that all the connectors are fully seated and none were broke during engine replacement? My shop experience was a car that came home with a multitude of broken connectors which seated but were not secure.
no connectors broke. I originally believed that this problem was caused by the excessive thrust bearing wear. .500. Couldn’t believe car actually ran. Only mod is aa supercharger but that was bolted on with the new engine. It has a base tune but again this problem existed before. I thought I had it solved with the new engine.
anyway drove it around my area today for about 2 hours and not an issue. I need it to come back so I can track it down. Codes from today
After re-reading your posts. 200psi on the high side is quite low.
At 400rpm....so basically cranking rpm....the PCM is commanding 290psi at 0.6g of air. For a stock LT1, the below table is what the commanded fuel pressure looks like. The fuel pressure values are in MPa, so multiply by ~145 to get to "psi"
Also....there's a fuel pump check valve in the line that's on the driver's side and goes under the intake to the HPFP. Could be the check valve is bad and sticking or clogging when it heats up since the feed is from the low side *to* the high side. Many people run without the check valve if you do a forum search. I think it's there to prevent fuel line hammer but that's just my speculation. Anyway....might be worth pulling the intake and the line to take a peek.
Lastly.....I found one of my logs from last year where I was looking at fuel pressure (among other things). While not at startup, you can see at hot idle where it is as a point of comparison if you log a similar condition...
Last edited by 96GS#007; Jul 15, 2024 at 08:38 PM.
the check valve is something i started thinking about today. one time it died out and would not restart. i disconnected the fuel line at the intake to see if fuel was flowing and it started up. only problem is i need it to start acting up.
Could be a marginal HPFP. I'd log the fuel pressure while driving. Eventually you'll catch it when it dies and refuses to start. What you see before it dies can often be as important as after it dies and while trying to get it running again.
As mentioned above, you shouldn't be seeing anything under ~300psi at the lower rpms.
That is Alldata DIY info I posted…not the Pro edition but I don’t really see a difference between the two and for only $19.99 a month that’s not bad for the person that only needs service information infrequently…I’ve also used Mitchell but prefer Alldata.
Thank you. I have re-subscribed. It has really improved since the last time I used this service.
C7 dies while driving
