No start issue 20 miles after tune.
12-12-2014, 04:22 PM
#1
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No start issue 20 miles after tune. I recently had my car tuned and some minor issues repaired after installing my 408/TH350 combo. At the shop it drove well and ran strong. The night I got it back, we took it off the trailer and went for a drive to pick up my buddies car. On the way there, everything was great, ran perfectly and had no issues. Then on the way back the car started to lose power and die out every time I came to a stop. It would start back up but then die out the next time I came to a stop. It finally died without starting at a stop sign and I had to push it in to a parking lot. I looked down at my fuel gauge and it read empty. I felt like an idiot and figured I ran out of gas. We got some gas, put 3 gallons in it and it still wouldn't start. We listened and couldn't hear the fuel pump when I cycled the key from OFF to RUN and couldn't smell fuel at the exhaust when cranking. Next thing I thought was I burned up the fuel pump. Had to have the car towed back to my house. Ordered a new Racetronix FP. It got here this afternoon, I opened up the fuel tank and it was almost full, much more fuel than we had put in the previous night. There's fuel in the tank, and a new FP. Still can't hear it cycle. I bought a new FP relay, still won't cycle. The gauge still reads completely empty with fuel in the tank. Checked fuses and they're good. I'm getting 12.7V at the fuse under the hood. Any ideas? I want to drive her SO BAD!!!
12-13-2014, 12:56 PM
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Does anyone have a wiring diagram? I'm trying to trace the wires but no luck. It goes in to a big harness. There's a big connector in front of the rear axle but it doesn't go through the car.
12-14-2014, 05:12 PM
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One more update; I replaced my fuel filter just to be sure there is no clog and no change. Lots of fuel came out when I removed the old filter. Just to be sure I didn't have a spark AND fuel issue I sprayed some ether in the intake and it just cranked like normal, no ignition. I placed a plug tester on to my #1 plug wire and no spark. ALL fuses and relays are getting voltage. Could it be my PCM? Dash lights work but fuel gauge still reads empty.
12-17-2014, 01:35 PM
#6
the 2 things that stand out are you have a new motor/trans and you had a computer tune.
regarding the tune since the car was running i would be inclined to think a bad tune would not be your problem, but that's an assumption on my part because i don't know everything about gm pcm programming.
you said there's a new motor/trans combo, so that means the original was pulled out... the body was lifted off? and there were some other minor issues, what?
i would first check wiring harness to make sure nothing was pinched, chaffed, or wire pulled out of a pin connector because of the mechanical work done on car.
you said you fuel gauge reads empty, the fuel gauge on dash is driven by the computer (for lack of better description) in the gauge cluster... the gauge cluster is practically it's own computer. it receives network data from the PCM telling it what to point the gauge needles to. do your other gauges come to life at all? guessing you might have a CAN bus problem which would then prevent engine starter from engaging.
and by no start you mean you turn ignition key to start and starter does nothing all quiet? or does engine turn over but never runs?
the other thing obviously is are there any DTC's stored? have you used a scanner connected to the OBD2 port to see?
i can look up wiring diagrams in my service manual, but off top of my head the few things that would prevent the starter from engaging and fuel pump kicking on are
- VATS triggered by ignition key resistor or something else gone bad in VATS system
- clutch not pushed in on manual trans car or not in park/neutral on auto trans car, if pcm and or bcm does not see that signal then starter won't engage, but fuel pump would still cycle.
- alarm system is active/activated preventing engine starter crank
- relay or fuse bad in underhood fuse box related to engine starting and BCM, preventing starter crank would have to look up wiring diagrams
regarding the tune since the car was running i would be inclined to think a bad tune would not be your problem, but that's an assumption on my part because i don't know everything about gm pcm programming.
you said there's a new motor/trans combo, so that means the original was pulled out... the body was lifted off? and there were some other minor issues, what?
i would first check wiring harness to make sure nothing was pinched, chaffed, or wire pulled out of a pin connector because of the mechanical work done on car.
you said you fuel gauge reads empty, the fuel gauge on dash is driven by the computer (for lack of better description) in the gauge cluster... the gauge cluster is practically it's own computer. it receives network data from the PCM telling it what to point the gauge needles to. do your other gauges come to life at all? guessing you might have a CAN bus problem which would then prevent engine starter from engaging.
and by no start you mean you turn ignition key to start and starter does nothing all quiet? or does engine turn over but never runs?
the other thing obviously is are there any DTC's stored? have you used a scanner connected to the OBD2 port to see?
i can look up wiring diagrams in my service manual, but off top of my head the few things that would prevent the starter from engaging and fuel pump kicking on are
- VATS triggered by ignition key resistor or something else gone bad in VATS system
- clutch not pushed in on manual trans car or not in park/neutral on auto trans car, if pcm and or bcm does not see that signal then starter won't engage, but fuel pump would still cycle.
- alarm system is active/activated preventing engine starter crank
- relay or fuse bad in underhood fuse box related to engine starting and BCM, preventing starter crank would have to look up wiring diagrams
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12-17-2014, 02:56 PM
#8
http://fastfieros.com/tech/gm_vats_passkey.htm
VATS = vehicle anti-theft system, also known as passkey, and is the system in the ignition circut that uses the resistor chip in the ignition key.
it prevents the starter from ever engaging to crank the engine over, and the security light on the dash will be illuminated. when you turn the ignition key to the start position, nothing happens everything is silent.
no security system that is operating properly will shut off a running engine, especially when in drive and car is going down the road that is a huge liability. at best computer programming might kill an idling engine that knows the car is in park and not moving, but that is not the case on 4th gen f-bodies.
VATS = vehicle anti-theft system, also known as passkey, and is the system in the ignition circut that uses the resistor chip in the ignition key.
it prevents the starter from ever engaging to crank the engine over, and the security light on the dash will be illuminated. when you turn the ignition key to the start position, nothing happens everything is silent.
no security system that is operating properly will shut off a running engine, especially when in drive and car is going down the road that is a huge liability. at best computer programming might kill an idling engine that knows the car is in park and not moving, but that is not the case on 4th gen f-bodies.
Last edited by 1 FMF; 12-17-2014 at 03:09 PM.
12-18-2014, 11:00 PM
#10
Vats will cause no noise similar to a dead starter but the car will cycle the fuel pump. The security light will stay illuminated But when you turn the key nothing happens
No fuel, no spark, check your main engine fuse. You could have shorted an 02 sensor
Also replace the crank sensor, it can cause no start issues
Last option is the ECM was fried from an incorrect ground
12-19-2014, 07:31 AM
#11
False, that is only true for gm trucks and vans. The fbody used ignition modules from early gen resistor keys while the trucks used the in key resistor.
Vats will cause no noise similar to a dead starter but the car will cycle the fuel pump. The security light will stay illuminated But when you turn the key nothing happens
No fuel, no spark, check your main engine fuse. You could have shorted an 02 sensor
Also replace the crank sensor, it can cause no start issues
Last option is the ECM was fried from an incorrect ground
Vats will cause no noise similar to a dead starter but the car will cycle the fuel pump. The security light will stay illuminated But when you turn the key nothing happens
No fuel, no spark, check your main engine fuse. You could have shorted an 02 sensor
Also replace the crank sensor, it can cause no start issues
Last option is the ECM was fried from an incorrect ground
I'm going to tell you the 1st thing you need to do. 1st find whom ever constructed the car to get a complete picture of what it is you are exactly working on. Year, mods, if it has VATS etc then post up the year and system mods THEN someone can help you.
How can anyone help you if you don't eat yer meat? you can't have a running car if you don't eat yer meat.
Last edited by RockinWs6; 12-19-2014 at 07:36 AM.
12-19-2014, 10:56 AM
#12
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I checked codes and there are none. The motor will turn over but not fire up. All grounds are in place on the L and R sides of the block and the back side of the driver's side cylinder head. There are grounding wires and straps to the frame from the block.
My car is a 2000 Z28. It previously ran the stock LS1 with a Tv.2 cam and T56. I put a HKE built 408 with a TH 350 behind it. It ran fantastic for about ten miles until the symptoms started (felt like I was running out of fuel). When I turn the key to run my gauges illuminate. Fuel gauge reads below E and if I turn the engine over for more than a few seconds my oil pressure gauge rises.
I figured it was a fuel and pump issue until I replaced the pump and did not hear it cycle. I checked voltage at the connector at the pump when the key was cycled and there was no voltage. I replaced the FP relay and every fuse is getting power with all the fuses pins intact in the fuse block.
I sprayed some ether into the intake and cranked it over and no start or fire. I checked a plug wire and confirmed there was no spark to the plugs either. Ignition relay was swapped/checked and no change.
I have not attempted to start it with my extra key and will try that later this afternoon.
My car is a 2000 Z28. It previously ran the stock LS1 with a Tv.2 cam and T56. I put a HKE built 408 with a TH 350 behind it. It ran fantastic for about ten miles until the symptoms started (felt like I was running out of fuel). When I turn the key to run my gauges illuminate. Fuel gauge reads below E and if I turn the engine over for more than a few seconds my oil pressure gauge rises.
I figured it was a fuel and pump issue until I replaced the pump and did not hear it cycle. I checked voltage at the connector at the pump when the key was cycled and there was no voltage. I replaced the FP relay and every fuse is getting power with all the fuses pins intact in the fuse block.
I sprayed some ether into the intake and cranked it over and no start or fire. I checked a plug wire and confirmed there was no spark to the plugs either. Ignition relay was swapped/checked and no change.
I have not attempted to start it with my extra key and will try that later this afternoon.
12-19-2014, 12:37 PM
#13
you might be doing what compton said,
the electrical system is pretty simple in that everything is relay controlled by the PCM or BCM. a circuit in the PCM/BCM connects a relay such as the fuel pump one to ground which then sends power to the fuel pump. same thing for ignition, and each coil has a wire going to the pcm which is the grounding circuit to fire the coils.
If it were VATS, you would not be able to crank the engine but you can. don't bother with your extra key.
and with the fuel pump replacement not to pour salt in the wound but you should've properly checked your old one installed before the possibly wasted money/time replacing it. if you don't see power at the pump with a meter that's one thing, but you need to jump the fuel pump relay and take the PCM/BCM out of the scenario. Power to the pump and it will run, if it does then you don't replace it until you have some other valid reason.
just because someone can 'tune' does not mean they are any good at it, or even know what they are doing. and with computer programming it is far easier to screw up than get it right. you might not be getting any DTC when you should because a hack programmer modified the PCM in such a way to get your new motor combo working at any cost, disabling rear o2's, emissions stuff that now isn't there, and so on. so unfortunately you might be at the mercy of the tuner. but being a motor/trans replacement and it cranks but not run i think it's more likely someone did a poor job of wiring and you have a broken wire/connector/connection somewhere. and then with the fuel pump not kicking on and coils not firing... if you are correct about that... seems to indicate the PCM/BCM is purposely doing that because that's what controls them.
"chrysler" kid telling me about GM vehicles... kinda funny.
the electrical system is pretty simple in that everything is relay controlled by the PCM or BCM. a circuit in the PCM/BCM connects a relay such as the fuel pump one to ground which then sends power to the fuel pump. same thing for ignition, and each coil has a wire going to the pcm which is the grounding circuit to fire the coils.
If it were VATS, you would not be able to crank the engine but you can. don't bother with your extra key.
and with the fuel pump replacement not to pour salt in the wound but you should've properly checked your old one installed before the possibly wasted money/time replacing it. if you don't see power at the pump with a meter that's one thing, but you need to jump the fuel pump relay and take the PCM/BCM out of the scenario. Power to the pump and it will run, if it does then you don't replace it until you have some other valid reason.
just because someone can 'tune' does not mean they are any good at it, or even know what they are doing. and with computer programming it is far easier to screw up than get it right. you might not be getting any DTC when you should because a hack programmer modified the PCM in such a way to get your new motor combo working at any cost, disabling rear o2's, emissions stuff that now isn't there, and so on. so unfortunately you might be at the mercy of the tuner. but being a motor/trans replacement and it cranks but not run i think it's more likely someone did a poor job of wiring and you have a broken wire/connector/connection somewhere. and then with the fuel pump not kicking on and coils not firing... if you are correct about that... seems to indicate the PCM/BCM is purposely doing that because that's what controls them.
"chrysler" kid telling me about GM vehicles... kinda funny.
12-20-2014, 11:00 AM
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I realize I went to one of the most expensive problems first but the way it was dying out made me think it was a low fuel and then fuel pump issue. I'll jump the fuel relay and watch the tach, I didn't consider the crank sensor but that could definitely be it.
12-22-2014, 11:14 PM
#18
WRONGGGGGG with a long G 1 FMF gave you the correct info.
I'm going to tell you the 1st thing you need to do. 1st find whom ever constructed the car to get a complete picture of what it is you are exactly working on. Year, mods, if it has VATS etc then post up the year and system mods THEN someone can help you.
How can anyone help you if you don't eat yer meat? you can't have a running car if you don't eat yer meat.
I'm going to tell you the 1st thing you need to do. 1st find whom ever constructed the car to get a complete picture of what it is you are exactly working on. Year, mods, if it has VATS etc then post up the year and system mods THEN someone can help you.
How can anyone help you if you don't eat yer meat? you can't have a running car if you don't eat yer meat.
I was wrong because I corrected a guy with a chevelle about the difference between vats on a truck and vats on an fbody?
FMF I never said anything about your post.
Is the security light illuminated? Vats will not throw power to the starter if so. If the starter is turning over it is something else related to both fuel and ignition
Last edited by chrysler kid; 12-22-2014 at 11:22 PM.