Startup on Incline
12-16-2016, 05:56 PM
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Startup on Incline
Hope everyone is gearing up for a fun holiday season. I have an odd situation I was hoping somebody might be able to shed some light on. I have a 99 Boxster. Never had any issues starting/firing up...until this week. I had to switch spots where I park it during the day (at work) and it's a bit of an incline.
-On the first day, I was running low on gas (maybe 40 miles left), so when I got back to the car, it was turning over, but not firing. I figured maybe it's so low on gas that the incline is coming into play/maybe something is not reaching an area where it should. So I put the car in neutral, rolled back to a level surface and it started. Went to fill it up with gas, drove it around, turned it off and on again at many points, no problem.
-Next day, parking in the same spot - this time with gas - it won't fire. Turns over but won't start up. So I thought - OK, something is wrong. There was a mechanic right next door, so I explained it to him, he said probably the fuel pump. So I gave him the key with the idea that he'd work on it in the next day or two. He calls me back the next day and said the car fires up fine; very smoothly. Very unlikely to be the fuel pump. He says drive it until something definitively breaks.
-Last night, drove it multiple times - no problem. Today, same thing happens. Parked on the incline - actually this time I reversed into the spot, so parked in a decline - and it won't start. Then I popped it in neutral and leveled it out, and after waiting for five minutes, it started up again.
Does anyone have any idea what this might be? The mechanic said it could be Costco gas; they don't have additive and he said 9/10 cars that have this type of issue fill up on Costco gas. He also said some Sea Foam might cure the problem, but hard to say without diagnostic.
Anyone have a clue/tip/hint? Would be greatly appreciated. Car starts perfectly fine when it's parked on a flat surface.
-On the first day, I was running low on gas (maybe 40 miles left), so when I got back to the car, it was turning over, but not firing. I figured maybe it's so low on gas that the incline is coming into play/maybe something is not reaching an area where it should. So I put the car in neutral, rolled back to a level surface and it started. Went to fill it up with gas, drove it around, turned it off and on again at many points, no problem.
-Next day, parking in the same spot - this time with gas - it won't fire. Turns over but won't start up. So I thought - OK, something is wrong. There was a mechanic right next door, so I explained it to him, he said probably the fuel pump. So I gave him the key with the idea that he'd work on it in the next day or two. He calls me back the next day and said the car fires up fine; very smoothly. Very unlikely to be the fuel pump. He says drive it until something definitively breaks.
-Last night, drove it multiple times - no problem. Today, same thing happens. Parked on the incline - actually this time I reversed into the spot, so parked in a decline - and it won't start. Then I popped it in neutral and leveled it out, and after waiting for five minutes, it started up again.
Does anyone have any idea what this might be? The mechanic said it could be Costco gas; they don't have additive and he said 9/10 cars that have this type of issue fill up on Costco gas. He also said some Sea Foam might cure the problem, but hard to say without diagnostic.
Anyone have a clue/tip/hint? Would be greatly appreciated. Car starts perfectly fine when it's parked on a flat surface.
12-16-2016, 06:14 PM
#2
Race Director
Hope everyone is gearing up for a fun holiday season. I have an odd situation I was hoping somebody might be able to shed some light on. I have a 99 Boxster. Never had any issues starting/firing up...until this week. I had to switch spots where I park it during the day (at work) and it's a bit of an incline.
-On the first day, I was running low on gas (maybe 40 miles left), so when I got back to the car, it was turning over, but not firing. I figured maybe it's so low on gas that the incline is coming into play/maybe something is not reaching an area where it should. So I put the car in neutral, rolled back to a level surface and it started. Went to fill it up with gas, drove it around, turned it off and on again at many points, no problem.
-Next day, parking in the same spot - this time with gas - it won't fire. Turns over but won't start up. So I thought - OK, something is wrong. There was a mechanic right next door, so I explained it to him, he said probably the fuel pump. So I gave him the key with the idea that he'd work on it in the next day or two. He calls me back the next day and said the car fires up fine; very smoothly. Very unlikely to be the fuel pump. He says drive it until something definitively breaks.
-Last night, drove it multiple times - no problem. Today, same thing happens. Parked on the incline - actually this time I reversed into the spot, so parked in a decline - and it won't start. Then I popped it in neutral and leveled it out, and after waiting for five minutes, it started up again.
Does anyone have any idea what this might be? The mechanic said it could be Costco gas; they don't have additive and he said 9/10 cars that have this type of issue fill up on Costco gas. He also said some Sea Foam might cure the problem, but hard to say without diagnostic.
Anyone have a clue/tip/hint? Would be greatly appreciated. Car starts perfectly fine when it's parked on a flat surface.
-On the first day, I was running low on gas (maybe 40 miles left), so when I got back to the car, it was turning over, but not firing. I figured maybe it's so low on gas that the incline is coming into play/maybe something is not reaching an area where it should. So I put the car in neutral, rolled back to a level surface and it started. Went to fill it up with gas, drove it around, turned it off and on again at many points, no problem.
-Next day, parking in the same spot - this time with gas - it won't fire. Turns over but won't start up. So I thought - OK, something is wrong. There was a mechanic right next door, so I explained it to him, he said probably the fuel pump. So I gave him the key with the idea that he'd work on it in the next day or two. He calls me back the next day and said the car fires up fine; very smoothly. Very unlikely to be the fuel pump. He says drive it until something definitively breaks.
-Last night, drove it multiple times - no problem. Today, same thing happens. Parked on the incline - actually this time I reversed into the spot, so parked in a decline - and it won't start. Then I popped it in neutral and leveled it out, and after waiting for five minutes, it started up again.
Does anyone have any idea what this might be? The mechanic said it could be Costco gas; they don't have additive and he said 9/10 cars that have this type of issue fill up on Costco gas. He also said some Sea Foam might cure the problem, but hard to say without diagnostic.
Anyone have a clue/tip/hint? Would be greatly appreciated. Car starts perfectly fine when it's parked on a flat surface.
More than likely the starting behavior is due to an intermittently working fuel pump.
Less likely is there is a crack in a fuel line in the fuel tank and the parking on an incline causes the crack to open up.
One possible "test" for this is if you can safely do this on the incline if you can let the car roll back a bit then hit the brakes pretty hard and try to start the engine. Hitting the brakes pretty hard will jostle the fuel in the tank and the lines and possibly close the crack.
Or start the engine and on a road where you have the room swerve the car sharply side to side like one sees race drivers do when trying to get some heat in the tires. If the engine cuts out or acts up at all this suggests an internal -- in the tank -- fuel leak.
12-16-2016, 06:27 PM
#3
Rennlist Member
I stopped using Costco gas because of issues I was having with my Dodge Ram. Never had the problem since I stopped using it.
Not saying that's your problem but try it and report back.
Not saying that's your problem but try it and report back.
12-16-2016, 06:44 PM
#4
Intermediate
I'll pay the extra cents at any other gas station for convenience.
I typically throw a bottle of SeaFoam in my Tacoma once a quarter.
Never had a problem.
12-16-2016, 06:59 PM
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That would have to be some pretty bad Costco gasoline but in case it is the gasoline fill up with another brand like Chevron or Shell or Union 76 or Philips 66. Any one of those brands I've used a number of times and they are all pretty good though I prefer Chevron for the Techron. (I found after a tank or two of Chevron my Boxster was running better. The only change was switching away from Shell to Chevron driven by the fact the Chevron gasoline was 10 cents a gallon cheaper than the Shell.)
More than likely the starting behavior is due to an intermittently working fuel pump.
Less likely is there is a crack in a fuel line in the fuel tank and the parking on an incline causes the crack to open up.
One possible "test" for this is if you can safely do this on the incline if you can let the car roll back a bit then hit the brakes pretty hard and try to start the engine. Hitting the brakes pretty hard will jostle the fuel in the tank and the lines and possibly close the crack.
Or start the engine and on a road where you have the room swerve the car sharply side to side like one sees race drivers do when trying to get some heat in the tires. If the engine cuts out or acts up at all this suggests an internal -- in the tank -- fuel leak.
More than likely the starting behavior is due to an intermittently working fuel pump.
Less likely is there is a crack in a fuel line in the fuel tank and the parking on an incline causes the crack to open up.
One possible "test" for this is if you can safely do this on the incline if you can let the car roll back a bit then hit the brakes pretty hard and try to start the engine. Hitting the brakes pretty hard will jostle the fuel in the tank and the lines and possibly close the crack.
Or start the engine and on a road where you have the room swerve the car sharply side to side like one sees race drivers do when trying to get some heat in the tires. If the engine cuts out or acts up at all this suggests an internal -- in the tank -- fuel leak.
Why/how would the type of gas impact it in on startup - particularly while on an incline/decline?
12-16-2016, 07:28 PM
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12-16-2016, 08:27 PM
#7
Drifting
So Costco gas is only bad on an incline? And the logic for that diagnosis is....... ?
More likely a weak fuel pump or as suggested loose connections or leaks in the flow or return lines/connections. BTW you may need a new mechanic. Ask here for suggestions for your location.
Also see this:
https://rennlist.com/forums/boxster-...l-fill-up.html
More likely a weak fuel pump or as suggested loose connections or leaks in the flow or return lines/connections. BTW you may need a new mechanic. Ask here for suggestions for your location.
Also see this:
https://rennlist.com/forums/boxster-...l-fill-up.html
Last edited by Schnell Gelb; 12-18-2016 at 04:22 PM.
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12-17-2016, 12:28 PM
#9
Race Director
A EVO car mag (UK car mag) fuel test found "supermarket" gasoline consistently underperforming premium brand gasolines. Since "supermarket" stations rely upon price to attract customers one often gets what one pays for. Cheap gasoline.
If there is some stratification going on it would occur regardless of whether the car was level or parked on an incline.
The behavior is much more likely to be a fuel supply/pressure problem and not a fuel quality problem.
I forgot to mention it before but there could be an issue with the crankshaft position sensor. It could be loose (or intermittently bad) though I like loose given the behavior occurs only on an incline and the DME doesn't receive any crankshaft position signal so it can't know when to trigger a fuel injector pulse or a spark.
I agree with Schnell Gelb that you need a new mechanic if the best he came come up with Costco gas is to blame.
12-17-2016, 02:04 PM
#10
Burning Brakes
There may be a difference in gas measured over many tanks and due to the different additive packages that get added. But all the gas comes up through the same pipeline to the tanks. Hundreds of thousands of people use non-branded or supermarket gas successfully. I do and have for years. Provided the car is stock and has no performance mods, the car should start even if you have regular from the cheapest station in your state. Run well is another story.
So look for another explanation. Test the fuel pressure. Look at the CPS. You know you have a good ignition switch and the starter turns the car over. So what if left is fuel delivery or the CPS signal that says pulse that fuel.
If you say where you are, someone may be able to suggest an experienced Porsche mechanic local to you.
So look for another explanation. Test the fuel pressure. Look at the CPS. You know you have a good ignition switch and the starter turns the car over. So what if left is fuel delivery or the CPS signal that says pulse that fuel.
If you say where you are, someone may be able to suggest an experienced Porsche mechanic local to you.
12-17-2016, 02:41 PM
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Thanks guys. I am in Scottsdale, so if you have a suggestion for a good mechanic, that would be great (North Scottsdale).
No I don't blame this mechanic. I left the car for him and he was going to have to push it across the parking lot to get to his garage to do the diagnostic, etc. When I showed him the car (when I the had the issue), he guessed fuel pump. He wasn't able to inspect the car at that time, so I left it in the parking lot. When he came back to push it over to his garage the next day, the car fired up just fine, so he called me and gave me the option to do the diagnostic or to leave it until something is for sure broken (to save cost for now). So that's what I opted for because I had never had this problem.
One other note: is it possible I harmed the fuel pump when I was on low? So if the gas tank is near empty and I'm on the incline, trying to start but it's not firing up, can I harm the fuel pump by continuously trying? I didn't do it for long, but wondering if that can harm the fuel pump.
No I don't blame this mechanic. I left the car for him and he was going to have to push it across the parking lot to get to his garage to do the diagnostic, etc. When I showed him the car (when I the had the issue), he guessed fuel pump. He wasn't able to inspect the car at that time, so I left it in the parking lot. When he came back to push it over to his garage the next day, the car fired up just fine, so he called me and gave me the option to do the diagnostic or to leave it until something is for sure broken (to save cost for now). So that's what I opted for because I had never had this problem.
One other note: is it possible I harmed the fuel pump when I was on low? So if the gas tank is near empty and I'm on the incline, trying to start but it's not firing up, can I harm the fuel pump by continuously trying? I didn't do it for long, but wondering if that can harm the fuel pump.
12-17-2016, 05:25 PM
#12
Drifting
Just get some proper diagnostics done. The keyboard stuff is not helping.
1.Standard test for fuel pressure at the fuel pressure regulator next time it misbehaves (rear/front up up on ramps?) And test the fuel pressure regulator while you are there? Awful job because of access around Bank 2 , #4
2. Is old or water contaminated fuel a possibility ? Fuel Contamination fixes is another whole Thread.
If the fuel pump is R&R for testing that is a battery out job so all the precautions apply.
Suggest you read here for Modes of failure for the pump so you know what to expect.Lets hope it is O.K.? If the fuel filter has not been changed in the last 30k, that may be an additional?
1.Standard test for fuel pressure at the fuel pressure regulator next time it misbehaves (rear/front up up on ramps?) And test the fuel pressure regulator while you are there? Awful job because of access around Bank 2 , #4
2. Is old or water contaminated fuel a possibility ? Fuel Contamination fixes is another whole Thread.
If the fuel pump is R&R for testing that is a battery out job so all the precautions apply.
Suggest you read here for Modes of failure for the pump so you know what to expect.Lets hope it is O.K.? If the fuel filter has not been changed in the last 30k, that may be an additional?
12-17-2016, 11:09 PM
#13
Ummmm...no, no and no. The fuel suggestions are a wild goose chase.
This is clearly a problem with the EVAP system (probably tank vent, but check it all). It's in the owners manual (pg 123) and specifically mentions parking on an incline.
The charcoal canister stores fumes from the gas tank and feeds them into the intake manifold to be burned when the car is running to prevent the fumes from escaping into the atmosphere. The fumes leave the tank through the vent line and pass through a check valve into the canister. I suspect that valve is bad, but the whole system should be checked.
I guarantee that this is your issue. I will put money it.
This is clearly a problem with the EVAP system (probably tank vent, but check it all). It's in the owners manual (pg 123) and specifically mentions parking on an incline.
The charcoal canister stores fumes from the gas tank and feeds them into the intake manifold to be burned when the car is running to prevent the fumes from escaping into the atmosphere. The fumes leave the tank through the vent line and pass through a check valve into the canister. I suspect that valve is bad, but the whole system should be checked.
I guarantee that this is your issue. I will put money it.
12-17-2016, 11:27 PM
#14
Race Director
Ummmm...no, no and no. The fuel suggestions are a wild goose chase.
This is clearly a problem with the EVAP system (probably tank vent, but check it all). It's in the owners manual (pg 123) and specifically mentions parking on an incline.
I guarantee that this is your issue. I will put money it.
This is clearly a problem with the EVAP system (probably tank vent, but check it all). It's in the owners manual (pg 123) and specifically mentions parking on an incline.
I guarantee that this is your issue. I will put money it.
Let me see if I can find that...
To the OP: I think this the thread:
https://rennlist.com/forums/boxster-...l#post13814781
However in quickly scanning through the posts it is not quite the same. The engine did't want to start after a fuel tank fill up and there was a CEL with a number of error codes.
However with nothing other than no start on an incline and no CEL and error codes I am not ready to dismiss a fuel supply/pressure problem.
12-17-2016, 11:34 PM
#15
Race Director
Thanks guys. I am in Scottsdale, so if you have a suggestion for a good mechanic, that would be great (North Scottsdale).
No I don't blame this mechanic. I left the car for him and he was going to have to push it across the parking lot to get to his garage to do the diagnostic, etc. When I showed him the car (when I the had the issue), he guessed fuel pump. He wasn't able to inspect the car at that time, so I left it in the parking lot. When he came back to push it over to his garage the next day, the car fired up just fine, so he called me and gave me the option to do the diagnostic or to leave it until something is for sure broken (to save cost for now). So that's what I opted for because I had never had this problem.
One other note: is it possible I harmed the fuel pump when I was on low? So if the gas tank is near empty and I'm on the incline, trying to start but it's not firing up, can I harm the fuel pump by continuously trying? I didn't do it for long, but wondering if that can harm the fuel pump.
No I don't blame this mechanic. I left the car for him and he was going to have to push it across the parking lot to get to his garage to do the diagnostic, etc. When I showed him the car (when I the had the issue), he guessed fuel pump. He wasn't able to inspect the car at that time, so I left it in the parking lot. When he came back to push it over to his garage the next day, the car fired up just fine, so he called me and gave me the option to do the diagnostic or to leave it until something is for sure broken (to save cost for now). So that's what I opted for because I had never had this problem.
One other note: is it possible I harmed the fuel pump when I was on low? So if the gas tank is near empty and I'm on the incline, trying to start but it's not firing up, can I harm the fuel pump by continuously trying? I didn't do it for long, but wondering if that can harm the fuel pump.
You did not harm the fuel pump. If it is running -- and of course it is suspected of not running and this accounts for the no start behavior -- it won't get hot enough to harm the thing. It is submerged in fuel and part of the pump's output is directed to cause fuel to circulate fuel around the pump -- in its plastic enclosure -- so the pump stays cool, cooled by the fuel.
What one can do is run down the battery -- remember it takes some drive time to recharge the battery after a successful start and unsuccessful ones really hammer the battery -- or overheat the starter motor.