WHY???
out of the blue it wont start i tried all new msq files and that didnt work so when I reverted back to my original, it wont start anymore! I have killed my battery many times now trying to start it I am just LOST. And quite frustrated right now.
Anyone in folsom, ca wanna come take a look at it? maybe I have no clue what I am doing, i have between 5-7ms of pulsewidth while cranking and I dont get poop except maybe a hickup every few cranks of it trying to start. I have 50# injectors on a chevy 383.
car wont start
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: car wont start
yes i have spark and I just changed my spark plugs, they were really fouled. I just changed them out with some fresh ac delcos, and I am going to follow this new method for getting my car running from very little fuel to running. wish me luck now I am calmed down.
I've described this before.. maybe in a PM to someone.
On an unknown machine I usually start out with zeroing or lowering req-fuel to ridiculously low values so that the engine can't possibly run on the VE map values once started (= no fuel). Then I increase the priming pulse from 1.0 ms and up until the engine sputters to life and then dies (this should last only one revolution). Then I set the cranking pulsewidth hot and cold values to 1.0 ms and increase them until it makes a significant difference in that it will bring the engine above the cranking rpm (check this setting out! 300 rpm is good).
Starting at 1.0 ms comes from the fact that I've usually started engines with very big injectors, these can push bucket loads of fuel if you're not experienced/careful.
This is where req-fuel and the VE map takes over. On turbocharged machines I set the VE load sites to about 40% so that the values won't go through the roof at x bar boost and max rpm. N/A can use larger values so that you can use the full spectrum 0-255 of % in the load sites for just 0-100 kPa.
After that I increase req-fuel and crank the engine, if it doesn't stay alive I raise req-fuel some more until the engine starts to stay alive by itself. I then increase fuel until I've achieved the best vacuum I can get because this is an indication of a strong engine at idle. You have to adjust the idle air supply enough to keep it at your desired idle rpm (800-1000 rpm usually) while you do this. Only use the pedal to recover the rpm if it slows down too much while you tune.
Remember that the fuel enrichments are active at this point, mainly cold start. You have to adjust your req-fuel again when you've warmed up the engine because you've probably given it more/less than it should have depending on your cold start enrichment bins - they should be adjusted with a cold engine only after you've got the _warm_ engine running well, at least on low loads.
Afterstart enrichment is very tricky, on engines with nice stock cams I never see the point of using it but I've clearly seen problems with hotter cams where you need to play with this.
Understanding all of these parameters are pretty straightforward to me, so I don't rely on any calculations to give me the theoretical values (they're always off) and I find it just as fast to find the right values by hands on experimenting. The key is to try to _never_ give the engine too much fuel at this initial start or you may foul the plugs and nothing will make sense.
Oh BTW.. these tips apply to MegaSquirt and another ECU board, they work the same way and currently use the same tuning software (MegaTune).
I've described this before.. maybe in a PM to someone.
On an unknown machine I usually start out with zeroing or lowering req-fuel to ridiculously low values so that the engine can't possibly run on the VE map values once started (= no fuel). Then I increase the priming pulse from 1.0 ms and up until the engine sputters to life and then dies (this should last only one revolution). Then I set the cranking pulsewidth hot and cold values to 1.0 ms and increase them until it makes a significant difference in that it will bring the engine above the cranking rpm (check this setting out! 300 rpm is good).
Starting at 1.0 ms comes from the fact that I've usually started engines with very big injectors, these can push bucket loads of fuel if you're not experienced/careful.
This is where req-fuel and the VE map takes over. On turbocharged machines I set the VE load sites to about 40% so that the values won't go through the roof at x bar boost and max rpm. N/A can use larger values so that you can use the full spectrum 0-255 of % in the load sites for just 0-100 kPa.
After that I increase req-fuel and crank the engine, if it doesn't stay alive I raise req-fuel some more until the engine starts to stay alive by itself. I then increase fuel until I've achieved the best vacuum I can get because this is an indication of a strong engine at idle. You have to adjust the idle air supply enough to keep it at your desired idle rpm (800-1000 rpm usually) while you do this. Only use the pedal to recover the rpm if it slows down too much while you tune.
Remember that the fuel enrichments are active at this point, mainly cold start. You have to adjust your req-fuel again when you've warmed up the engine because you've probably given it more/less than it should have depending on your cold start enrichment bins - they should be adjusted with a cold engine only after you've got the _warm_ engine running well, at least on low loads.
Afterstart enrichment is very tricky, on engines with nice stock cams I never see the point of using it but I've clearly seen problems with hotter cams where you need to play with this.
Understanding all of these parameters are pretty straightforward to me, so I don't rely on any calculations to give me the theoretical values (they're always off) and I find it just as fast to find the right values by hands on experimenting. The key is to try to _never_ give the engine too much fuel at this initial start or you may foul the plugs and nothing will make sense.
Oh BTW.. these tips apply to MegaSquirt and another ECU board, they work the same way and currently use the same tuning software (MegaTune).
-
MegaDave
- MegaSquirt Newbie
- Posts: 7
- Joined: Thu Jul 15, 2004 5:51 pm
- Location: LA LA land, Southern California
Re: car wont start
Good tips, so does this mean you have yours running good again?
Re: car wont start
yes thank you I went out and did as outlined above, worked well! my prime at 60degrees is only 1ms, and cranking pw is also only 1ms, and my req_fuel bumped up to 30 before it stayed running.
now I need to fudge with the VE tables to get cruising good.
(i need a wideband)
once the car was warmed up (160+) it takes a while of cranking before it fires up but after about 4-5 seconds cranking it fires right up, does this sound like it needs more or less cranking pw ? right now im doing the two point table, and both -40 and 160 are set to 1ms. should I lower my 160 to maybe half a millisecond? or does it sound like it needs more fuel under hot cranking??
now I need to fudge with the VE tables to get cruising good.
(i need a wideband)
once the car was warmed up (160+) it takes a while of cranking before it fires up but after about 4-5 seconds cranking it fires right up, does this sound like it needs more or less cranking pw ? right now im doing the two point table, and both -40 and 160 are set to 1ms. should I lower my 160 to maybe half a millisecond? or does it sound like it needs more fuel under hot cranking??
cold cranking just fine, hot cranking way to long.
Im using the two point table and my -40 degree and my 160 degree cranking pw is both only 2ms, but in my cool california night weather around 50-60 degrees, it fires up fine but once the engine is warmed up (160) it cranks for about 3-4 seconds before it fires. what Can I do?
Re: car wont start
If you hold the peddle down some will it fire faster (too rich)? Look for black smoke, otherwise maybe a richer priming pulse.
Re: car wont start
no smoke whatsoever while cranking or startup, should i richen up the prime pulse under hot? I am going to give it a try. ill let you know tomorrow.
Re: car wont start
Yes. It seems to need a little more fuel than it has. Ether priming pulse or hot cranking pulse modulation. priming pulse is like pushing the gas peddle down on a carb before cranking engine. I'm not in favor of that method in your case so I'd first play with the hot cranking pulse widths. I let mine run out of fuel upon engine shutdown so I get to use a high priming pulse.