Hi,
I am new to the forum and also a first time user of the MegaSquirt kit which I intend to fit on to a single cylinder 350 engine.
I would want to get more information on the timing for the fuel injection and here is my understanding so far:
The fuel pulse width calculation takes in to account the signal obtained from the tach (rather ignition coil) to know when to squirt the fuel.
In actuality, the signal obtained from the ignition coil is for the spark when the piston is at TDC. So, when the fuel is squirt, it will have to wait for a substantial amount of time before it is taken in to the engine in the next cycle.
This will cause most of the fuel to go waste because of evaporation when the engine is hot and will increase the fuel consumption.
Will it be a good addition to have a sensor to know the point at which the intake valve opens and feed it as the signal, instead of the one currently being used from the tach?
Looking forward to hear the views of the forum.
-Prabhakar
Injector timing on single cylinder engines
Forum rules
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).
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.
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).
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.
-
jonnaprabhu
- MegaSquirt Newbie
- Posts: 1
- Joined: Wed Aug 01, 2012 1:14 am
-
Bernard Fife
- Master Squirter
- Posts: 475
- Joined: Thu Oct 29, 2009 12:54 pm
Re: Injector timing on single cylinder engines
jon,
That is wrong. The fuel just sits there at the valve evaporating and goes in the cylinder on the very next intake cycle (which is not a substantial amount of time). The fuel doesn't move far because the air doesn't move (because the valve is closed). The fuel won't burn until it evaporates, so that is a good thing. OEM FI typically injects against a closed hot intake valve exactly for that reason. Also, see this: http://www.megamanual.com/MSFAQ.htm#sequential
Lance.
That is wrong. The fuel just sits there at the valve evaporating and goes in the cylinder on the very next intake cycle (which is not a substantial amount of time). The fuel doesn't move far because the air doesn't move (because the valve is closed). The fuel won't burn until it evaporates, so that is a good thing. OEM FI typically injects against a closed hot intake valve exactly for that reason. Also, see this: http://www.megamanual.com/MSFAQ.htm#sequential
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw