Forgive me if this has been asked once before. I couldn't find it doing a search.
Now that I have my enigne starting more consistently I've noticed something with the idle. The rpm's seem to change between when the engine is cold and hot.
If I set my idle to 800rpm when the engine is cold, by the time it warms up, the idle has jumped to 1100-1200rpm. If I back my idle stop screw off so that I have 800rpm when the engine is warm I've noticed that when I go to start it cold, it wants to idle at 500rpm and the engine tries to die.
Is there something I'm missing with my tuning that would solve this problem?
Thanks guys!
RPM changes between cold and hot?
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). 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.
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.
RPM changes between cold and hot?
Andrew Geeting
1987 Oldsmobile Cutlass Supreme
455/T-56/4.30 w/ MS EFI
MS-II in a MS-1 version 2.2 board - 2.891 code
1987 Oldsmobile Cutlass Supreme
455/T-56/4.30 w/ MS EFI
MS-II in a MS-1 version 2.2 board - 2.891 code
-
Bernard Fife
- Master Squirter
- Posts: 475
- Joined: Thu Oct 29, 2009 12:54 pm
Re: RPM changes between cold and hot?
Andrew,
If you have an IAC, you need to adjust it to increase the idle speed when cold. If you don't have an IAC, you can 'bandage' this by reducing the ignition advance timing when the engine is warm but keeping it optimal when the engine is cold. How you would do that depends on the code. Which code version are you running?
Lance.
If you have an IAC, you need to adjust it to increase the idle speed when cold. If you don't have an IAC, you can 'bandage' this by reducing the ignition advance timing when the engine is warm but keeping it optimal when the engine is cold. How you would do that depends on the code. Which code version are you running?
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw
Re: RPM changes between cold and hot?
I do have an IAC. Haven't got into figuring it out yet as I was concentrating on just getting the engine started.
My code version is B&G 2.300
Thanks,
My code version is B&G 2.300
Thanks,
Andrew Geeting
1987 Oldsmobile Cutlass Supreme
455/T-56/4.30 w/ MS EFI
MS-II in a MS-1 version 2.2 board - 2.891 code
1987 Oldsmobile Cutlass Supreme
455/T-56/4.30 w/ MS EFI
MS-II in a MS-1 version 2.2 board - 2.891 code
-
Bernard Fife
- Master Squirter
- Posts: 475
- Joined: Thu Oct 29, 2009 12:54 pm
Re: RPM changes between cold and hot?
Andrew,
The IAC adjustments will fix this right up for you, so it looks like you are right at that point of the tuning process. See: http://www.megamanual.com/ms2/tune.htm#idle
Lance.
The IAC adjustments will fix this right up for you, so it looks like you are right at that point of the tuning process. See: http://www.megamanual.com/ms2/tune.htm#idle
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw