I am running 43lb pico (eldelbrock) injectors at 45 lbs of pressure, Having a hard time getting this thing to idle. (rich) I was wondering if turning the pressure down will help? Maybe the injectors are to big?
I have a 462 ci and I was wondering what size injectors and fuel pressure other people that are using Pontiac motors are set up at? Naturally aspirated of coarse.
injectors to large?
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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).
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.
injectors to large?
Multi Port FI Pontiac 462
44 lb low impedance LC1 Wideband O2
MS2 V 3.57 MS2 Extra 3.0.3s TS MS V1.14
44 lb low impedance LC1 Wideband O2
MS2 V 3.57 MS2 Extra 3.0.3s TS MS V1.14
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Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: injectors to large?
The engine may like to idle slightly rich, like 13:1, and this is pretty normal. You should be able to get away with injectors that large; we're running bigger ones on a 1.6 Miata...
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Bernard Fife
- Master Squirter
- Posts: 475
- Joined: Thu Oct 29, 2009 12:54 pm
Re: injectors to large?
Fullhouse,
As Matt correctly says (as always), those injectors should be fine.
Just too add some info, one thing that can cause a too rich idle is having the injector opening time set too long. If you have it set to 1.0, you might try 0.9 or even 0.8. This will require a retune of the VE table around idle conditions, but might give you much more control over the fuel.
Other things that might cause a rich idle include:
- having EGO feedback on and having a rich misfire (the misfire will drive the fuel even richer), make sure EGO control is disabled at idle (most codes have a 'minimum rpm for EGO control' setting - you should make sure it is set at least 200-300 rpm higher than your highest cold idle speed)
- a damaged diaphragm in the fuel pressure regulator (the fuel can be drawn directly into the manifold by the intake vacuum).
If you post a log of the engine at idle, we might be able to comment better.
Lance.
As Matt correctly says (as always), those injectors should be fine.
Just too add some info, one thing that can cause a too rich idle is having the injector opening time set too long. If you have it set to 1.0, you might try 0.9 or even 0.8. This will require a retune of the VE table around idle conditions, but might give you much more control over the fuel.
Other things that might cause a rich idle include:
- having EGO feedback on and having a rich misfire (the misfire will drive the fuel even richer), make sure EGO control is disabled at idle (most codes have a 'minimum rpm for EGO control' setting - you should make sure it is set at least 200-300 rpm higher than your highest cold idle speed)
- a damaged diaphragm in the fuel pressure regulator (the fuel can be drawn directly into the manifold by the intake vacuum).
If you post a log of the engine at idle, we might be able to comment better.
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw