NEED HELP! Hilborn fuel injection

[Mathi]

Hi,

I have a Z502 Chevrolet crated engine with a Hilborn fuel injection system on it. It's an electronic fuel injection with Fast ECU and other electric parts.
Now, the injection works perfect only if you stop throttle, there is some bangings in the exhaust . Everytime we stop throttle, there are those annoying bangings. Really loud.
Just like too much fuel...
Now, we tried everything... We contacted Hilborn and they helped us out with some instructions but it was worse after those instructions.

Now, I live in Belgium and we don't know anymore what we can do. We are far away with a system that doesn't work as it should. We have contacted here in our country, the Netherlands, Germany, etc fuel injection specialist but nobody knows this system good enough to help us out.

Can someone help me out?

Thank you!

This fuel injection system:


http://www.hilborninjection.com/prod...=429&CatId=174 (http://www.hilborninjection.com/product.asp?Id=429&CatId=174)

[David Pozzi]

Try the FAST support forum here: http://www.cpgnation.com/forum/tech-support-forums.html
Make sure you don't have an exhaust leak, air entering can cause popping, plus ruin the 02 sensor readings.
With any multi-throttle system, it's very important to balance the throttles so they flow exactly the same amount of air at idle and just off idle. Have you balanced the linkage?
Use a tool like this assuming it is adjustable. http://store.edelbrock.com/4025uni-synafor1and2barrelcarbs.aspx

[MrForce]

1) You should upgrade to the 2.0 software that has a self-tuning feature. They can email the file to you.
2) Have you checked to see if your timing is accurate, check laptop readout to actual on balancer.
3) Use an airflow meter to check flow into each stack.

Rob

[fordsbyjay]

Did you ever get your system sorted out? In Jan. I was at a Big Block Ford Tech seminar and one of the speakers was Jon Kaase from Jon Kaase Racing Engines. He makes his own Boss 9 stack efi system like yours (only better cuz it's for a Ford, LOL JK). A couple things in your post set my memory off about what Jon said.

1st he said that stack efi owner complain about the wierd exhaust note that these systems make. I didn't know what he meant or of if that is the same thing you are experiencing but it is weirdly coincidental.

I checked your link and had a look at your manifold. The black lines I am assuming are to equalize the 8 individual runners?? They are way too small according to Jon. They started small like that and kept making them larger till the engines ran better and the crazy noise went away. How big? His holes are around 1/2" ID.

Look at the link for the Kinsler BBF setup. See how large their tubes are connected to each runner?
http://www.kinsler.com/NewProducts/PDF/SCJweb.pdf

Jon's site is here.
http://www.jonkaaseracingengines.com/

Here is Jon's Boss 429 intake.
http://www.jonkaaseracingengines.com/component/content/article/197-new-products.html
https://static1.pt-content.com/images/noimg.gif

Another page I just found.
http://www.jonkaaseracingengines.com/index.php?option=com_content&view=article&id=229
https://static1.pt-content.com/images/noimg.gif

Jon's intake has an entire plenum area below the intake to join all the runners together. He had some pictures of other manifolds he has converted to a similar setup.

Even though they are Ford guys I would give them a call and see if they can offer some advice.

Good luck.