yoeddynz

DIY Fuel injection thread.

Recommended Posts

A fellow hairdresser has offered the use of his syncrometer so I'll pick that up whenever i can.  Currently running with 16v throttles although I have a set of blacktops in storage. Seems like the adjustment will be much the same.  Not looking forward to doing that on the car though.

The map sensor i had hooked up as I was going to try run the megasqsuirt "ITB" mode, which uses speed density close to idle, then has a changover point for alpha-n.  Based on the quick drive around the block I did before noticing the misfire, its probably not needed as it felt drivable down low as is.    And yes I can use the exisitng map sensor for baro correection.

I'll cap off the vacuum on the fuel pressure reg.  Its not something i thought about but what you say makes sense.     Cheers for the advice, hopefully can have it sorted soon enough.

Share this post


Link to post
Share on other sites

Yeah can get good results in alpha n only.   Only benifit using  map at idle would  be so you can run an air bypass for idle control. 

Share this post


Link to post
Share on other sites

Hi everyone, first time poster in the injection thread (read it a lot tho) just got a question about a fpr in my mazda. I think its seized, should I be able to move the return valve by pressing it? I can apply about 25hg of vacuum to it but nothing seems to move. With zero vacuum applied so should there be any flow from the regulator at all? I can blow Tiny amount of air through it.. Cheers

Share this post


Link to post
Share on other sites

Can you measure fuel pressure? Easiest way is to see what base pressure is with no vacuum and then when manually applying vacuum see if the pressure increases. If it doesn't increase then its poked. There should be specs on what fuel pressure should be at certain vacuum levels. 

Share this post


Link to post
Share on other sites

If it's a bosch based efi system it will probably run 3 bar fuel pressure and drop at pretty much 1:1 with the manifold pressure, so like 2.3 bar at idle.

Since you are running an aftermarket ECU you should be able to get away with just disconnecting the vacuum source from the regulator and running at fixed pressure and tune for that. A simple inline fuel gauge should do the job.

Are you using a wideband oxy sensor?

You were posting about it pulsing or something at idle? That is often an indication of your AFR being wrong so it swings between too rich and too lean

 

You also mentioned your temperature sensor was all over the place. Fueling changes significantly with temperature readings, so this could be the cause of your issues.

  • Like 1

Share this post


Link to post
Share on other sites

reg isnt going to move with vacuum on it alone.       standard  43psi fuel pressure reg will need round abouts 43psi before it allows fuel to bypass.       so if  had 43psi fuel pressure, then added vacuum to the top side it would start to move more, to allow more fuel to bypass and drop the fuel pressure  by how ever much vac added to the top

if you could put negative 43psi on the reg with zero fuel pressure it would move.  but yeh that much vac isn't possible

Also,  always use the vac line. unless its a NA itb setup

Share this post


Link to post
Share on other sites
2 hours ago, ajg193 said:

If it's a bosch based efi system it will probably run 3 bar fuel pressure and drop at pretty much 1:1 with the manifold pressure, so like 2.3 bar at idle.

Since you are running an aftermarket ECU you should be able to get away with just disconnecting the vacuum source from the regulator and running at fixed pressure and tune for that. A simple inline fuel gauge should do the job.

Are you using a wideband oxy sensor?

You were posting about it pulsing or something at idle? That is often an indication of your AFR being wrong so it swings between too rich and too lean

 

You also mentioned your temperature sensor was all over the place. Fueling changes significantly with temperature readings, so this could be the cause of your issues.

 

 

Yeah there are other issues I need to sort, but this is the main problem. The surging at idle is caused by the fuel pump cavitating as is completely in sync with the noise's the pump makes as it gets hot and vaporises fuel.. When I plumb the feed straight to the return there's no restriction for the pump and it doesn't get remotely warm. As soon as I go back through the fuel rail it gets hot and surges at idle.. Surely that's the regulator as its the only restriction.. Might need to bail back out to pick apart and get another reg.. 

Share this post


Link to post
Share on other sites
2 hours ago, ajg193 said:

If it's a bosch based efi system it will probably run 3 bar fuel pressure and drop at pretty much 1:1 with the manifold pressure, so like 2.3 bar at idle.

Since you are running an aftermarket ECU you should be able to get away with just disconnecting the vacuum source from the regulator and running at fixed pressure and tune for that. A simple inline fuel gauge should do the job.

Are you using a wideband oxy sensor?

You were posting about it pulsing or something at idle? That is often an indication of your AFR being wrong so it swings between too rich and too lean

 

You also mentioned your temperature sensor was all over the place. Fueling changes significantly with temperature readings, so this could be the cause of your issues.

 

 

Yeah there are other issues I need to sort, but this is the main problem. The surging at idle is caused by the fuel pump cavitating as is completely in sync with the noise's the pump makes as it gets hot and vaporises fuel.. When I plumb the feed straight to the return there's no restriction for the pump and it doesn't get remotely warm. As soon as I go back through the fuel rail it gets hot and surges at idle.. Surely that's the regulator as its the only restriction.. Might need to bail back out to pick apart and get another reg.. 

Share this post


Link to post
Share on other sites

Ok, so now I've discovered my fpr's seem better days, I guess I'm after a new one. What brand is reliable and cost effective? Was looking at a turbosmart fpr800 off the tard, or are there better options? Cheers

Share this post


Link to post
Share on other sites

There's a full efi conversion kit for single cyl engines 100cc to 400cc bout 1k

Also saw an old thread of a guy using a megasquirt for a bit cheaper.

There's a throttle body unit from a Suzuki 125 on TradeMe now for a hundy. Could mash a speeduino on that and be done pretty cheap

 

I worked out how many Kms it would take to pay itself off. Only 10 times around the clock...

 

 

 

Same kit but $430

https://www.ebay.com/itm/motorcycle-ATV-scooter-buggy-moped-UAV-EFI-engine-Electronic-Fuel-Injection-kit/273127447029?hash=item3f97aa19f5:g:PHwAAOSwaudbUUTp

Only 5 times round the clock for that

Share this post


Link to post
Share on other sites

The Link G4X has landed!

 

Only Atom and Monsoon versions for now. But some cool new features.

1000hz logging with more onboard memory.

Math channels so you can create new variables which can be used as a load axis or switch trigger or whatever.

Proper MAF support.

And a few other cool bits.

Might get a Storm when they come out / fixed first few rounds of firmware haha

  • Like 5

Share this post


Link to post
Share on other sites

I've been working on a new loom. 

Bought a bunch of thin wall TXL wire from the states. Really nice to work with! 

Using all 20 gauge except for where heavier is needed. But now kinda wish I went to 22 for the sensor wires. As it's all still quite a big bundle.

Also it's considerably easier and quicker to actually make a loom from scratch, because you can just pin and lay out bundles of wires as you go, then look what outputs you have left and then see where's a nice place to put the next one. Rather than dealing with the spaghetti of a full prewired loom.

Gotta say its quite satisfying having decent crimp tools and all of the right connectors plugs etc.

This time around the plan is:
4x coils
4x injectors
4x temp sensors (rad, engine, oil, air)
4x wheel speed sensors
2x vvti solenoids/cam sensors
Bosch Ethrottle
Cruise control
Map sensor (for fuel pressure differential calcs)
Maf sensor (For main load source)
Knock sensor
Fuel pressure sensor
Rad fan
Fuel pump
Oil pressure sensor
Purge valve
Starter moror control
Brake & clutch switches

Then some more stuff coming over canbus such as wideband oxy sensor.

Adds up to a big loom pretty quick.
I've scavenged a bunch of the dead end plugs / distribution block type plugs from some factory looms to use for 5v supply / sensor ground / 12v supply. 
Works really nicely because I've got more than 1 plug full of sensor grounds so seems unrealistic to do an open barrel splice for that many wires.
As well as being easy to add/remove things this way.

loom.jpg.d838a27e6b24f91de0006542b5d9eec0.jpg

I've run out of DIs but still plenty of outputs and analog inputs left.

I'm building a new body loom for the car too, so will have just one central fuse box and go outwards from the center console area to everything.

Just trying to decide where to have the breaks in the loom so its removable. 

Currently thinking fuse box and all fused items will be part of the body loom.
Then wheel speed sensor wiring on seperate plugs close to the ECU,
Then all the engine stuff on a single branch or maybe 2 branches into the engine bay.

I've learned a bit from my previous looms but still feels a bit intimidating redoing all of the body wiring.
But then in some ways its actually easier, feels like integrating into an existing loom and figuring it out is always the hardest part.

Half tempted to go DR25 in the engine bay because it looks cool buuuutttttttt makes things really difficult to alter 
(I'm guaranteed to chop and change things later..)

 

  • Like 5

Share this post


Link to post
Share on other sites

You can save space by spinning up the circuits, tightens the loom up a fair bit.  Cheats concentric twist.

16707408_437539579911047_608216860877001

  • Like 4

Share this post


Link to post
Share on other sites

Ahhh cool thanks. 

How many things do you twist together as one? 

Example, coilpack wiring would you twist the 3 wires per coilpack together? 

Or all 4 coilpacks worth of wires

Share this post


Link to post
Share on other sites

Its the same for injectors and coils, but I usually twist the 4x drives and the power feed together through to engine, then split with an open barrel crimp into the 4 individual power feeds and split to each injector/coil from there.  I can't find a photo of the last set of COP's I've done but with smart coils for example I usually slam a plug in there to avoid having to take the whole shooting box out if the engine/loom has to come out, but from there seperate the earths off to the head while the loom shoots back into the cabin.  Many ways to skin the cat I guess.

20597414_526343791030625_502029401337327

  • Like 2

Share this post


Link to post
Share on other sites

Yeah definitely keen to look at idea of some sub-looms to make life easier. 

I'm splitting my headlight wiring down each side of the car so nothing runs across the front anymore.
So dont have to unplug and move wiring in order to get the engine out. 
Just little things that slowly annoy you over years and years of pulling out same motor over and over 

God bless that 3S reliability 

  • Like 1
  • Haha 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.