thewird

iTrader: (8)

I've been trying to get a buddies friend car going for some time now. He has a Haltech E8 in a 2nd gen and have been running into fueling issues from the getgo. Since the beginning, we've fixed a multitude of problems. Wiring issues, fuel leaks, turbo coolant leaks, coil firing order traced and connected properly, and timing set correctly as it was retarded by 15 degrees with a timing light.

Anyway basically this is the problem, the car has stock primary 550cc injectors and 1600cc secondary injectors but the car needs 3.5-4ms of injector ontime just to idle. So this becomes a problem since when you actually demand fuel out of the injectors it just leans out even if it pump it up to 8-11ms (vacuum, low RPM).

The first thing I thought of was fuel pressure or injectors themselves. Fuel pressure was verified to be 40 PSi and injectors were cleaned and flow tested and they do flow around 550cc. So at this point I'm starting to think that its the computer itself. In my experience the idle should be around 2ms with these injectors which is why I think something is wrong. Does anyone have any other ideas?

I took a picture while it was idling so you could see what I mean... And the one below it is after the timing was adjusted correctly with a timing light and set the coils up with the correct firing order (notice its pulling more vacuum)...





thewird

Bwek

iTrader: (4)

Also should be noted that the primaries are High Imp S5 t2's and the secondaries are low Imp

and gets a nasty fuel break up around 3-3500 rpm

Sesshoumaru

iTrader: (1)

Check Grounds

Not just the haltech - make sures the motor is grounded to the chasis properly (typically done by the starter bolt).

Check that the battery has good chasis ground and haltech has one good chasis ground also.

When you have multiple grounds you get potential rise and a voltage difference that alot of current can possibly flow through.

I find people tend to take ground too lightly and do it incorrectly causing power loss and signal degradation.



Do some data logging.

What is the voltage when you break up at 3.5k?

What does the MAP do?

What is the trigger doing?

Log the **** out of it.

It's a handy tool.

Bwek

iTrader: (4)

Ill be picking the car up tmw night I'll post the logs for it

Is there a Trigger log for the cas? Double check that for interference I know the Engine harness is a bit of a Cluster F--- so when i grab I'll be redoing the engine harness

Thewird add me on MSN Minimancan@hotmail.com

thewird

iTrader: (8)

^ It breaks up because it goes extremely lean. Related to the same problem on how it requires too much injector ontime just to idle.

Would changing the injector driver settings between 8/5/2 amps have any affect on fuel delivery? I tried all 3 settings and there was never any change on the fuel delivery. I restarted the car every time I changed the settings in case it needed a restart to take affect. We're using 5amps currently because Claudio said that should work fine without the need for resistors with the high/low impedance combo.

thewird

Sesshoumaru

iTrader: (1)

No your fine - the different settings are for driving multiple low imp drivers on a channel (hence why it's channel specific).

5A is plenty since your only driving one injector per channel.

3-4ms on 550cc isn't unheard of for idle and is fairly normal (I think i run 2-3ms on 850cc).

3500 would be your secondaries most likely trying to come online.

RPM + MAP will tell you this if you logged.

If you flipped your secondaries it will behave like this and run super lean when they try to kick in.

Fuel in wrong spot and your primaries decreased drastically.

thewird

iTrader: (8)

It requires 3.5-4.5ms to idle at 18-19 inches of vacuum. I had the secondaries setup to come on at 2psi and the problem happens in vacuum. It's not one specific spot where it happens, its just a general lack of fuel that happens anytime you need fuel.

thewird

Sesshoumaru

iTrader: (1)

Have you watched the fuel pressure when this happens?

It might be 40 under low load but might drop with higher flow demand.



The following can effect the ms at idle-

Injectors seated properly

Atomizing screens

Vac line for the primary air bleeder

thewird

iTrader: (8)

I've been mentioning that to the owner of the car a few times and apparently the shop working on the car checked it twice and said it was OK but how much they tested it I don't know. He's been meaning to get an aftermarket FPR which would make checking fuel pressure a lot easier. If you look at the fuel map in the pictures, notice how much injector ontime is required in medium vacuum.

thewird

Bwek

iTrader: (4)

When the secondaries come online it would cause the Fuel pressure to fluctuate enough to lean out? Is that what it could be?

I'll see if I can find a remote mount fuel pressure gauge See whats happening when its being drivin

Sesshoumaru

iTrader: (1)

If it does this under light vacuum I would just run a standard guage under the hood and use the windshield wiper to hold it down.

That way you can see it while you drive but it's temp secured.

I don't think it's the secondaries because thewird said they were not coming on when this happens.

I personally log alot so I can see what the system is doing.

This is why alot of people buy fuel pressure sensors - so they can log it under load.

They are about 30 bucks and very easy to install with the spare A/D on the haltech - leaving the wb to the O2 input set to 0-5V.

I like it that way so that you can see the AFR on the guage page and frees up the spare AD

Bwek

iTrader: (4)

I just picked up the car and drove it to my place

I have Better understanding of what it is doing

It feels like the fuel pump is way to small, So under light load its okay, but at any rpm if you give it more load it slowly leans out as i give it more throttle or Rpm

Then there is the issue of 3000-3500 rpm

I didn't get a chance to log it tonight as it was too late

Tmw im going to swap my Fd fuel pump in there the 255 walbro doesn't sound all that great to me and try some logging

thewird

iTrader: (8)

^ I said the same thing. The pump makes a strange noise when you give it any throttle but again the shop tested everything and said it was fine >_>

thewird

Sesshoumaru

iTrader: (1)

Were you able to monitor the fuel pressure under load then?

Bwek

iTrader: (4)

So first thing this morning I changed the fuel pump it was bugging me

i didnt trust the fact that the shop said it was okay....

Turns out Thewird and I were right about the funny noises

ugh friggin fuel pump... now it floods even when running lol

So im looking for a large street port map with 550's and 1680's and a hybrid feed turbo if anyone could get me in the right direction it would be great

thewird

iTrader: (8)

I could adjust the fuel map to a car I tuned with the 550's if thats the case :P

thewird

Bwek

iTrader: (4)

okay sweet maybe You can email it to me and i'll load it up and bring it over to you tonight or tmw? Im up all night bro

thewird

iTrader: (8)

MSN me lol.

thewird

Sesshoumaru

iTrader: (1)

People often assume it's not a fuel pressure problem when they see correct pressure at idle but what they are forgeting about is flow.

thewird

iTrader: (8)

Well as long as the fuel pressure is stable and does what it needs to do, so will flow. But anyway, learned my lesson about checking things myself and not always taking mechanics words for it even if they say they checked it twice >_>

thewird