newkie

So, after taking the car for a spin today i noticed the bigger gap on the plugs seem to have made the car alot better to drive. It still stumbles but alot less, and further down.

I guess the theory about to large injectors may hold some water after all. I will probably be getting smaller ones. I am looking at up to 400 HP (crank) what size injectors would be optimal for e85?

TurboTommy

Also, most wideband O2 systems don't know that you're running e85; they just use the same scale as if you're running gasoline. So, you are supposed to see 14 to 15 air/fuel at part throttle.
Also, there's no way your car will run right with that spark plug configuration
(BPR8ES is way too cold especially for e85 and 0.5 mm is a ridiculus small gap)

newkie

Well the wideband system is obviously set to E85..

And i changed the plugs as you can see a few posts back. BRP7ES 0,8 mm gap.

Duke

It's easier to just leave the wideband set to regular fuel and shoot for the same afr values as when running on regular gasoline.

newkie

Since im not used to AFR at all, any setting will do fine for me :-)

newkie

So. Im bumping this thread again. Changed to smaller injectors (83 lbs/h) these will definitely not be to big.

The car runs great for about thirty seconds and with great im talking dream like. After that it just dies. Stumbles a couple of times firtst. I can keep it alive wit the throttle.

I also remember a detail from last year. The car ran alot better back then but still had this problem. Even though the car ran fine i could not for the life of me get boost over ,7 bar. The WG-spring should hold back atleast 1 bar. Same problem seems to be pressent this year.

Any more thoughts?

DLS

I answered in the swedish 944 forum instead

newkie

Making a bump again...

Motor still runs like crap. Made a little clip, please listen to it and the puffing noise. What is going on?

I pinned the throttle down at the time so it's in the exakt same possition the entire clip. should be around 2000 RPM...


Thoughts?

These are the changes made to the car...

Head
-----------------------------
48 mm stainless steel intake valves (Ferrea)
Reworked intakeports (Ultra motors)
Titanium retainers (Milledge)
Better valvesprings (Milledge)
Camshaft (Milledge) <--- On a shefl, original cam for now
9:1 CR

Block
-----------------------------
Headbolts (raceware)
Rebuilt during winter 2009/20010 All new bearings and gaskets
original Head gasket

Elektronics
-----------------------------
Mass air flow system (H5M5) MAF (Tomas @ 944 sverige) Has worked fine before
Chip for etanol and 98 oktan (Tomas @ 944 sverige)
83 lb/h injectors (Delphi)
044 fuelpump (Bosch)
Profec B spec II (Greddy)
Wideband lc-1 DB (Inovate technologies)
Ignitionwires Mangecore (Lindsey racing)
New injectorharness and knocksensor harness (Lindsey racing)

New Idlevalve (Bosch)
New Flywheelsensor (Bosch)
New Engine temperature sensor (Bosch)
New oil preussure sensor (Bosch)
New tempsensor on the cooler (Bosch)
Switched out the DME

Air and exhaust
-----------------------------
Turbo is a fully upgraded T3/t04E with 360 bearings and GT shaft 60 trim, 0.63 a/r (Garrett)
Tial 38 wastegate
Audi TT blowof valve

Drivetrain
-----------------------------
Porsche GT2 pressure plate (Sachs)
968 cluthdisk (Porsche)
Lighter 944 flywheel (Porsche)

Chris White

Looks like an ignition miss to me – when the rpm falters a bit the O2 readings go lean. Most folks forget that when there is an ignition miss the gas doesn’t not get burnt – and the O2 also does not get consumed either. So even though you are sending unburnt fuel down the exhaust the O2 sensor will see the unused O2 and report it as a lean condition.

The Magnecore wires are famous for having crappy connectors at the plug end – swap back to some old stock wires for a quick test and see what happens.

Chris White

BTW – I am interested in your clutch system – you have a solid centered clutch without a dual mass flywheel – are you getting much driveline noise?

newkie

Hi Chris thanks for the reply.

It got me thinking. I had som arcing from my last ignition wires, hence the new ones. Not sure how long the bad ones where acctualy bad but they realy arced.

And i have noticed my injectors behaving strange while the imobilizer is engaged. They tend to open and close in what i can only describe as an unorderly fashion.

clickclick...click...clickclick... and so on. Today i listened more closely to it and think i hear arcing coming from inside the ignitioncoil. So i got to reading and...

This problem has been with my car since i bought it. I just though, thats what the immobilizer does to keep the car from starting. Because i did not investigate. I never noticed the coil.


A little hard to tell. But the injectors go "click" and the arcing sounds more like popcorn.

newkie

I haven't noticed any noice. Well there are some noice while engine breaking(?). Not sure how to translate that

But im not sure thats the clutch. Its hard to hear from inside the car though...

I must say i like the setup. It's supposed to have handle in more then 500 hp and it's smooth as freshly waxed... ehrm... car...

Sadly i haven't been able to do any real testing. But according to Duke it's been dynoed with over 500 hp without any issues...

Black51

Wow, that doesn't sound good... What is that buzzing in the cab? Which injectors are clicking? Are they the ones on the dead cylinders? Get new ignition wires too. If this is what is going on while the car is running, then that's the problem, or at least, part of it. Hopefully someone can lend you some known working ignition wires to see if the wires themselves are faulty. That way, it it's not the wires, you didn't throw a couple hundred euros down the drain. The problem may be somewhere down the line, but I would say the odds are the wires are the culprit for the arcing, since they're arcing.

As far as the injectors go, I can only guess that the harness is on its last legs. There seems to be some shorting or an outside interference going on. On that note, check all your grounds as well!

GL

newkie

The buzzing in the cab seem to be a sound the after market alarmsystem is making to tell me that the imobilizer is active. No cylinder seem dead, they just make popcorn instead of sweet power once in while

The ignition wires are fine. Almost brand new in fact. The arcing seem to be going on either inside the Coil and/or distributor... I'm not really sure wich injectors are clicking. I have a brand spanking new harness for the injectors and the knocksensor though.

Anyone know if the coil is shared by any other cars?

Black51

If you're sure the wires are good, then check the next things down the line. The coil, then cap and rotor(or vice versa). One thing at a time, and you'll find the problem.