µSquirt ( microSquirt ) powered Vanagon ramblings

[luftvagon]

We got a runner! I repositioned the hall sensor, and voila -- same software settings.. and it runs, and gosh does it run good. Best ignition ever.

The van is now running WASTED SPARK. Firing CYL1, and CYL3 at the same time followed by CYL2 and CYL4 at the same time. Fuel is still batch (ALL INJECTORS SPRAY AT ONCE). However, I could now run SEMI SEQUENTIAL -- if I wanted to.

Current conservative ignition map:


LOAD VERSUS RPM AND IGNITION ADVANCE

[luftvagon]

Here is my new ignition map...



I get a little ping on no-load de-accel that will need to be corrected.

[luftvagon]

Slight adjustments, to see if it fixes the ping on de/accel.



AFR to match:

[luftvagon]

UPDATE:

The $30 fuel pump failed today. We were on our way out of town, luckily 2 miles away from the house, when van suddenly started losing power. With pregnant wife in tow, we decided to head home, and investigate. When we got home, I popped the engine compartment lid, and went to town diagnosing the issue. The ignition ground wire was lose and I thought to my self, ez-fix. Out of blue, I also decided to replace my original fuel lines on top of the engine, with FI hose. A twenty minute job. Couple of key cycles to prime the fuel lines, and the engine came back to life running strong with no loss of power. Not even two minutes into idle, and the engine cut off.. Strange. Hop back into the cab, quick key cycle, and I was no longer hearing fuel pump cycle (a non stock fuel injection feature).

Maybe I blew a fuse? Maybe the fuse vibrated loose. I did have fuel pump fuse out in order to drain fuel out of the system by cycling the key, and starting the engine without fuel pump running..... No go! Fuel fuse still intact. Quick volt meter, and power and relay are working, and power is being feed to the fuel pump. Yikes! Take the belly pan off, and check the fuel pump. Power available at fuel pump, but fuel pump is dead -- at 2000 miles...

Maybe a fluke? Maybe because I had it sandwiched between two filters...



Regardless, it's dead. I am calling the mfg tomorrow to see if I can warranty this item, if not, I am going to be buying a slightly better fuel pump for $48. I still refuse to run the $150 Bosch or the $99 replica.

If you have bought the $30 fuel pump based on my recommendation, please check if your pump is overheating, and if it is, maybe it should not be used with the pre-filter. I will update the documentation accordingly.

[rustbus]

Tonight I am going to experiment building a fast-idle valve using a $15 canister purge solenoid from any older or newer GM vehicles. The part and the pig tail could easily be found at the junk yard on any GM vehicle. Originally I wanted to use GSXR Secondary AIR valve ($7 shipped), but I feared I was not going to be able to find the connector.

The goal of this project is to raise my idle by at least 200-300RPM. I'm shooting for 900RPM hot, and 1200RPM cold (< 100F). My warm-up enrichment ends at 90F.



Oreilly part #: CP561

It also uses the standard GM two-prong connector. More updates tonight with pictures, and hopefully video of solenoid in action.

This could easily be integrated to replace AAR, for you stock guys.

Hi Luftwagen,

great thread!

Im considering a visit to the junkyard today to grab a couple of these air valves like you've used to replace the AAR. i have a Camper special and the cold idle is always a challenge. i've been through a couple AAR's and each one i've adjusted wide open and while the each behave a little better than the last, its inconsistent and still at best an 1100rpm idle. i'd like to hit 1200+, and i would love to have it on a manual switch so i can switch it off when the heads hit 200*.

so enough about me, its been nearly a year since you've installed this GM part - any issues or things you would change or do differently with respect to its install?



on a separate note, my ~150$ bosch fuel pump makes strange noises at 10,000km so im not all that impressed.... I should note i had a plastic fuel filter upstream and a Canton racing products high pressure filter on the discharge side.....pressure was good - until my pressure gauge froze up

[Amskeptic]

I like the thought of looking for more cold idle air (you can also jack up idle timing with a bit of futzing).

The 10mm inlet between filter outlet and pump says "Do Not Make Pump Rollers Have To Suck".

[luftvagon]

Hello,
The solenoid could be attached to manifold pressure reference and Td of to the vacuum advance on the distributor. You could toggle it with a switch for more advance.

[rustbus]

Nice to hear from you Colin, i sure did enjoy our visit back in Salt Lake!

I didnt go to the junkyard today. its winter. ruins everything.

But i do think i'l use the o'reilly part number and see if the local part shops can find me a new one - I'll pay $15 over using 2 hours to go to the pickNpull, freeze my fingers, then chance it doesnt work.

Luftvagen, do you recall the approx. inlet/outlet sizes on this air valve? appears* smaller than the VW AAR.... which makes me question why it would be more effective (even though I can look through an AAR and see the entire diameter is not being used)

on the pump side, I am using the 'big exit' (11mm?) filter type..only other variable is that the BN4 heater supply is tee'd into the line between this plastic filter and the pump....but sorta thats how VW did it so must be OK..?..no check valve though, suppose the diaphragm metering pump might check it? wishful thinkning

sorry luftvagen! i'll get outta your thread!

[luftvagon]

You are fine. It's a little bigger than 5/16, if not bigger.
I had to make a coupler - a hose in a hose. It works and it does not leak.


I had a video of it raising the idle. It gives you about +300 RPM if used on the AAR plenum side.
You could plumb it from AAR intake plenum side onto Vacuum advance for extra idle advance i suppose.
You could also wire it into the thermo-time switch... endless possibilities.. i suppose.

[Amskeptic]

You could also wire it into the thermo-time switch... endless possibilities.. i suppose.

Settle down Vanagonstein.

The thermo-time switch is activated during #50 (start) only and is timed to break ground within 1/2 to 11 seconds max.
Colin

[luftvagon]

..so I am eyeballing a new addition to the van... CANBus. My ECU speaks CANBus.... This way I can aggregate CHT, OIL TS, OIL TS @PAN, OIL Pressure, Fuel Flow inlet, Fuel Flow outlet, Fuel Pressure, Ambient Temperature... display on dashboard, and log diag data along with engine telemetry (RPM,MAP,CHT,IAT,TPS)

[luftvagon]

I received my $28 fuel pump replacement in 2 days; the old one is going back for exchange.

[luftvagon]

This morning I took the van for another morning run/tune to do some additional tweaking, and to see why I'm getting ~16mpg.
To my surprise it was cruising at 13:1 AFR anywhere between 55-75 mph.

Now, AFR is useless without 3 dimensional context and condition:
RPM vs. MAP (load) vs. Ignition Timing

Going 65mph at 3400 RPM, with 70 kpa MAP, and ~40 degree advance, yielding 13 AFR could be considered a tad rich.
Why? Very low load in a steady state cruise -- there should be no reason why it could not go to 15.5 AFR.

To change the AFR for the condition, you could adjust fuel or ignition for the given RPM/LOAD. Either adjustment will also reflect the load. It will either increase or decrease the load, which means your target may have shifted in the same driving condition..... It's what the guys like to call "(spreadsheet cell) block" tuning. You will never get it right, because you will always be going back and forth.

I decided to leave the timing the same, and decrease fuel across the board for the following conditions:

• RPM higher than 2600 but lower than 4000
• MAP (load) higer than 50 but lower than 80

This resulted in a very interesting condition at 60-75mph. My engine load has decreased (MAP) and AFR went to 15.5 AFR to 17 AFR, which also meant the timing advanced further per RPM/LOAD map.... At one point time, somewhere close to 75mph, i was under 3900RPM, with engine load of 50-55, ignition timing at 45 BTDC (INSANE!!!!!) and 17 AFR.

I was starting to get a little worried, but interestingly enough my recorded temperature (GM COOLANT TEMP SENSOR ATTACHED TO TS II) started to DROP... the engine was getting cooler, requiring less load, and less fuel to maintain speed.......

Needless to say, my heart was pounding pretty fast, anxiously awaiting the last gasp of the little motor that could do more with less...

Who would've thought?

[Amskeptic]

I decided to leave the timing the same, and decrease fuel across the board for the following conditions:

• RPM higher than 2600 but lower than 4000
• MAP (load) higer than 50 but lower than 80

This resulted in a very interesting condition at 60-75mph. My engine load has decreased (MAP) and AFR went to 15.5 AFR to 17 AFR, which also meant the timing advanced further per RPM/LOAD map.... At one point time, somewhere close to 75mph, i was under 3900RPM, with engine load of 50-55, ignition timing at 45 BTDC (INSANE!!!!!) and 17 AFR.

interestingly enough my recorded temperature started to DROP... the engine was getting cooler, requiring less load, and less fuel to maintain speed.......
Who would've thought?

You decreased fuel ratio, why did the timing advance further?
Colin

[Xelmon]

I'm wondering the same.