Well... sleep is taking over. The intake manifold is prepped and ready to test.

I got a power supply, BNC connectors for an analog input, AEM 100psi pressure sensor, and the ATi Box all ready. I need to figure out how I'm going to tap into the fuel line now ghey.

 

I took some more videos to help people understand what we're up against.

Video: 2 hours after key off.


Video: 3 sequential starts after the previous video

 

So the first video, is that the worst of it? Seems like a the type of thing that happens when FP is relieved from a system and it takes a few to get pressure again, which also results in a longer first start and quick starts thereafter.

When are you going to be able to get the pressure transducer logged for FP? Previously it was mentioned that a FP gauge was bouncing around during cranking. It's hard to take much from watching a gauge compared to a high sampling rate on a pressure transducer, but if a pump was cavitating, you would see the gauge bounce.

What do you think?

 

Tony,
I have the AEM 100psi sensor. I'm getting a three way 1/8" NPT fitting. I'll thread the sensor into the "t" and thread in two barbed hose fittings to run it in series.

I have a power supply that I can set to 5v's for a signal reference.

I also have two aligator clips that have a BNC connector on the other end. I plan to clip the signal and ground to the aligator clips and plug the BNC connector into the ATi Analog Input Box.

I then have to power and setup the ATI box, connect it to my work computer, definte the channel and logging frequency (up to 1Hz)

I was hoping to do that tonight, but I didn't get it all rounded up at work. I plan to have the whole thing setup with fittings ready to go and deutch connected before I leave work tomorrow.

I'm really not excited about cutting my factory fuel line.

I also need to power my wideband to an external power source that is uninterrupted by starting the vehicle and wire it directly into the ECU so I can take advantage of the new DMA logging speeds!

*****

It's really quite apparent that my car sucks when compared to FastFreddies hot starts. (Precision 780's)

 

Ernie,

What logging speed upgrade are you referring to?

 

R/T, nice timing on the videos. I just logged fuel pulse width contributions, fuel rail pressure, and a few other parameters during startup after letting my car sit for two hours. The temp needle and time to light up were about the same as what you showed in your video. What was perhaps a little different is that the car almost lit up on the first/second crank, and then fell flat for a bit before finally lighting up. This can be seen in the RPM trace in the plot.

What's not shown in the plot is that fuel rail pressure was still 14 psi after the car had been shut down for 2 hours. Surprised me a bit. As the plot shows, rail pressure immediately shot up to 47 psi as soon as cranking was initiated.

 

Tony,
I spoke with one of my co-workers who used to work at Banks (Diesel) on several of their race cars and he suggested that I put a check valve pre-fuel rail to sustain the fuel in the rail.

Burton said something to the effect of... the fuel bleeds off and the fuel vaporizes in the injectors. He told me he had the same project on one of his FI v8 projects and the solution was to put a check valve in.

I've got my eyes on this hummer... although burton said we could make a much better/cooler one with a softer spring.

http://www.anplumbing.com/shop/index...t=Check!_Valve

 

Mr Fred... do you have a picture of where your fuel pressure sensor is located? Maybe just an explanation would suffice, but I like pictars

Hammans,
DMA Live Map that was available on v5.10. I'm p(r)aying that it will be ported over to the v7 patch so we can log at 5-10 times faster than MUT logging.

 

Ultimate Racing makes an adapter that goes between the rail and the inlet fuel line:

http://www.ultimate-racing.com/Produ...eAdapter.shtml

I've got a Kavlico 75 psi sensor attached to it and wired into my ECU. :-)

 

Bah! You win. I have a lot of catching up to do.

 

lol. I had been planning the fuel rail pressure logging for over a year. Just got it working about two months ago. You'll catch up to me in a matter of days. The original intent was to look at whether fuel rail pressure was saturating as I pushed up the boost beyond 26 psi and also as a potential failsafe sensor for the infamous Whinebro pump. Turned out to come in handy for troubleshooting these injectors.

 

I have FIC 750's... Mikey is the one with the Precisions . And it is weird because I used to have hot start issues, but now I don't... Seems like you have a cool little "test bench" set up to test these injectors. Like I said, I will be up in B-ham on Friday so I will be able to drop by and see whats happening. I will try and give you a call tomorrow to see what your schedule is like.

 

There is an actuator in evoscan we can turn the pump on......I did this and my fuel pressure went from zero to 38 psi so everything was primed, etc.

The car started the exact same?

I will get some videos as well today, I will also get some videos of my FP gauge during cranking - I will just get my gf involved. I also have plans to put new plugs in after work in our warehouse friday - when I do that I am going to put ice packs over the injectors for 30 min and see if temps are playing any role at all on my end.

 

Grabbing battery voltage would be helpful as well.

Just for reference, what batteries are you guys using? Those orange dyna-batt knock off batteries drop voltage like crazy at high current draws.

One other item related to voltage. The ECU use a voltage reference to determine the battery voltage. Has anybody looked at the hardwire to see where this reference comes from? I assume it's just from the power input of the ECU. The injectors on the other hand have a seperate circuit where the current draw from the injectors will cause a voltage drop through the wiring. Thus your voltage reference really doesn't reflect the true voltage at the injectors (same condition for ingition dwell time).

I point this out because while the ECU may be showing you are getting 10V while cranking, the injector may be seeing signifigantly less. Actual voltage at the injector like suggested by Tony should definitely be looked at.

 

I can include battery voltage this afternoon.

Wouldn't you think it to be a little strange for Mitsu to set the injector latency value based on a voltage different than the voltage than the injectors actually see?