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Need help with my L28ET!


jacob80

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Hey guys,

 

Back at it again with this Megasquirt troubleshooting stuff after getting the car running pretty well and ready to start tuning it. Hope to drive this baby on a 800 mile round trip in two weeks, so I hope to get some help prior to then!

 

I was fortunate enough to take the car out for a little cruise and get some datalog time in, as well as getting some use out of VE Analyze Live. Unfortunately, I'm not 100% satisfied with how things turned out, but overall, the car is running and nothing catastrophic happened. There are a couple things I'd like to point out. I've included a datalog and my current MSQ in this thread for your analysis.

 

1. The car won't start up nicely. It acts as though it wants to start, and then dies immediately or just putters a couple of times. I am forced to pump the gas pedal slightly in order to get it to idle. Once it has started, it idles just fine thereafter. What adjustments can I make to improve my starting dilemma? I attempted to adjust the ASE curve, but that didn't do anything. I also increased my cranking advance to 20 degrees, but that didn't seem to do anything, either.

 

2. According to the datalog, I do not appear to have any resets (SecL counter doesn't restart). However, when accelerating, the car tends to blip in and out, if that makes sense. If I were to describe it, I'd say it feels like the spark and fuel shut down for a split second. This seems to happen especially when I was attempting to tune the car in the upper RPM ranges. Every time I would, it felt like I was hitting the rev limiter. In the upper RPM ranges I was able to record in the datalog (3500-4000 RPM), I would experience this. This could be just a lean condition, but I kept bumping up the VE cell values in the region with little to no improvement. I believe one of the cells eventually hit 120!

 

3. Why is my warm up enrichment constantly on? I noticed this on the main Gauge Cluster tab of Tuner Studio. The "WUE" indicator is constantly green, even though the greatest value for warm up is 160°?

 

4. A couple of things unrelated to tuning: once in a while, when I turn the key to the on position to prime the pump, nothing happens. I then click off to accessory and then click back to the on position, and it'll work. It's very sporatic. I've checked my switch signal to the relay board and it's solid and I replaced all relays without any success. I did notice the relay closest to the injector 12 V drivers does get warm, even when I replaced it. I'm not sure if this means anything, just thought I'd throw it out there. I also notice that when the car dips down in an idle or I almost kill it when engaging the clutch, the fuel pump relay clicks a number of times. Is this normal?

 

Those are my main concerns at this point. I'd like to start getting into some boost and tune the car in the upper kPa regions, but I'm deathly scared of detonation and this hesitation up top is really discouraging.

 

If you guys could help me out by looking over my datalog and MSQ I'd really appreciate it. I'd ideally like to drive the car on a 800 mile round trip in two weeks, but I need to get this figured out first.

 

Thank you guys for your help, it is much appreciated!!

 

Datalog:

 

https://www.dropbox.com/s/s8ofmikz78ul8 ... vebaby.msl

 

MSQ:

 

https://www.dropbox.com/s/tcaz08wj2rkt4 ... ntTune.msq

 

Configuration:

 

1973 Datsun 240z

L28ET (2.8 Liter OHC)

HY35 Turbocharger

RC Engineering 550cc Injectors

FMIC

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Your warmup enrichment wont turn off unless the taper% cell for 160 degrees is set to zero. After you do that, open your VE table and scale all of your cells by whatever percent your 160 degree warmup cell was set to.

 

The dropping out at high RPM could be a coil dwell issue. I had trouble with that. Make sure that max dwell is set to at least twice what your max spark duration setting is. This is assuming that you have a single coil. If not, then the dwell may be set with different

 

parameters but may still be the problem. Also make sure your plugs are gapped tightly. .025 works for me.

 

Your other problems just need to be tuned around, like the sputtering when starting. Look at what cells in the VE table your car goes to while cranking and afterstarting and experiment with them until it starts reliably. ASE and WUE should be tuned after you have done that.

 

I cant see your datalog, it says its a bad link.

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  • 5 months later...

And the WUE is where I"m struggling now. No matter what I do I can't get my car to run with the WUE ending value at 0 I had my car running pretty good, then realized I had a bad thermostat and it wasn't really getting over 140 degrees. Now that I have it warming up right i'm trying to taper off the WUE and It just does not like it AT ALL!!! 0 WUE = not running for me.

 

 

How are you making out with your setup now??

 

When you pump your pedal you are actually telling MS not to inject any fuel so i'd dare say you need to lower your WUE values to lean it out some.

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motomanmike-

WUE of 0 means inject no fuel, so you are getting the expected

results. The value is expressed in percent.AND MULTIPLIED

against the warmed up pulse width.

 

100% = 1.00, and means no enrichment. (PW * 1.00 = PW)

0% = 0.00 and means not fuel at all. (PW * 0.00 = 0)

 

The terminology is occassional confusing, with a normal reaction

to set values to '0' when we want to represent nothing, but that

is not what is needed for ASE or WUE.

 

Jacob80-

You may be going the wrong direction with the VE cells. If you

are over fueling in a particular load it will register as lean on the

wideband, and the resulting stubble will feel similar to the seat of

your pants. My VE table at 180KPA is about 105 for the 3500 to 4000

RPM range. I am not dyno tuned, so I don't recommend my values,

but if adding more fuel in that range does not help, you should

consider leaning it out there.

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So your ending value on the WUE taper at say 160degrees should be 100% (using tunerstudio)? Not trying to hijack jacobs thread either but it might help him understand too. If that is the case will the WUE green icon go away once its past that temperature? Mine never goes off even at operating temperature. But i've had values lower than 100 in the last bucket, like 32 currently. After reading this yes, the base maps in tunerstudio examples all end with a value of 100. Hmm

 

 

Jacob, I had a thought too. Have you tried pulling the injector bank fuses from the relay board and lowering the rpm in tunerstudio lower than cranking to see if you get a reset? How about unhooking the coil in the same fashion and see if you experience a reset. Might give you some insight on whether its the injector or spark part of the system thats causing you issues. Do you have a stim?

Edited by motomanmike
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Your ending value should be 100%. If you have it set to 100% at 160 degrees and

the WUE indecator does not turn off, I would first suspect the CLT is not calibrated

for your sensor and check to see what TS reported for a temp and compare it to

either the dash guage (if you trust it). It does not need to be 100% in agreement,but

should be close.

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