First start issues

Tuning concepts, methods, tips etc.

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Laminar
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Re: First start issues

Post by Laminar »

Awesome! :D

Maybe start a new thread a post the msq and tooth log with the VR sensor and see if any fresh faces have input on what the tooth log should look like for the VR sensor.
alex240
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Re: First start issues

Post by alex240 »

Actually it works now for some reason. Switched it over to fully sequential and the cam signal is fine. I have no idea what happened but I'm gonna guess the polarity was set wrong in tunerstudio the first time. Now I just have to figure out how to get it to idle without throttle.

A big thanks for all the help guys! I really appreciate it!
Laminar
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Re: First start issues

Post by Laminar »

For the stock Explorer IAC, I used a diode as described in the manual:

Image

At the IAC, the white/light blue wire gets wired to the MS3X idle input (pin 9), the red wire is +12V input.

Here's my idle setup:
Image

If you leave "Run valve before start" on the engine will fire sooner, but you'll hear the IAC whistling with the key on/engine off.

And here's the Warmup Idle Duty settings as I'm still running open loop:
Image

It ends up idling between 850-900rpm once warmed up with my setup. You can adjust the idle duty to get the idle level you want while warmed up. Usually the top temperature is 160 degrees but I found the rpm changed between 160 and 170 degrees at the same idle duty, so I upped the top temp and adjusted the curve for a nice warmup.

Because the IAC gets pulled toward the engine by vacuum while running, you can't really test the IAC while it's off the engine.

With the engine running, you can go into "CAN-bus/Testmodes" and test the idle valve by sending it direct outputs and correlating that to RPM.
alex240
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Re: First start issues

Post by alex240 »

Thanks Laminar!

On another note I think I found a new problem- I pulled the header off the driver side and noticed that the exhaust ports for cylinders 1 and 3 were wet with fuel and the exhaust ports for cylinders 2 and 4 were bone dry and covered in carbon. What could that mean?
Laminar
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Re: First start issues

Post by Laminar »

Plugged injectors maybe? I know when I first ran my engine on the stock 19lbers I wasn't hitting on all 8, I threw my new 36lbers in my ultrasonic cleaner for a few cycles and I ran some injector cleaner through a couple tanks of fuel.
alex240
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Re: First start issues

Post by alex240 »

Alright new question which needs to be resolved before I start the car again- Laminar how is your alternator wired? I have a 4g and it gets hot to the touch with the key on but engine not running. I already burnt up one alternator grrr
Laminar
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Re: First start issues

Post by Laminar »

I have the stock Explorer alt wiring. The thick gauge wiring goes from the alt terminal to the battery + distribution block in the engine bay (the battery is in the trunk).

Image

The light green/red wire is the ground switch charge malfunction light. The yellow/white wire is fused and goes to +12V during key on/start/run.

I started with a junkyard alternator and it died after a couple weeks. I got a remanufactured Duralast alternator from AutoZone and that died in 1 day. I got a brand new Duralast Gold alternator from AutoZone and that has been fine for a few hundred miles.
alex240
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Re: First start issues

Post by alex240 »

Hmm looks very similar to how mine is wired up. The 2 gauge yellow wire runs right to the B+ post on the alternator from the positive terminal on the battery. The smaller yellow wire runs right to the b+ terminal. The green/red wire has a 470 resistor inline and runs to the interior fuse block which is 20A fused switched 12v. The engine ground is attached to the alternator housing in the bottom of the picture. From testing it only gets hot if the yellow wire is connected to the B+ terminal, when it is disconnected the problem goes away. Do you see anything wrong with this layout:

Image
Laminar
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Re: First start issues

Post by Laminar »

The yellow/white wire is the 12V signal wire, if it's disconnected, the alternator won't produce a charge. How hot is hot?
alex240
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Re: First start issues

Post by alex240 »

Gotcha. But when it is connected I burn up alternators. Hmm Ill keep thinking and researching.
Laminar
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Re: First start issues

Post by Laminar »

http://www.pirate4x4.com/tech/billavista/Wiring/Part2

The author addresses your setup directly. The yellow/white sense wire should reflect actual voltage at the fuse box so that the alternator will increase or decrease its charge level in response to varying electrical load. With your setup it will only ever sense its own direct output so it can't react to what the electrical system is doing.

He also advises against wiring the alternator output directly to the B+ terminal, instead it should go to a main distribution point from which the fuse box and other electrical accessories get their +12V line. This way the battery only sees the total voltage in the system after being pulled down by all electrical components. If the alternator goes directly to B+, the author claims the battery will be subject to much higher variations in voltage which isn't good for it.
alex240
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Re: First start issues

Post by alex240 »

That was a very helpful link, thank you. I have moved the 2ga alt output cable and the yellow/white voltage sensing wire to the power distribution junction by the fusebox. I still have the exciter wire connected to the interior fuse panel (12v switched). With the key on but engine not running (12v applied to the exciter wire) the rectifier/voltage regulator on the back of the alternator gets too hot to touch in about a minute (Also it does not charge when the engine is running). From the diagram you posted it seems that it should only receive power while cranking or running the engine, but NOT with key/accessory power on, correct?
Laminar
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Re: First start issues

Post by Laminar »

Right - the battery light should be off in the accessory position and on in the run position with the engine stopped.

I turned my key to the on position and watched the temp of the aluminum heat sink with an infrared gun. After 2 minutes it went from ambient of 84 degrees (F) up to 87. After five minutes it was 91 degrees.
alex240
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Re: First start issues

Post by alex240 »

Good to know. I had my battery and the new alternator tested at autozone today...battery is fine but I burned up another new alternator. I got a warranty replacement but I'm not too keen on slapping it on there just to burn it up again...

So here are some more details on the wiring in my car- This is a track car so I do not have a traditional ignition switch with "acc", "run", "start" positions. I just have a switch panel with a single "power" switch (I guess that would be the same as the "run" position since it turns everything on) and a momentary switch for the starter. I also don't have an alternator charge lamp.

So, questions in light of this setup-

1.) Do I NEED a charge lamp?
I would think this is unnecessary since the voltmeter in megasquirt should tell me everything I need to know about the charging system.

2.) If I don't have a charging lamp do I need to increase the resistance of the 470ohm resistor or add an additional resistor in parallel to simulate the presence of the lamp?

3.) Is the sensing wire (yellow/white) really supposed to be hot at all times as it seems to be in the diagram above?

4.)The only other discrepancy I can see is that I also don't have a 15A fuse on the sensing wire, I wouldn't think that would cause my issue of burning up rectifiers but I'm not sure of anything at this point.

I suppose the other possibility is that the last alternator I got from the store was defective to begin with. If we can't identify any other problems in the wiring I will hook up the new one and see what happens.
Laminar
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Re: First start issues

Post by Laminar »

1/2. If it were me, I'd wire everything up like it's "supposed" to be, and see if the alternator lasts longer. If the charge lamp is in place like it's supposed to be and you're still killing alternators, you know to look elsewhere, instead of killing 5 more alternators playing with resistor size or wattage.

3. I do believe that one side of the charging light should be hot at all times. That way if the alternator is producing less than 12V (when the car is shut off or the alt has failed), the lamp will see a voltage difference between the battery and the alternator and light up. Alternatively, if the voltage regulator has failed and the alt is producing 16+ volts, the lamp will see a voltage difference of ~4+ in the other direction and light up. This setup lights the lamp if the unit is under or over producing.

4. I'd go back to the first answer - make everything "as drawn" and see if that does the trick.

Where are you getting your alternators? Like I mentioned before, I've killed two - first was a $25 junkyard pull that lasted a couple weeks, and the second was a remanufactured Duralast from AutoZone that I killed in one day. Since then I have about 300 miles on a brand new Duralast Gold with zero changes to my charging system since day 1.
alex240
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Re: First start issues

Post by alex240 »

I have been getting the duralast remanufactured alternators from autozone. Sounds like they may not be very reliable.

I will replicate the stock setup to a T and see what happens.
Laminar
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Re: First start issues

Post by Laminar »

I think it's about $40 to step up to the brand new Duralast Gold, I'd try that and see if it helps. Well worth it if it saves you yet another trip to the store and exchange. Plus at some point I feel like Autozone would cut you off. :D
fxnick
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Re: First start issues

Post by fxnick »

Laminar wrote: Tue Jul 21, 2015 4:16 pm For the stock Explorer IAC, I used a diode as described in the manual:

Image

At the IAC, the white/light blue wire gets wired to the MS3X idle input (pin 9), the red wire is +12V input.

Here's my idle setup:
Image

If you leave "Run valve before start" on the engine will fire sooner, but you'll hear the IAC whistling with the key on/engine off.

And here's the Warmup Idle Duty settings as I'm still running open loop:
Image

It ends up idling between 850-900rpm once warmed up with my setup. You can adjust the idle duty to get the idle level you want while warmed up. Usually the top temperature is 160 degrees but I found the rpm changed between 160 and 170 degrees at the same idle duty, so I upped the top temp and adjusted the curve for a nice warmup.

Because the IAC gets pulled toward the engine by vacuum while running, you can't really test the IAC while it's off the engine.

With the engine running, you can go into "CAN-bus/Testmodes" and test the idle valve by sending it direct outputs and correlating that to RPM.
Hi,
Im having trouble with getting my explorer engine to idle. I have pretty much the same setup as you, LS coils too. I actually used your tune you posted on here as my starting point. Thanks!
Changing the iac freq. and duty seem to have no effect for me.
Have the iac wired to the ms3x idle pin but without the diode, I was curious if you found you needed the diode to make it work?
I have read on here that this diode is built into the ms3x board.
Explorer 302/LS Coils/Full Sequential/48LB Injectors
Laminar
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Re: First start issues

Post by Laminar »

The portion of the manual I quoted mentions adding the diode to an MS3X setup, so I assume it's not built in. I'm not sure if it worked without the diode, that was quite a few years ago.

You can get diodes here.

To test the IAC, turn down your throttle stop until RPMs are maybe 900 or so, then go to the Output Test Mode - Idle Valve and close off the valve until you see some effect on RPM. I found the valve was effective from about 25% open to 50% open. Outside of that range, there didn't seem to be much effect.

I've done a lot of work to my tune since then, and I've incorporated the new idle VE and idle timing features introduced since I first started.

Open that tune separately and check out the engine states setup, and then look through the closed loop idle settings. Note I've also changed heads and cam since then, so the MAP values won't match what you see on a factory Explorer setup.
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