Zmanco Posted January 28, 2010 Share Posted January 28, 2010 Getting the inverted setting wrong should not damage the VB921. All the driver does is act like a switch opening and closing to control current through the coil. All the invert setting does is determine if the switch opens or closes on the trigger event. The stim is the easiest way to check if it's ok or damaged. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Yes, and I just hooked it up to the stim and its firing (yes!). Also, with the key switched in the "on" position, there is not 12v to the coil positive, this is an issue, correct? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 Trace it back - is there 12V at the relay board for the fuel pump and coil? If yes, then there's a problem with the wiring to the coil. If no, then start looking for issues with the relay board. Is the relay properly seated? Also, you might want to power the pump from only the relay board so you don't have that issue to deal with. You don't want to land up with a problem in the relay board masked by power from the stock fuel pump wiring being fed back into it. I doubt the stock wiring is robust enough to power the new pump, at least not indefinitely. A word of advice with electrical wiring: make it as clean as you can now. If/when you have to come back and trouble shoot it later, it will only be more confusing. Label everything with tape and permanent marker. Take notes on the MS diagrams and don't lose them. Wiring is only hard when its messy and undocumented. The extra time you spend now will be more than saved by a) not being stranded on the side of the road later, and actually being able to make changes and additions later without causing other problems. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 This is probably an EXTREMELY stupid question, but I am using a fluke and it will be DC, correct? Sorry lol Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Correct me if I'm wrong here, but when I turn my key, my fuel pump primes for about one whole second, then turns off. According to this diagram, if the fuel pump turns off..won't that cut the power to the coil too? Sure looks like it would... Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 Yes, all the voltages you will measure for MS are DC. It doesn't matter what brand multi-meter you use. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 Correct me if I'm wrong here, but when I turn my key, my fuel pump primes for about one whole second, then turns off. According to this diagram, if the fuel pump turns off..won't that cut the power to the coil too? Sure looks like it would... You are correct (I don't like the way this diagram suggests you wire the coil for this very reason). Here's a suggestion: connect the meter to the coil and ground and then turn the ignition and watch for the meter to read the voltage while the pump primes. Hopefully the meter will respond fast enough to get a quick read. Also, IIRC, you may be able to set the pump prime time with MS1/E. You might temporarily extend it to 2 or 3 seconds. An alternative is to just temporarily power the coil directly from the battery. But if you decide to try this, make sure you use a 10A fuse in case something goes wrong. If the car starts, then you know there's an issue with getting 12V to the coil. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Just tested it, the coil received a 12v charge when the pump primed! Right now...I'm just confused because plug will spark only when it wants to while cranking...am I not getting enough power while cranking or something?..... Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 JRight now...I'm just confused because plug will spark only when it wants to while cranking...What does that mean? ...am I not getting enough power while cranking or something?.....Battery voltage is around 11v while cranking which is good. Did you set the cranking RPM and flood clear values properly? The datalog you posted suggested they were still zero. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Yeah I changed them. I'm out of ideas as of now....this is extremely odd. I have power, the coil is getting power, the dizzy is giving a tach signal...what could it be??????? Quote Link to comment Share on other sites More sharing options...
letitsnow Posted January 29, 2010 Share Posted January 29, 2010 Does it only have power when the pump is priming? Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Yes, the coil has power when the pump is priming. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 letitsnow is thinking the same thing I am: leave the meter attached to the coil and see what the reading is while cranking. Remember, you have the fuel pump wired in parallel so you're also checking to make sure it's getting power. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 letitsnow is thinking the same thing I am: leave the meter attached to the coil and see what the reading is while cranking. Remember, you have the fuel pump wired in parallel so you're also checking to make sure it's getting power. So put the multimeter to the positive side of the coil and see what it says while cranking, correct? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 So put the multimeter to the positive side of the coil and see what it says while cranking, correct?Yes. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Okay, did that, and we have ~11.5v to the positive side while cranking. Now what?? Right now, my only thing I can think of is wait and see what that VB921 upgrade/replacement will do for me. Can you think of anything else I could try? Lets see here: 1. I have power to the coil positive (12.Xv) while the fuel pump primes when the key is turned to the ON position. 2. I have power to the coil positive while cranking (~11.5v) 3. When plugged into the stim, the spark light (D14 I believe) flashes, as it should. 4. My dizzy is sending an RPM signal to the computer. 5. Using a fresh spark plug, I am getting no spark. This is what I have come up with through my diagnosis process. If the VB921 wasn't working or slightly damaged, would the spark light on the ECU still flash without getting spark to the plugs?? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 29, 2010 Share Posted January 29, 2010 Are you sure you don't have spark at the plugs? A simple test is to pull the plug wire off at the coil and while someone else cranks the engine, bring it back close to the post. If you see the spark jumping then there's probably nothing wrong with ignition circuitry and it's instead a MS setting. CAREFUL: you can get a minor shock from this - it won't hurt you, but it's not pleasant. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Okay, so pull to wire from the distributor to the coil off on the coil side, and while someone cranks, slowly plug it back in and the spark should jump and i'll be able to see this? I guess I'm not sure which "post" you're referring to. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 29, 2010 Author Share Posted January 29, 2010 Here is my most recent MSQ file!! http://www.filedropper.com/1-29-10 Quote Link to comment Share on other sites More sharing options...
naviathan Posted January 29, 2010 Share Posted January 29, 2010 Did anyone else notice the 6ms Crank Dwell and 4ms Run Dwell settings? Isn't that way too high? Quote Link to comment Share on other sites More sharing options...
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