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Old 08-14-2013, 12:19 AM   #1
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Default DIYPNP- engine starts then dies within seconds

Calling all Megasquirt Gurus for some wisdom... I'm trying to get my brain built DIYPNP to start and idle my car. However on the first try in a while it starts for a couple seconds then dies. If I try to start it again right after won't catch at all and just turns over.

It's a 1.6 with stock injectors, IAT installed, using a narrow band (just to get it to idle before my wideband install). I currently have the 10A fuse pulled like its mentioned in the writeups. The TPS in disconnected (do I need to change any TPS calibration settings?). I checked the timing and got it set to 10BTDC using the trigger wizard so I'm getting spark...

Any ideas on diagnosis?

Other info: I just pulled up the AFR and Spark tables and it goes well into the boost region so he loaded a boosted map, however I'm just try to get my stock engine tuned at the moment. Will this affect getting the car to idle?



Thanks in Advance for any input!
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Old 08-14-2013, 12:47 AM   #2
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Progress!!! I got the car to start up and actually idle for a while. I needed to jump the FP to GRND so I think something is wrong with my fuel pump relay circuit. Also the car idled pretty poorly. I tried adjusting the FUEL_REQ to get the narrow band to read 14.7 but it eventually stalled out.




PS: What graph variable are most useful to diagnosis when looking in megalog?
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Old 08-14-2013, 11:37 AM   #3
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It would help if you posted the actual log file and a copy of your MSQ. Exactly what variables are most useful depend on what the problem is, so please post the actual file; this will let anyone looking to help you comb through all of them.
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Old 08-14-2013, 12:29 PM   #4
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slow dying after start is often not enough afterstart enrichment or not for long enough. your wideband (or narrowband) o2 sensor will tell you.
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Old 08-14-2013, 02:10 PM   #5
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Originally Posted by Matt Cramer View Post
It would help if you posted the actual log file and a copy of your MSQ. Exactly what variables are most useful depend on what the problem is, so please post the actual file; this will let anyone looking to help you comb through all of them.
Okay, I'll get those posted when I get back home. Thanks.

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slow dying after start is often not enough afterstart enrichment or not for long enough. your wideband (or narrowband) o2 sensor will tell you.
That's what I was reading. I was playing with the warmup enrichment but I was needing to add a of of enrichment to keep it idling. Like 150% at 140 coolant temp compared to the basemap setting of 120%. And even then my narrow band was reading lean. Which make me think my REQ_FUEL is off but I used 1600 cc and 230 cc/min in the calculator.

I'm planning on getting my LC-1 calibrated and installed today to get better AFR to tune the warm up enrichment and see if that does the trick.
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Old 08-14-2013, 02:25 PM   #6
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here I have them. I still need to review them. I'm still trying to catch up on sleep after a long weekend with Hustler and I keep passing out once I'm home from work.

I did have a chance to review the map I loaded for you and didn't notice anything that shouldn't have you idling right now... but it sounds liek we need a little work on initial fueling.
Attached Files
File Type: msl Chris fuel pump jumped.msl (142.3 KB, 64 views)
File Type: msl Chris Fuel pump NOT jumped.msl (96.7 KB, 49 views)
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Old 08-14-2013, 02:33 PM   #7
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here I have them. I still need to review them. I'm still trying to catch up on sleep after a long weekend with Hustler and I keep passing out once I'm home from work.

I did have a chance to review the map I loaded for you and didn't notice anything that shouldn't have you idling right now... but it sounds liek we need a little work on initial fueling.
Brain, could you please email the original basemap to me? Just to reload it and start over since I fiddled with some settings so I'd like to start fresh again.

Also, I am still unsure about the fuel pump circuit. Does the DIYPNP you built require any modifications with my car other than pulling that 10A fuse?

Finally, for my LC1 install, does the input go into the db15 harness or replace the stock O2 sensor input?

Thanks for your help.
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Old 08-14-2013, 02:38 PM   #8
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While the AFM is in place, no, nothing.

you can keep the fuse in place either way.

I wired your diypnp so that the fuel pump ground goes out 2O. This goes back to the AFM connector (it's typically a 5v reference for the sensor). The AFM should continue to activate the fuel pump when the flapper opens like normal, when removed, you'll need to bridge the pin that goes out 2O with the pin that leads to the fuel pump realy.

wbo2: you can plumb it either way. I'm pretty sure I wired it up so you can run the wbo2 back through the stock wire, or directly to pin 4 of the db15. if you use the db15, make sure you unplug the stock o2 sensor.
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Old 08-14-2013, 04:50 PM   #9
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Quote:
Originally Posted by Braineack View Post
While the AFM is in place, no, nothing.

you can keep the fuse in place either way.

I wired your diypnp so that the fuel pump ground goes out 2O. This goes back to the AFM connector (it's typically a 5v reference for the sensor). The AFM should continue to activate the fuel pump when the flapper opens like normal, when removed, you'll need to bridge the pin that goes out 2O with the pin that leads to the fuel pump realy.

wbo2: you can plumb it either way. I'm pretty sure I wired it up so you can run the wbo2 back through the stock wire, or directly to pin 4 of the db15. if you use the db15, make sure you unplug the stock o2 sensor.
Sorry for requiring the spoon feeding... Where is the 2O and pin for fuel pump relay. Are these internal to the DIYPNP requiring me to just solder in a jumper?


edit:

Quote:
"This the the fuel pump relay connector located under the steering column (called Circuit Opening Relay in wiring diagrams). On the 1.6l cars its has 5 wires (like mine did) and on the 1.8l cars it has 4 wires and a different relay. I will only discuss the 5 wire relay. The violet trigger wire which comes from the ST Sign fuse (main fuse box in the engine bay) is what trips the relay and sends power to the fuel pump when the violet is 12v. The light green (already removed from the connector in the picture) is not needed as it is an extra fail safe circuit that was connected to the AFM to allow fuel only when the engine was running. Mazda got rid of this for the 1.8l. All I did was hook up the dark green/white fuel pump trigger wire from the LS1 PCM to the purple wire on the connector. Everything else (besides removing the light green wire) remains the same.



I connect the 2O pin in the DIYPNP to the Violet trigger wire and plug back in the ST Signal fuse?
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Old 08-14-2013, 11:40 PM   #10
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FML, my LC-1 isn't working correctly. It keeps blinking 7.4. I'm pretty sure it's wired correctly and the sensor is heating up. Research says often the controller or sensor is bad. I guess that's what i get for trying used parts but it was free from a friend. Looks like I'll be buying a MTX-L instead
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Old 08-15-2013, 08:36 AM   #11
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Quote:
Originally Posted by cyotani View Post
Sorry for requiring the spoon feeding... Where is the 2O and pin for fuel pump relay. Are these internal to the DIYPNP requiring me to just solder in a jumper?
no, you'll jump two pins in the AFM connector itself. This sends the fuel pump ground from the MS, to the AFM connector and back to the fuel pump relay via the lt. green wire.
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Old 08-15-2013, 11:33 AM   #12
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no, you'll jump two pins in the AFM connector itself. This sends the fuel pump ground from the MS, to the AFM connector and back to the fuel pump relay via the lt. green wire.
Okay, got it. Thanks for the picture. So this should solve my Fuel Pump issue.

My wideband should hopeful come in today so I'll get that installed and post up a msq and datalog file once I get the car to idle.
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Old 08-15-2013, 10:12 PM   #13
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I jumped the MAF per the picture you sent me and now the fuel pump primes properly. I installed my AEM wideband into the OEM wire location and changed the tunerstudio to single wideband and AEM and tried to start the car. It still fires up and stall within a few second. I tried changed the After start enrichment at the current temp from its default setting of 29% to as low as 20% and as high as 60% and it still stalls.

The car run a little longer with the after startup enrichment higher but still slowly starts running leaner and leaner until it stall

Attached are the datalog and .msq file.

Any thoughts on what settings I have wrong?



EDIT:

When I set the REQ_FUEL to 16.4 I can get it to idle around 14.7. However any slight throttle movement causes it to jump straight into lean and sometimes stall




.
Attached Files
File Type: msl Chris 8-15.msl (121.6 KB, 52 views)
File Type: msq cyotani1.msq (88.7 KB, 40 views)

Last edited by cyotani; 08-15-2013 at 10:35 PM.
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Old 08-19-2013, 07:16 PM   #14
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UPDATE: (so if anyone searches and finds this thread it might be useful... but probably not)

The car now runs!

The maf was jumped per brain's instructions and the REQ_FUEL adjusted until i got it to idle (it was changed from 12.9 to 16.5 i believe for it to not stall out). After I confirmed timing with a light and let the car warm up.

After I adjusted VE at idle section to pull largest vacuum. Then did some very conservative around the block data logs and VE analyze tuning. The magnitude of change was very large (over 15 points per cell the first couple of times) but after 10 or so short data logs and tuning updates it's working its way down.

I still need to set up the afterstart enrichments but it now drives around the stoich region


I'm guessing installing my 450cc injectors from stock will be weird since the REQ_FUEL is not properly calculated. But I'm guessing just halving the REQ_FUEL (450/230=.48 ish) then re-scaling the VE table to get a resolution close to the 250 upper limit should work right?
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