2G Talon crank no start only when MAF plugged in?

[7ahmir]

To give some background about two days before this issue occurred I had been going in and removing rust spots below my battery mount and had just finished painting over with some rust prevention paint. Once I was done I placed the battery back in to see if it’ll run, but unfortunately… I had dropped the battery ever so slightly and a corner landed on some wires that run around the engine..

When I had went to plug in my battery and crank over the car for the first time, it decided to turn over as if it were going to start, but immediately died after. At first glance in my head I’m saying, ”alright I’ve definitely F’d up a wire from that.” But while trying to inspect what could be wrong, I wanted to try starting it with the MAF sensor unplugged (I had just replaced it the same day) and lo and behold, it turned over . I’m fairly new the the 4g63 platform as I’m coming from a 420a Eclipse, but I’ve gone through a few of the forums and done some research on here and dsmtalk, but I haven’t found an answer I find sensible (maybe that’s the problem). Fuel system is priming, spark plugs were just replaced and gapped, new MAF sensor, cleaned my IAC, tried a jump start, and I’m currently about to pull my injectors and check them.

My big question is, are there majors things I’ve overlooked? I plan on checking for boost leaks, but the car ran and drove fine before I started doing rust repairs… I’m worried it’s electrical, but I’m willing to take on the job. Before this I was tracing an idle surge problem, so I had cleaned out the IAC and replaced the MAF sensor, but now this… welcome to DSM life ig . Also please skip the ridicule I might be stupid but I'm willing to learn!

I should add… it turns over when MAF is unplugged but obviously runs rough.

 

[pauleyman]

You're not exactly clear. Are you saying it now doesn't want to crank at all? Turn key and it does nothing at all? Or does it always crank just doesn't start?

 

[7ahmir]

You're not exactly clear. Are you saying it now doesn't want to crank at all? Turn key and it does nothing at all? Or does it always crank just doesn't start?

Always cranks but does not start w/ maf plugged in. It sort of turns over as if it’s about to start for a literal second then dies (I can feel it because my mounts need replaced).

I meant to edit this post a few hours ago, but I had been reading up on possible CAS symptoms. Along with a few other possible failures, I was checking some boxes. I apologize, I made this post in a panic. I didn’t really articulate my problem to the fullest.

I had purchased this 95 TSi a few weeks ago knowing that it ran a little rough (as in it bogged and jerked at low rpm, would also die at idle on cold start). The car ran and drove from the seller’s place to my lot with only minor inconvenience. The car had an idle surge problem when warming up, and I had done some research on it with a lot of recommendations to check my MAF sensor, my IAC and my BISS adjustments. After going through those three, I determined at least that the MAF sensor was faulty. The car would run WITH AND WITHOUT the MAF plugged in. As for the IAC I only had time to clean it and reinstall (I am researching before i know if I should replace it). I touched up my TB and wanted to mess with the BISS but I don’t have DSMLink. I had just been doing fluid changes on the car until I started working on the mechanical aspects, so those three tasks came before this.

Now, following the original post, I’m going back in to recheck my spark, starting with fuses, plugs, voltage on connectors, and most importantly I want to check that CAS.

I apologize for the paragraph, but a point in the right direction would be greatly appreciated

 

[jdxnc]

Sound like burnt sensor ground trace in the ECU. When any of the sensor or wiring get shorted out due to wire damage it usually burns the ECU sensor ground. When this happens the car will think it's -40F and flood the hell out of the engine. A good sign of this being the case is the car will start with the MAF unplugged.

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[7ahmir]

Sound like burnt sensor ground trace in the ECU. When any of the sensor or wiring get shorted out due to wire damage it usually burns the ECU sensor ground. When this happens the car will think it's -40F and flood the hell out of the engine. A good sign of this being the case is the car will start with the MAF unplugged.

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This’ll be something I check!

I had intentions of investing in a new/used EPROM ECU because I want to eventually run DSMLink. Is there any hypothetical resolution to this if that so happens to be my problem?

 

[pauleyman]

You kind of already stated your issue. You dropped the battery and likely damaged wires. If it doesn't really run that much different than before then go about diagnosis as normal. Fix leaks, check sensors etc.
How exactly did you determine mas was bad? Plugging and unplugging is not an adequate test.

 

[7ahmir]

You kind of already stated your issue. You dropped the battery and likely damaged wires. If it doesn't really run that much different than before then go about diagnosis as normal. Fix leaks, check sensors etc.
How exactly did you determine mas was bad? Plugging and unplugging is not an adequate test.

If that’s the case than I still have quite to learn. I was told that’s how it was done, but if that’s the incorrect process of determination I will have to do more research! I already put in a new one anyway, but I’ll be keeping any parts I pull. Thank you for informing me. As for the wire problem, I’m gonna be borrowing my friend’s multimeter and visually inspecting wire damage.

Also as mr. jdxnc I will be inspecting my ECU too. I have the time and patience to figure out these cars, so please if I’m misinformed don’t hesitate to call me on it!

 

[jdxnc]

If you find the ECU ground burnt, I would bet money on this, you first need to find the cause, it sent 12v through the ground somewhere to cause it. Once that's done, you can run a jumper wire on the back side of the PCB to bridge the burnt spot.

 

[7ahmir]

Wow so turns out it already had ECMLink as it is an EPROM ECU. With that now known, is there any type of log I can pull off the ECU? I don’t have an OBDII adapter cable, but that’s not hard in the slightest to get.

I guess my big question would be if there’s any way to read the crank no start off ECMLink? I’m not too educated on tuning, but why not jump into it while we’re in the present!

There are a few concerning points I noticed while inspecting though. My vision isn’t the best but I cannot tell if the third picture is corrosion or burns.

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[jdxnc]

I don't see any obvious burns. This is a little suspicious though

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You can buy the cable here: https://www.ecmtuning.com/product_info.php?cPath=26&products_id=42

Then you'll be able to log while starting/running the car. These ECU's don't log on their own, it needs to be connected to a PC.

 

[7ahmir]

I don't see any obvious burns. This is a little suspicious though

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You can buy the cable here: https://www.ecmtuning.com/product_info.php?cPath=26&products_id=42

Then you'll be able to log while starting/running the car. These ecu's don't log on their own, it needs to be connected to a PC.

Sounds like a plan. I’ve held enough of your time and thank you for your help! Hopefully this pushes me towards the right direction! Have a great night man!

 

[steve]

Those little bubbles are just the conformal coating. Nothing to worry about.

Get the 2G USB Datalogging Cable From ECMTuning and download the software https://www.ecmtuning.com/downloads.php Then you can find out how your ECU is currently configured and look at the various sensor values to see if they are working.

It helps to also have a accurate current inventory of any modifications to compare to how the ECU is configured.

 

[7ahmir]

Those little bubbles are just the conformal coating. Nothing to worry about.

Get the 2G USB Datalogging Cable From ECMTuning and download the software https://www.ecmtuning.com/downloads.php Then you can find out how your ECU is currently configured and look at the various sensor values to see if they are working.

It helps to also have an accurate current inventory of any modifications to compare to how the ECU is configured.

Dually noted. It does have a couple of goodies in it, so I’m gonna be making a list as soon as I get that cable

 

[7ahmir]

Those little bubbles are just the conformal coating. Nothing to worry about.

Get the 2G USB Datalogging Cable From ECMTuning and download the software https://www.ecmtuning.com/downloads.php Then you can find out how your ECU is currently configured and look at the various sensor values to see if they are working.

It helps to also have an accurate current inventory of any modifications to compare to how the ECU is configured.

I’ve taken the time to take a video of what the crank no start sounds like. Today I’m going in and testing all my fuses and tracing some ground wires, any specific things I should look for?

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[jdxnc]

Almost sounds like not enough fuel pressure to keep going.

 

[7ahmir]

Almost sounds like not enough fuel pressure to keep going.

At first, I thought the same thing. So I changed out my fuel filter, didn’t find any suspicious gunk. I’ve been struggling to get the fuel rail off to check injectors, so that’s on the bucket list. FPR was sitting at a consistent 50psi when I ran the car with no MAF. Also this might sound funny, but the car used to prime fuel in accessory mode before I unplugged the battery for the first time. I read up on this and from what I’m hearing that’s usually an error in the ECU to possibly disregard. It primes on crank though. I’ve thought about taking it to a shop to see if an inspection from a professional comes back with any news, but I’m at a lost.

Me and a couple buddies are gonna perform a boost leak and compression test this Saturday also.

Is it possible that unplugging the battery cause the ecu to completely reset? ECMLink and all?

 

[jdxnc]

ECMLink has a feature to make the pump prime at key on for a set amount of time. You have a V3 chip which MOST of the time retains the tune after a power loss, however a short or other strange electrical situation can make it revert to stock and loose the tune. This may very well be the case seeing as you had the initial incident. This would wipe out the injector settings, cam/crank profile, airflow settings, etc making the car not start. You need that cable ASAP.

Now with this new info about the prime no longer working, it's quite possible the tune is lost.

 

[7ahmir]

ECMLink has a feature to make the pump prime at key on for a set amount of time. You have a V3 chip which MOST of the time retains the tune after a power loss, however a short or other strange electrical situation can make it revert to stock and loose the tune. This may very well be the case seeing as you had the initial incident. This would wipe out the injector settings, cam/crank profile, airflow settings, etc making the car not start. You need that cable ASAP.

Now with this new info about the prime no longer working, it's quite possible the tune is lost.

Interesting, could that also be why the car does run with the MAF sensor unplugged? Like it’s reverting back to using the CAS to keep the car running? In that case would it be more efficient to consult a tuner before a mechanic? Denver is plentiful of DSM tuners as I’ve come to see

 

[jdxnc]

Interesting, could that also be why the car does run with the maf sensor unplugged? Like it’s reverting back to using the cas to keep the car running? In that case would it be more efficient to consult a tuner before a mechanic? Denver is plentiful of dsm tuners as I’ve come to see

When the MAF is unplugged it's not getting an air reading, just using a base value, so it's pulling a lot of fuel if my memory is correct. So if the car has larger than stock injectors, it would be flooding the crap out of itself if the tune reverted to stock, so removing the MAF signal would actually help.

You need the cable to do a basic setup and check over of the ECU before you can do anything else. Even a tuner will need the cable.

 

[7ahmir]

When the MAF is unplugged it's not getting an air reading, just using a base value, so it's pulling a lot of fuel if my memory is correct. So if the car has larger than stock injectors, it would be flooding the crap out of itself if the tune reverted to stock, so removing the MAF signal would actually help.

You need the cable to do a basic setup and check over of the ECU before you can do anything else. Even a tuner will need the cable.

Well, I think I’ve just made it worse… I decided I’d try doing a hard reset on the v3 per the ecmlink guide, and now I think my starter went out… I’ve went from an idle surge to a crank no start to a no crank no start. it seems the more I touch it the more it falls apart currently

v3hardreset [ECMTuning - wiki]

www.ecmtuning.com

 

[CanadianTalonTC]

Well, I think I’ve just made it worse… I decided I’d try doing a hard reset on the v3 per the ecmlink guide, and now I think my starter went out… I’ve went from an idle surge to a crank no start to a no crank no start. it seems the more I touch it the more it falls apart currently

v3hardreset [ECMTuning - wiki]

www.ecmtuning.com

What modifications are done to this car? I checked your profile and didn't see one filled out, unless I missed it in this thread.

If you have anything other than stock injectors or really any mods at this point just put the key down and wait for the cable to arrive. Best thing you can do is do your best to inventory everything that has been changed on the car so you can input those into link once it shows up.

I'm assuming you have a wideband in there as well? Which kind so we can get it setup for you in ECMLink. You might have to trace cables to see what pinout it is and such for logging.

Have you charged your battery since this started? Cranking takes a lot of juice.

 

[7ahmir]

What modifications are done to this car? I checked your profile and didn't see one filled out, unless I missed it in this thread.

If you have anything other than stock injectors or really any mods at this point just put the key down and wait for the cable to arrive. Best thing you can do is do your best to inventory everything that has been changed on the car so you can input those into link once it shows up.

I'm assuming you have a wideband in there as well? Which kind so we can get it setup for you in ECMLink. You might have to trace cables to see what pinout it is and such for logging.

Have you charged your battery since this started? Cranking takes a lot of juice.

Yeah I just picked up the car fairly recently so I haven’t made a profile for it.
It’s a 95 2ga talon awd w/

What I do know I have:
-Aftermarket FMIC setup
-Stock BOV vented to atmosphere
-ARP headstuds
-Wiseco/eagle pistons and rods (I don’t know the ratios)
-HKS cam shafts (I believe 272’s if I’m correct)
-aeromotive afr gauge with braided fuel lines
-stock turbo (I think) w/boost controller
-dsmlink V3 socketed ecu
-iridium Bpr6eix spark plugs
-4inch DP
-aluminum koyorad radiator w/ mishimoto slim fans
-magnus fuel rail
-stock headers/stock intake manifold
-stock throttle body
-upgraded clutch (I don’t know what brand/model)
-lsd in the rear
-ball cooler (nice)
-stock turbo intake that was plugged from the bov

WHAT I STILL NEED TO CHECK:
-I believe it’s got an upgraded fuel pump, likely walboro bc it wines a lot louder than stock
-injectors are definitely not stock but I need to check cc’s
-wideband I believe is connected to this “glow shift” gauge

It’s had some headwork, but I believe it was just from the camshafts. I could’ve checked my injectors sooner if the previous owner didn’t tighten the rail with the force of god. Tracing that wire and those injectors is top priority till I get that cable though. shouldn’t be hard since I already have the ecu and lower dash pulled


-once again thank you for your guys’ help I’m grateful these forums exist in the first place!

Overall the setup didn’t run the worst when I got the car, it’s when I started touching things that the bomb went off

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[7ahmir]

Yeah I just picked up the car fairly recently so I haven’t made a profile for it.
It’s a 95 2ga talon awd w/

What I do know I have:
-Aftermarket FMIC setup
-Stock BOV vented to atmosphere
-ARP headstuds
-Wiseco/eagle pistons and rods (I don’t know the ratios)
-HKS cam shafts (I believe 272’s if I’m correct)
-aeromotive afr gauge with braided fuel lines
-stock turbo (I think) w/boost controller
-dsmlink V3 socketed ecu
-iridium Bpr6eix spark plugs
-4inch DP
-aluminum koyorad radiator w/ mishimoto slim fans
-magnus fuel rail
-stock headers/stock intake manifold
-stock throttle body
-upgraded clutch (I don’t know what brand/model)
-lsd in the rear
-ball cooler (nice)
-stock turbo intake that was plugged from the bov

WHAT I STILL NEED TO CHECK:
-I believe it’s got an upgraded fuel pump, likely walboro bc it wines a lot louder than stock
-injectors are definitely not stock but I need to check cc’s
-wideband I believe is connected to this “glow shift” gauge

It’s had some headwork, but I believe it was just from the camshafts. I could’ve checked my injectors sooner if the previous owner didn’t tighten the rail with the force of god. Tracing that wire and those injectors is top priority till I get that cable though. shouldn’t be hard since I already have the ecu and lower dash pulled


-once again thank you for your guys’ help I’m grateful these forums exist in the first place!

Overall the setup didn’t run the worst when I got the car, it’s when I started touching things that the bomb went off

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Radiator was wired to run constantly and the aforementioned “glow shift” gauge has tubing from the firewall, past the battery, all the way to the turbo

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[CanadianTalonTC]

BOV needs to be recirculated with a MAF. Just do it, will work so much better. I know there is some setting to compensate but it isnt worth it, just run SD if you want that.

It's too bad about the reset of the tune, it probably had valuable information in it.

Rads are probably wired on all the time cause it overheats with the FMIC. Link has a button to do it though .

Definitely work on finding out the injectors. Might not be a bad idea to pull the valve cover and see what is in there as it might affect your tuning a but. Are you plan on getting it done or doing it yourself? You'll also be able to join the ecmlink forums so email them about that.

Also I forgot to ask why 50psi fuel pressure? Set it to stock base pressure for ease of tuning.

Accurate boost source but not my choice .

 

[7ahmir]

BOV needs to be recirculated with a MAF. Just do it, will work so much better. I know there is some setting to compensate but it isnt worth it, just run SD if you want that.

It's too bad about the reset of the tune, it probably had valuable information in it.

Rads are probably wired on all the time cause it overheats with the FMIC. Link has a button to do it though .

Definitely work on finding out the injectors. Might not be a bad idea to pull the valve cover and see what is in there as it might affect your tuning a but. Are you plan on getting it done or doing it yourself? You'll also be able to join the ecmlink forums so email them about that.

Also I forgot to ask why 50psi fuel pressure? Set it to stock base pressure for ease of tuning.

Accurate boost source but not my choice .

I just gotta order some new gaskets and that valve cover is coming off! I’ve been itching to open this thing up also definitely needa rout the BOV though, hell what if that aided to my original issue!

The 50psi was from them running 20 pounds of boost I believe. Me personally, i don’t need 20psi of boost to have fun in this car.

To save some cash I’ve been reading up on ecmlink’s page for the past 2 day nonstop, but if the time comes and I feel I can’t do it myself, I know some tuners in aurora Colorado with some experience.

I’m currently looking to find the previous owner that built the car. I found one of his friends, so I’m on a good start. Hopefully he’s got some old files I could reference for tuning