The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support STM Tuned
Please Support ExtremePSI

2G Crank no start - All vitals present but wont run!

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

germangorrilla

Probationary Member
7
0
Apr 5, 2018
Clinton, Washington
Recently picked up 95 Talon TSI as a project car. The car had a blown head gasket about 5-6 years ago (hasn't been registered since 2012) and hasn't run since. Previous owner took their time replacing the HG with her father, and after the HG was replaced it wouldn't start. They replaced lots of sensors, the engine wiring harness, ecu (then sent both ecus to ecmtuning and had capacitors replaced), removed the aftermarket alarm, and more. First thing i did was drain the old fuel and put new fuel in. The car is mostly stock aside from being bored .040 over, forged pistons, balance shafts deleted, and an ebay 16G turbo.

This thing will crank and fire, rev to about 1000-1500 and immediately die. It maintains fuel pressure (45 psi), spark, injector pulse, and rpm signal the entire time while it cranks, starts, revs and dies. Cam timing is dead on, I replaced the cam sensor on a hunch because it wasn't replaced before. I have tried both ECUs and get the same results. After it fires I can crank it forever and it will never fire again unless I unplug injectors, then its fire then rev then it runs out of fuel, then plug them back in and it'll fire and die and I can crank it till the battery dies. It will also fire and rev and die on starting fluid. It definitely seems and smells like it is getting overfueled. It has a stock ecu, stock injectors, plugs, wires, etc. I cant find a reason for it to be overfueling. Has OK compression, not great from my experience 120lbs (this is the lowest) should be enough to fire and run.

I am stumped on this thing so any thoughts would be greatly appreciated.
 
If it's running way rich, it could be a metering problem with the MAF, an intake leak like chrysler kid suggested, or it could be a coolant or intake temperature sensor reporting bad numbers (previous owner said they were replaced, but I don't trust previous owners to not make mistakes).
 
Recently picked up 95 Talon TSI as a project car. The car had a blown head gasket about 5-6 years ago (hasn't been registered since 2012) and hasn't run since. Previous owner took their time replacing the HG with her father, and after the HG was replaced it wouldn't start. They replaced lots of sensors, the engine wiring harness, ecu (then sent both ecus to ecmtuning and had capacitors replaced), removed the aftermarket alarm, and more. First thing i did was drain the old fuel and put new fuel in. The car is mostly stock aside from being bored .040 over, forged pistons, balance shafts deleted, and an ebay 16G turbo.

This thing will crank and fire, rev to about 1000-1500 and immediately die. It maintains fuel pressure (45 psi), spark, injector pulse, and rpm signal the entire time while it cranks, starts, revs and dies. Cam timing is dead on, I replaced the cam sensor on a hunch because it wasn't replaced before. I have tried both ECUs and get the same results. After it fires I can crank it forever and it will never fire again unless I unplug injectors, then its fire then rev then it runs out of fuel, then plug them back in and it'll fire and die and I can crank it till the battery dies. It will also fire and rev and die on starting fluid. It definitely seems and smells like it is getting overfueled. It has a stock ecu, stock injectors, plugs, wires, etc. I cant find a reason for it to be overfueling. Has OK compression, not great from my experience 120lbs (this is the lowest) should be enough to fire and run.

I am stumped on this thing so any thoughts would be greatly appreciated.
Datalogging is one ofof the easiest ways to spot sensor issues also.
 
You say it dies on starting fluid, and you think it's running way rich. What happens if you disconnect the injectors, and try the starting fluid? That would prevent the computer from dumping fuel, and if you could coax the engine into running longer it'd at least tell you if your rich condition is related to your stalling issue.
 
Without a log we're all guessing, but with a log it improves to educated guessing.

Unfortunately it does not have dsmlink yet, so a log isnt possible :(

You say it dies on starting fluid, and you think it's running way rich. What happens if you disconnect the injectors, and try the starting fluid? That would prevent the computer from dumping fuel, and if you could coax the engine into running longer it'd at least tell you if your rich condition is related to your stalling issue.

It does run slightly longer on starting fluid with the injectors unplugged, but still dies after a few seconds
 
Replace the coolant temp sensor, also unplug the vacuum line from the fuel pressure regulator in case the regulator is leaking into the vacuum line.
 
It does run slightly longer on starting fluid with the injectors unplugged, but still dies after a few seconds

Well, if you can't keep the engine running even with repeated applications of starting fluid, that would seem to suggest your problem is not fuel metering; that leaves air, compression, spark, and timing.

Air seems unlikely because unless it's immediately getting smothered, it should run with air leaks. Still, I'd do a boost leak test to eliminate another variable. Have you tried running the car with the MAF unplugged, effectively putting the car into it's speed density backup mode? Probably unnecessary since the car wont run even on starting fluid, but worth a check.

120psi is low (likely a cold number, since the engine wont run to get up to operating temperature), but as you say it should be enough for the engine to fire and run.

Spark would seem likely. What plugs do you have in the car? You say you're getting spark. How did you test? Was the spark strong enough to jump a large gap? I like to use a test light to ground and see how far of a gap the spark will jump; should be >=1".

I also didn't see you mention anything about your crank sensor. According to the shop manual, the ECU uses signals from both the crank sensor and cam sensor to determine timing on a DSM. Have you checked it's function (power, ground, signal)? Cranksensor should output a 0-5v square wave, iirc, which would produce an average of about 2.50v on a multimeter.

Have you checked that the ECU is putting out a good 5v reference? I'd check for it at the TPS, and the CTS to confirm that both legs of the reference circuit are good. Might have a bad sensor shorting the whole thing to ground. Really, that should cause a no start, not a start and stall, but still worth a quick check. If you had a lab scope, checking the cam/crank relationship would be ideal.

If I were a betting man, and we're all just guessing at this point, your symptoms, for whatever reason, make me think something electrical. My guess would be something heats up when it sees load, creates an open internally, causing the car to die, and not restart until the component has cooled sufficiently, explaining why sometimes it'll start, stall, and it wont start again immediately after.

One last question: on the occasions when it starts and revs to 1500 (probably res that high because of fast idle, but the ECU could be reading throttle input), does it seem like it's running normally, or does it seem rough?
 
Last edited:
Well, if you can't keep the engine running even with repeated applications of starting fluid, that would seem to suggest your problem is not fuel metering; that leaves air, compression, spark, and timing.

Air seems unlikely because unless it's immediately getting smothered, it should run with air leaks. Still, I'd do a boost leak test to eliminate another variable. Have you tried running the car with the MAF unplugged, effectively putting the car into it's speed density backup mode? Probably unnecessary since the car wont run even on starting fluid, but worth a check.

120psi is low (likely a cold number, since the engine wont run to get up to operating temperature), but as you say it should be enough for the engine to fire and run.

Spark would seem likely. What plugs do you have in the car? You say you're getting spark. How did you test? Was the spark strong enough to jump a large gap? I like to use a test light to ground and see how far of a gap the spark will jump; should be >=1".

I also didn't see you mention anything about your crank sensor. According to the shop manual, the ECU uses signals from both the crank sensor and cam sensor to determine timing on a DSM. Have you checked it's function (power, ground, signal)? Cranksensor should output a 0-5v square wave, iirc, which would produce an average of about 2.50v on a multimeter.

Have you checked that the ECU is putting out a good 5v reference? I'd check for it at the TPS, and the CTS to confirm that both legs of the reference circuit are good. Might have a bad sensor shorting the whole thing to ground. Really, that should cause a no start, not a start and stall, but still worth a quick check. If you had a lab scope, checking the cam/crank relationship would be ideal.

If I were a betting man, and we're all just guessing at this point, your symptoms, for whatever reason, make me think something electrical. My guess would be something heats up when it sees load, creates an open internally, causing the car to die, and not restart until the component has cooled sufficiently, explaining why sometimes it'll start, stall, and it wont start again immediately after.

One last question: on the occasions when it starts and revs to 1500 (probably res that high because of fast idle, but the ECU could be reading throttle input), does it seem like it's running normally, or does it seem rough?

I have tried with the MAF unplugged - no change as far as the way it runs or how long. The 120 Psi was the lowest i saw, but it was also on the cylinders with the most fuel in them - so fuel washing down the walls was likely an issue there. The crank sensor was supposedly replaced by the PO and it looks new to me, but i will do some testing on it to be sure and make sure there's a 5v reference. Also, when it does start and rev to 1500 runs smooth then shuts down as if i switched off the key, i haven't found a way to keep it running any longer.
 
I have tried with the MAF unplugged - no change as far as the way it runs or how long. The 120 Psi was the lowest i saw, but it was also on the cylinders with the most fuel in them - so fuel washing down the walls was likely an issue there. The crank sensor was supposedly replaced by the PO and it looks new to me, but i will do some testing on it to be sure and make sure there's a 5v reference. Also, when it does start and rev to 1500 runs smooth then shuts down as if i switched off the key, i haven't found a way to keep it running any longer.

The fact that it's running smooth until it dies would again push me towards electrical. What does your tacometer do during all this?

The spark system is pretty simple on these things: iirc, the ECU uses the crank signal in relation to the cam signal to do initial orientation on where in the firing order the engine is, then uses the cam sensor for ignition timing on 2&3. The signal is inverted in the PTU for 1&4. PTU also provides RPM signal to the ECU and cluster.

Man, I wish you were local; I'd love to get my hands on this one--an interesting mystery. Still, there's far too many variables here with all the tinkering the previous owner did to diagnose remotely/blindly... it's hard to proceed without scan data. You'll need to find yourself a scanner that will allow you to view live data.

A longshot: does the car die when you release the key from START to RUN?
 
The fact that it's running smooth until it dies would again push me towards electrical. What does your tacometer do during all this?

The spark system is pretty simple on these things: iirc, the ECU uses the crank signal in relation to the cam signal to do initial orientation on where in the firing order the engine is, then uses the cam sensor for ignition timing on 2&3. The signal is inverted in the PTU for 1&4. PTU also provides RPM signal to the ECU and cluster.

Man, I wish you were local; I'd love to get my hands on this one--an interesting mystery. Still, there's far too many variables here with all the tinkering the previous owner did to diagnose remotely/blindly... it's hard to proceed without scan data. You'll need to find yourself a scanner that will allow you to view live data.

A longshot: does the car die when you release the key from START to RUN?

It sounds like you might be thinking ignition switch - something I haven't thought of, but does make sense. After its been flooded it will cough and fire while cranking (could be 5-10 seconds) until it eventually clears enough fuel and does start and run smooth, but then dies again. How would you recommend testing the ignition switch? I do have a small scan tool that I can view live data on, what should I be looking at and what should I be looking for?
 
It sounds like you might be thinking ignition switch - something I haven't thought of, but does make sense. After its been flooded it will cough and fire while cranking (could be 5-10 seconds) until it eventually clears enough fuel and does start and run smooth, but then dies again. How would you recommend testing the ignition switch? I do have a small scan tool that I can view live data on, what should I be looking at and what should I be looking for?

Looking at a wiring diagram for a '96 Talon, easiest (most accessible) way to test the ignition switch would be to backprobe pin 3 at the coil connector (black with white wire), which gets its power from the ignition switch. You should see battery voltage here with key on engine off. I would next move the ignition switch slowly through it's range to check for any drops in voltage that would indicate a dead spot. Be mindful of system voltage dropping when the starter engages.

As for a data logger. First thing I'd look at is your short and long term fuel trims (edit: actually, thinking about it, fuel trims might be fruitless since the engine isn't running long enough to get into closedloop and adjust trims). You want to confirm or deny that it's fuel causing the engine to flood out so you have direction. If those seem fine, next step would be to look for direction by recreating the problem while watching vital ECU inputs: crank, cam, IAT, CTS, MAF, TPS.

Your STFT, and LTFTs should be near 0%. With the engine cranking/running you should see cam and crank sensors cycling between 0v and ~5v, your MAF responding to airflow by increasing frequency, and your IAT, CTS, and TPS should be giving sane values that match conditions.

Post your data here and we'll let you know if anything seems out of wack.
 
Last edited:
Everything you mention really sounds like the crank or cam sensor sense yours is a 95 it has both. The car does not "look" for the signal from them for a moment once started. Then if there's no signal the car will shut off. Even if both are new it can be positioned wrong or hit the cam gear. I would suggest searching for symptoms of bad CAS/CPS, and possibly putting on the 1g style instead.
Also, I believe that there is 2 plugs that are identical near the cam sensor I believe one time I plugged it into the wrong connector.
 
Last edited:
Looking at a wiring diagram for a '96 Talon, easiest (most accessible) way to test the ignition switch would be to backprobe pin 3 at the coil connector (black with white wire), which gets its power from the ignition switch. You should see battery voltage here with key on engine off. I would next move the ignition switch slowly through it's range to check for any drops in voltage that would indicate a dead spot. Be mindful of system voltage dropping when the starter engages.

As for a data logger. First thing I'd look at is your short and long term fuel trims (edit: actually, thinking about it, fuel trims might be fruitless since the engine isn't running long enough to get into closedloop and adjust trims). You want to confirm or deny that it's fuel causing the engine to flood out so you have direction. If those seem fine, next step would be to look for direction by recreating the problem while watching vital ECU inputs: crank, cam, IAT, CTS, MAF, TPS.

Your STFT, and LTFTs should be near 0%. With the engine cranking/running you should see cam and crank sensors cycling between 0v and ~5v, your MAF responding to airflow by increasing frequency, and your IAT, CTS, and TPS should be giving sane values that match conditions.

Post your data here and we'll let you know if anything seems out of wack.

Haven't been spending much time on it lately. Testing the ignition switch revealed it was OK. I picked up some used injectors (were in better shape and resistances were closer between them), results were a very slight improvement immediately after install, now same thing as before. It is getting drowned in fuel - oil is discolored and about a half quart overfull now. Resistances on the resistor pack were all within spec, disconnected the return line to the tank and directed a hose off the FPR into a container - there was not excessive fuel getting past the FPR and there was no change in how long it ran. I've checked the clearances on the CKP and the CMP sensors relative to their trigger wheels and cleaned them. All data values on my scan tool were of sane values.

So what could be causing it to dump fuel through the injectors? I've never run into anything like this and completely stumped
 
Perform a boost leak test. For all we know the car could be missing a throttle body gasket and your dumping fuel from a big vacuum leak.

Vacuum has to be constant through the piping or the mass air flow sensor calibrations are completely off.

Both sides of the gasket actually have a small amount of silicone on them thanks to the PO, I'll be taking it apart to clean all that off. From my experience, vacuum leak will cause a lean condition as long as it is in in open loop fueling, like when first starting. The MAF reads less air passing by it because there is air entering the system after it and the ecu only adds fuel for the little amount of air the MAF is seeing. Once in closed loop, the ECU will take the O2 sensors input and add fuel accordingly, which could create a rich mixture.

Coolant temp sensor... If you can read it I bet it shows -40dg.

The ECT sensor has been replaced already and reads correctly

Thanks for all the help everyone! Haven't gotten it figured out yet, keep throwing me ideas because im out LOL
 
What about thr mfi or mpi relay both are the same its just how you want to interpret that. Its located under the radio on the passenger side. If you have a manual or auto. Trans they will be different. But i have a pic of what it looks like the diagram should help also.
Good luck
 

Attachments

  • Screenshot_20180630-150215.jpg
    Screenshot_20180630-150215.jpg
    85.7 KB · Views: 121
  • Screenshot_20180630-151333.jpg
    Screenshot_20180630-151333.jpg
    109.9 KB · Views: 120
Gorrilla did you get your issue resolved? I'm having the same issue with my 95 GS-T after swapping the clutch. Turns over, acts like it wants to fire (gets spark), floods,won't start. Nothing else was changed so I'm curious if you found a solution.
 
Guys I would check two things, 1 compression test. 2 check ohm reading on temp sensor and verify it is in spec. Then check other things.

If the car is flooded it won't like to start. If the temp sensor thinks car is frozen will flood engine. That is one possibility.

I checked all sensors and fuel flow even used noid lights to check fuel injector firing just to figure out I had loss of compression due to hg failure.
 
Guys I would check two things, 1 compression test. 2 check ohm reading on temp sensor and verify it is in spec. Then check other things.

If the car is flooded it won't like to start. If the temp sensor thinks car is frozen will flood engine. That is one possibility.

I checked all sensors and fuel flow even used noid lights to check fuel injector firing just to figure out I had loss of compression due to hg failure.
yep this happened to me. Cold outside ,car cranks and would not start for nothing.Bad connection on temp sensor resulting in faulty neg reading so car would not start. When I hit the wires the ecm link showed me intermittent readings. Re spliced fixed the wires connected to my temp sensor plug and she starts right up.

Coolant temp sensor... If you can read it I bet it shows -40dg.
Yep
 
Last edited by a moderator:
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top