2G No Start. Sensor Voltage and Harness Swap

[joshuah]

I'm having serious trouble getting my 95 Talon to start. As of now crank no start due to no spark.

I run voltage test on all the sensors and get 12v on all except TPS has 5v, CAM has 5v on one wire 12v on another, coil trigger power wire blk/w stripe has 12v the PTU has 12v on 3 wires 8v on 1.

The ECU right now is a black box, car is a 95 Talon. I have a EPROM ECU just cant afford ECMLink yet.

Just within last few months I had it tore down and put new rotating assembly in, forged H beam connecting rods, Nippon scat pistons, OEM crank, king bearing set, ARP 2000 cap bolts, ARP main studs, balance shaft delete, new valves and valve seals, ARP head studs, Cometic MLS head gasket, and HKS timing belt.

Please help I have no more knowledge about what to do.

 

[miliman13]

You measured the input voltage but did you measure the output voltage ?

TPS and many other sensors use 0-5v range do that’s normal

If you don’t get spark ️ check your -grounds - coils - TPU - ect

Only real way is to have spares , not always do failed components provide out of spec values.

 

[joshuah]

Well I'm not too sure but like for instance the plug for the crank shaft position sensor gets 5v on one pin and 12v on another pin

Also I'd like to note that crank and cam shaft position sensors are new.

 

[luv2rallye]

The CAS sensor (on intake cam) will always have +12v supply voltage on the red wire. The blue-red wire is the sense wire and is pulled up to +5v which is why you see that voltage there. However when the magnets pass by, it briefly goes to near zero volts (which is the position signal).

 

[chrysler kid]

I dunno I’m late to comment,

Are you running a 2ga cam sensor or a 2gb cam sensor, they’re totally different and the ECU is dependent on that certain sensor specific to the year model.

 

[steve]

The wires going to/from the MPI or ignition switch get 12v the wire connecting to ECU pin 81 get 5v. Do you get a CEL turned on for 5 seconds when you turn the ignition on?

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[miliman13]

Hey @steve im curious if any of the diagrams you just posted are about the big blue connector~terminal looking thing behind the radio in the 2G.
I know those connect directly to the body/Engine harness but i don't know what those connectors are, I'm trying to get an early idea since I have to re-assemble a bare shell.

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[steve]

Hey @steve im curious if any of the diagrams you just posted are about the big blue connector~terminal looking thing behind the radio in the 2G.
I know those connect directly to the body/Engine harness but i don't know what those connectors are, I'm trying to get an early idea since I have to re-assemble a bare shell.

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I have no idea and can't see the wires or how many pins are there. Perhaps look at the configuration diagrams and compare everything in the console location with what you have.

 

[joshuah]

Do you get a CEL turned on for 5 seconds when you turn the ignition on?

Yes it comes on then goes out

 

[joshuah]

So my DSM has been down for 2 months at least with a crank no start.

I've replaced, crank sensor, cam sensor and ignition coil, ignition control module, fuel pump, MPI/fuel pump relay fuel filter , spark plugs and wires, IAC , TPS and came to find out that my engine harness had bad shorts because all my 5v reference wires had 12v constant with ignition on.

Since, I've bought a decent engine harness off a guy who said it was from his 96, did not mention it was an automatic. I've looked for threads and discussions on here to make sure I have wired the MPI relay and starter relay correctly but nothing here had what I was looking for. And on the engine everything is plugged in but there was something that was cut off and the I only thing I think it could be is a automatic transmission plug.

Every wire on the MPI that was the same color I wired to them, except one wire one was blk/wht and other one blue, so I wired them together. But 3 red wires how am I to know which ones go the other reds ones.

Please help me my car has not ran for 2 months and it has compression 179 on all 4 and timing is good

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[jesse12345]

Maybe this will help but when I used an auto harness on my manual I had to bypass the neutral safety. You have to cut and twist 2 wires together, here's how mine looks. I used a 97 harness though so I'm not entirely sure if the wires are the same.

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[joshuah]

Maybe this will help but when I used an auto harness on my manual I had to bypass the neutral safety. You have to cut and twist 2 wires together, here's how mine looks. I used a 97 harness though so I'm not entirely sure if the wires are the same.

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Where is that plug located

 

[jesse12345]

Here is a picture of my auto. It should be on the transmission side under the hood.

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Picture sucks, but there should be quite a few plugs just hanging out by or on the transmission if there not all cut off.

 

[joshuah]

Maybe this was where that plug was i dont know. These wires are between my bov and the head

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[jesse12345]

It very well could be. I did find this picture you could see if the wires match in the bundle. It's been at least 4 years since I did this so the memory is a little foggy.

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[joshuah]

I'm done trying to get this car to start . I've invested too much time and money and its never gonna start again obviously. No matter what o replaced every thing 2 fuxkin times and at this point this car will be going to scrap yard.

 

[joshuah]

Thanks bro I got it cranking but still wont start

 

[jesse12345]

So now you got it to crank but your still back to the no start? It's unfortunate that the harness you did get was so cut up. Have you checked for fuel and spark? I'm going to assume you have but just checking.

Another question, did the car just randomly die before you swapped this harness? Is that the reason you swapped it?

 

[joshuah]

Yes it was running pretty good after I had put new valves in . 180 compression on all 4 cylinders. I literally pulled in garage after driving to get tax waiver and next day crank no start. I replaced all sensorz iac, icm, crank and cam sensors ignition coil and fuel pump still wouldn't start. I noticed all my 5v reference wires were getting 12 volts and I tried finding it in harness loom.....then bought this one and still cranks no start and rpm gauge doesn't move while crankin

 

[pauleyman]

Im done trying to get this car to start . I've invested too much time and money and its never gonna start again obviously. No matter what o replaced every thing 2 fuxkin times and at this point this car will be going to scrap yard

It hasn't ran since you rebuilt motor? Yiu need spark, fuel and compression. Which one are you missing? I wouldnt throw any more parts at it. Expensive way to diagnose. Basic datalogger would help also. At least see certain basic functions.

 

[joshuah]

180 compression on all 4 cylinders it ran fine then one day while driving to store it was good I shut off started back up and misfired all the was home . Replaced icm and then it got worse . I replaced every sensor some twice and cranks no start. Replaced ecu same shit Replaced harness same shit

 

[jesse12345]

What harness did you have on the car before? Your car is a 95 with a 97 engine is that right? The 96 harness has a different cam setup than a 97, so I'm just trying to make sure it isn't something obvious now from the harness swap.

 

[joshuah]

Really not sure i know the car VIN comes back as a 95 Talon TSi but the engine is 2g 7 bolt and cam sensor is on the tranny side

I did un loom the plug so it would make it to the cam sensor

 

[Adam]

I had that happen once after I very stupidly washed under the hood without the proper precautions. Took about a week to show symptoms. Trip out was great. Trip home had me puckered. Turned out the cas got wet (green top), but it still had intermittent spark. Eventually the signal was weak enough and the fuel pump stopped running.

Definitely before you buy more parts, do some testing. If you have link that'll help alot. But check the basics. Pull the plugs and make sure that they're ALL firing. Make sure the fuel pumps actually running when the engine is cranking (if you have link you can just turn it on). Check the water temp sensor too. Had those go out before, they give some pretty weird symptoms. Just start at the basics and work your way up.

 

[Car Cannibal]

Ya these cars can get super frustrating. The water temp sensor can ground out and even cause a no start.

Did you make a list of the parts you swapped, can you post them all?

You pulled a plug and confirmed spark?
You confirm fuel pressure and even hear injectors firing?