Gremlins are at work!! NEED HELP!

[BadManGSX]

Ok.. First off I am not a "newbie" when it comes to working on cars, and I can honestly say that I have never had problem I couldn't solve.... Till now I suppose. The reason I am posting here is because I am FAIRLY new to the DSM world and although my recent success with my own 1g build makes me love these cars, my little brothers 2g tsi AWD seems to have taken on a mind of its own. I apologize ahead of time for the length and detail of this post, but I feel that IF or WHEN the problem is solved that it would be a great reference for others with the same issue. First off I will list his mods engine mods since the problem is a starting issue:
1995 talon tsi

-stock 7 bolt
-1g cas
-aeromotive FPR
-Coil on plug setup
-272 cams
-tubular manifold
-fp3065 turbo
-ECMlink
-NGK bpr7es plugs
-New acl main and rod bearings
-New piston rings
-rear battery relocation
-1000cc injectors
-1g cas

So the car was running fine with no issues while running his stage 3 dsmchip. He then purchased ecmlink off of another DSM'er and put it in the car and It would not start. He then put the dsmchip back in and let it idle to get to operating temp and then put the ECMlink back in. The car then started and ran rough. I then came along and helped him get a rough tune so that we could at least drive it down the road and start doing some data logging. At this point the car was idling around 950 RPM and was still a little rich based off of the wideband. We captured a log just sitting in the garage and noticed that the coolant temp sensor was not reading properly and after troubleshooting found that it was a broken wire before the connector and fixed it. Now the car would start cold with the ecmlink. (although I am still puzzled on how well the car ran even without the coolant temp sensor working) We were all smiles until things started going wrong. After we let it idle for 10 minutes the car began to run rough and eventually shut off. Now it would just crank and sputter, but no start. Here is what we troubleshooted:

-made sure the battery had full voltage (check)
-made sure we were getting 12v to power wire for coils (check)
-purchased and installed a new power transistor just in case (check)
-reinstalled the stock crank angle and cam angle sensors (check)
-made sure we were getting and holding fuel pressure (check)
-made sure the injectors were firing with a noid light (check)
-made sure the spark plugs were firing (check)
-compression check across all the cylinders PERFECT (check)
-put in new NGKbpr7es plugs to the right gap (check)
-replaced TPS, MAP, and CTS with new oem ones set the TPS to the correct adjustment (check)
-replaced ecu with a known working one from another car (check)
-replaced 2g mas with a known working one from another car (check)
-checked plug wires for wear and ohm reading (check)

Now at this point it still wouldn't start. So since I knew for sure it was definitely getting fuel, we checked to see if it was getting a strong enough spark. Turns out we weren't getting a strong spark on any of the plugs, but they were firing in the right order. I noticed that he was always having to jump his car if it sat for a while, so having my suspicions with the battery reloaction I had him move it back up front. At the same time we also (just for the heck of it) put in his 650cc injectors and matching dsmchip. With the first hit of the key it fired right up. We then again let it sit and idle. Then it AGAIN started running rough and shut off, to never start again. AGAIN I went through all of the sensors with a meter and they all are checking out fine. The one thing I did notice is that apparently on pin #4 of the harness that connects to the MAS is supposed to be getting 12 volts with the key on. It is not reading anything. My brother told me that it never did read any voltage since he has owned the car so I am not so sure what to think of that. Other than that it has come down to the same issue. We are not running and it seems that again we have a weak spark. I had him put a couple of big ground straps to the block from the chassis to make sure we have a good ground and still nothing. Everywhere I look and every thread I see says the same thing..(power transistor, coil, plug wires, plugs) and considering that all of these are KNOWN good parts it leaves me stumped. We are definitely getting 12v to the coil and it seems to still have a weak spark. Once again I am left with this miscellaneous no start issue. I guess I am asking if anyone has ever had a similar issue or can lead me in the right direction of something I might be totally missing. I could very well be missing something considering all the stress this thing has been causing us both. Any insight would be much appreciated

 

[tenn-gsx]

Probably not going to solve the issue. Just an idea though. Check to make sure that you have disabled the random missfire dtc in link. It will cause an issue similar to what your describing when you use the 1g cas on a 95-96.

 

[BadManGSX]

That is a valid point, although at this point we went back with the stock cas setup.

 

[tenn-gsx]

I would still verify it as not checked. Just to eliminate that as a variable.

 

[bluegs03]

Did you make sure that your connection on the chip, (the one in the ecu) for dsmlink has a good connection and isnt getting messed up?

 

[BadManGSX]

The chip IS getting a good connection.. all pins are perfect on the LINK chip. And we know for sure that at least one ecu works fine with the LINK because we can put it in another car and it runs perfect. As far as the miss fire DTC in LINK, I will make sure the my brother has unchecked this today. It can take another possibility off of the list anyway! I think the main thing that we are having trouble with is a weak spark..... How, I don't know. Also, we followed the wire of pin #4 from the mas to find that it goes to an ecu ground. The book for his car says that he should be getting 12v from there. CONFUSED!! Unless I am supposed to read between the mas and the connector. Then maybe it reads 12v when the ecu gives it a ground??

 

[DSM-sagacious]

Try a new ignition coil. When mine started to go bad it only had weak spark after it got hot. It stumbled when i hit the gas. Worth a try since you can swap it from your other car.

 

[BadManGSX]

The coils have been swapped numerous times. Still no luck.. also the DTC miss fire was removed already. All in all, still a no go.

 

[tenn-gsx]

Try swapping the ecu with your test car.

 

[nightgamer]

try a new coolant temp sensor and then just for giggles unplug your maf

 

[BadManGSX]

Bought new coolant temp sensor. Tried to start and nothing. Unplugged the mas and nothing changed. The ecu we are using is from a running car. I can plug it right in on the other car and start it right up. I swear I can find NOTHING wrong. I have NEVER in my life had problems like this with ANY car!

 

[DSM nOOb]

Have you made sure the signal coming off the cam and crank sensors are within spec?

 

[DSM-sagacious]

If it was running rich or you were cranking alot w/o starting, it could have easily fouled the plugs from fuel. It also occured to me that dsm link is sometimes set to invert the cas sensor. No inversion if your using the stock built-in driver side 95 cas and the opposite for any passenger side cas. You mentioned the firing order was ok but its one of those little details that is easily missed. How about jumped timing? Might check that as well. You could also swap arround some relays for fun. Check for half burnt fuses and such.

 

[steve]

The one thing I did notice is that apparently on pin #4 of the harness that connects to the MAS is supposed to be getting 12 volts with the key on. It is not reading anything.

I think the main thing that we are having trouble with is a weak spark..... How, I don't know. Also, we followed the wire of pin #4 from the mas to find that it goes to an ecu ground. The book for his car says that he should be getting 12v from there. CONFUSED!! Unless I am supposed to read between the mas and the connector. Then maybe it reads 12v when the ecu gives it a ground??

Your misreading something, either looking at the connectors backwards or misreading the diagrams.

Pin 4 (red wire) on the 2G MAF is the MPI/MFI power from the MPI/MFI relay, same one that turns the ECU on and powers the cam and crank sensors, solenoids, ISC, and injectors. So if the ECU is running you should have battery voltage there. Pin 5 (black wire) is the ground for the MAF.

 

[BadManGSX]

As far as the CAS signals.. they are checking out fine. We even have 2 1g CAS's to mess around with as well. In fact originally before all of this happened he was running a 1g CAS. We have been switching back and forth from the two with no differences and both work fine on our other vehicle. I understand the whole fouling plug deal.. that's a no-brainer. I have atleast 6 sets of new NGK's, so we are definitely not on a shortage of plugs Those two subjects are covered well. The inversion for the CAS in the link is not selected at this time due to us using the stock CAS. I went ahead and did go over the timing marks to make sure everything lined up and all is well. I would find it quite hard for it to jump timing considering there is a new tensioner and timing belt, but I went over it nonetheless. To STEVE. It is not so much that I misread anything.. more along the lines of I mistyped it. I got my wire numbers mixed up. Though pin #4 right now is definitely not getting power. So I'm assuming that there is a fusible link that would be in line in the fuse box. I do remember checking all of the fuses and fusible links under the hood a couple weeks ago, but I will have to give them a double check tomorrow.

 

[steve]

It is not so much that I misread anything.. more along the lines of I mistyped it. I got my wire numbers mixed up. Though pin #4 right now is definitely not getting power. So I'm assuming that there is a fusible link that would be in line in the fuse box. I do remember checking all of the fuses and fusible links under the hood a couple weeks ago, but I will have to give them a double check tomorrow.

I'm repeating myself but If your ECU is powering up then you should also be getting power to pin 4 on the MAF since they are both getting their power from the MPI/MFI relay. It the ECU is getting power but the MAF isn't then you have a problem in the harness somewhere. If neither are getting power from the relay then either it's not getting activated or it isn't getting power from the MFI fuse under the hood.

 

[BadManGSX]

Ok. Due to a death in the family I have not been on here for a week or so. I have however figured out the problem and wanted to post it on here to give others an idea that any stupid little thing can have a negative effect on the running of your car. Thanks to everyone that shot me some ideas.. any little bit helps. THE FIX: I started going through the wiring harness to check for broken wires or anything of that nature. I found that my brother had only twisted together, and electrical taped the two coil wires used in swapping to a 1g CAS. I went ahead and soldered them together and shrink tubed them. Then just for giggles, hit the key and it fired right up. Just goes to show you that it is VERY EASY to overlook little things like that and get frustrated when your car won't run. I hope this at least gets people to dig a little deeper when figuring out problems like this. Since we got it running, we went ahead and added a couple of large ground straps from the chassis to the engine block itself. Then moved the battery to the back and have had no reoccurring issues thus far. :SOLVED: