1G TSI - Cranks but wont start ?

[MissionSk8r21]

I'm trying to diagnose a problem on a buddies car

Its a 1990 Talon TSI 5-speed, everything stock except for a blow off valve and a manual boost controller. It was a $500.00 daily driver beater he picked up. Most of the car has about 200k+ miles on it, but the motor is relatively new and has great compression.


The car will crank, and crank, and crank.................and crank but no matter what I cant get it to fire up. No check engine light, no unusual noises, and nothing was changed to cause this issue.

He went to start it the other day and it started really ruff and was bad driving in lower rpms, but drove fine above about 3k. Now its in his driveway and we cant get it to start at all, just keeps cranking.


Ive tried changing the plugs and wires.

Ive charged and tried jumping the battery.

I disconnected the hose from fuel filter to fuel rail and the car does dump fuel while its being cranked.

It has new gas.

The timing seems to be ok. Both cam gears line up the same TDC.


Im not sure where to go from here. You would think a bad ECU or sensor would cause a check engine.



Just looking for some suggestions on what other possibilities could cause this.

 

[1gDSM4g63]

Make sure the everything is grounded and check the relays.

 

[stefanOst]

I had a problem a while ago where it would take a ton of cranking to get it started, and would run pretty badly until it warmed up. Turned out to be a coolant temperature sensor. It would be really hard to start it on cold starts, but would start easy once warmed up. Car would throw a CEL about 2 or 3 minutes after the car started, so maybe check for codes anyways.

Just something else to look at

 

[ShawnsGarage]

\

The car will crank, and crank, and crank.................and crank but no matter what I cant get it to fire up. No check engine light, no unusual noises, and nothing was changed to cause this issue..

When you say no Check engine light is the light coming on for 5 sec when you turn the key to the ON position?

 

[mentalTSiAWD]

Do you have fire to the plugs when you are cranking it? If not, I would suspect a coil malfunction.

 

[1GDSMGSX]

Seonds to that, do you have spark at the plug? I just lost my Ignition Control Module, car cranked and cranked, had fuel, no spark, checked all the fuses, ICM is the power unit.

 

[ROOKIE1]

Check spark plug wires (firing order)
Boost leak test
Do not always get a CEL with ECU going bad .
Unplug your MAF , try starting . Could be bad .

 

[->PrOjEcTGS<-]

Well, to start you need to know what it takes to get the car to start. Air, Fuel, and Spark.
Air:
1. Compression Test. No compression = no fire. (slipped/broken timing belt)

Fuel:
1. Is there gas in the tank? No gas = no fire (Leak in tank/no money)
2. Fuel Pressure test (bad fuel pump/fuel pressure regulator)
3. Injectors firing? (CAS's are known to fail and cause the injection and ignition systems to fail.)
4. Clogged fuel filter? (poor maintenance) 200k filter? Eeek!
5. MPI relay/fuse (Injectors and pump won't work with out this)
6. Injector Resistor Pack (injectors won't fire without one)

Spark:
1. Spark plugs good? no spark = no fire (fouled spark plugs don't fire well)
2. Wires good/connected properly? (Wires deteriorate over time and lose their ability to do their job.)
3. Coil good? (Can't have spark without power to the spark plugs)
4. Power transistor good? (Can't power the coil without a good one)
5. CAS good? (won't fire the injectors, spark plugs, or turn the fuel pump on if this is bad)

Generally after you solve the fuel, spark, and air problems your car will start but not run very well here are some things to check to get it running good again.

Coolant Temp Sensor
Mass Airflow Sensor
TPS sensor
O2 Sensor
Idle Speed Controller

After all the sensors check out I would suspect your ECU. The ECU processes all the sensor's input and tells the fuel and spark systems what to do and when to do it. All the procedures to check the sensors can be found in your haynes manual or FSM.

Hope this helps

 

[MissionSk8r21]

Well, to start you need to know what it takes to get the car to start. Air, Fuel, and Spark.
Air:
1. Compression Test. No compression = no fire. (slipped/broken timing belt)

Fuel:
1. Is there gas in the tank? No gas = no fire (Leak in tank/no money)
2. Fuel Pressure test (bad fuel pump/fuel pressure regulator)
3. Injectors firing? (CAS's are known to fail and cause the injection and ignition systems to fail.)
4. Clogged fuel filter? (poor maintenance) 200k filter? Eeek!
5. MPI relay/fuse (Injectors and pump won't work with out this)
6. Injector Resistor Pack (injectors won't fire without one)

Spark:
1. Spark plugs good? no spark = no fire (fouled spark plugs don't fire well)
2. Wires good/connected properly? (Wires deteriorate over time and lose their ability to do their job.)
3. Coil good? (Can't have spark without power to the spark plugs)
4. Power transistor good? (Can't power the coil without a good one)
5. CAS good? (won't fire the injectors, spark plugs, or turn the fuel pump on if this is bad)

Generally after you solve the fuel, spark, and air problems your car will start but not run very well here are some things to check to get it running good again.

Coolant Temp Sensor
Mass Airflow Sensor
TPS sensor
O2 Sensor
Idle Speed Controller

After all the sensors check out I would suspect your ECU. The ECU processes all the sensor's input and tells the fuel and spark systems what to do and when to do it. All the procedures to check the sensors can be found in your haynes manual or FSM.

Hope this helps

very, very helpful. I will check it all and get back to you on what works.