91 TSI no start - help please

[rsofedm]

I've got a 91 TSi that I can't seem to get started.
It's been torn apart to do the headgasket, timing belt, and all related parts.

Fuel:
- replaced fuel pump
- replaced bad ground on fuel pump carrier
- replaced MFI solenoid
- can now smell unburnt fuel
- don't see any leaks

Spark:
- pulled cylinder 1 plug and placed near ground - sparked.
- new and gapped spark plugs

Timing:
- belt was changed and checked, checked, and rechecked before finishing assembly
- crank/cam sensor - made sure it was installed properly
- still need to lookup how to test the CAS but I'd assume if I'm getting spark it's fine.

Air:
- all the vacuum hoses and intake hoses are securely fastened
- throttle pedal seems very stiff - not sure if that's normal on these


One of the other issues it's having (not sure if it's related) is that the low coolant light is on and the fans instantly come on and stay on when the car is put to the "run" position on the ignition switch. Makes me wonder if there's another grounding problem somewhere but I'm not really sure where to start...

 

[400hp93talon]

Make sure you have the plug wires in the right sequence on the coils...If your getting fuel and spark chances are the timing is off some how. Are you positive the cams and crank are timed correctly. Is it popping,backfiring or even trying to start running when you turn it over?

 

[rsofedm]

Myself and one other checked and rechecked the timing belt. I know how important that part is.
as for the plug wires I pulled several diagrams from the intertubes and chiltons and it's correct.

I guess I need to check the other 3 for spark since I guess 2 of the 4 could work but not the other 2 meaning the power transistor, coil pack, or CAS is bad.

It just sits there and cranks as if the MFI fuse were pulled (it isn't).

 

[Benshooter]

Have you compression tested it? I realize you just freshened it up but it's always an integral check for a no start.

Definately check for a strong blue spark on the other cylinders.

 

[Tyeler18]

Check all of the plugs, then make sure you're getting enough fuel. When you installed the fuel pump, did you swap over the o-ring, spacer, and retainer cap off the old one? I was stumped for 2 weeks because the previous owner didn't put the retainer cap on the fuel pump, so I wasn't building enough fuel pressure (I did have fuel though).

Another thing- when you turn the key to "on" does your CEL turn off after 5-6 seconds?

Oh and one more thing, is your CAS in the correct position? You're spark plugs could be firing 180 degrees out if your CAS isn't timed.

 

[eDeclpse92]

i had the same thread posted a little bit ago. I went through and checked everything. How long has it been sitting?? ### that was my problem. bad gas. it went bad in under 2 months. put new gas in and fired right up. a way to test this is the spray brake parts cleaner into the cylinders by removing plugs and cranking it up to see if it fires. also the gas will smell realllllyyy strong and be yellow.

 

[rsofedm]

I'm also going to check the power transistor...

Have you compression tested it? I realize you just freshened it up but it's always an integral check for a no start.

Definately check for a strong blue spark on the other cylinders.

Doesn't the motor have to be warm to do a compression check? can't do that if it won't start?

Check all of the plugs, then make sure you're getting enough fuel. When you installed the fuel pump, did you swap over the o-ring, spacer, and retainer cap off the old one? I was stumped for 2 weeks because the previous owner didn't put the retainer cap on the fuel pump, so I wasn't building enough fuel pressure (I did have fuel though).

Another thing- when you turn the key to "on" does your CEL turn off after 5-6 seconds?

Oh and one more thing, is your CAS in the correct position? You're spark plugs could be firing 180 degrees out if your CAS isn't timed.

- plugs are brand new, gapped, and checked.
- pump was swapped with the 2 plastic pieces and rubber o-ring on top.
- CEL does go off right away if I just leave it in the on position, the coolant level sensor does not go off...
- I triple checked the CAS - it's in the right position.

i had the same thread posted a little bit ago. I went through and checked everything. How long has it been sitting?? ### that was my problem. bad gas. it went bad in under 2 months. put new gas in and fired right up. a way to test this is the spray brake parts cleaner into the cylinders by removing plugs and cranking it up to see if it fires. also the gas will smell realllllyyy strong and be yellow.

I'll try that but I doubt that's it since I would assume that I'd get at least a sputter.

 

[400hp93talon]

Old gas would be an easy fix....cross your fingers haha

 

[eDeclpse92]

not necessarily...old gas can cause a car to not start at all, hard start, or rough running. My car didnt sputter at all on old gas...thats why i thought i had an electrical problem and i got to learn the dsm electrical systm very well... ive read articles on old gas and it can defifntly cause it not to sputter. gas breaks down very fast actually.

also when people were helping me, a bad coolant temp sensor will cause your car not to start or have a hard start. the ohm reading is in the book to
test it.

 

[rsofedm]

not necessarily...old gas can cause a car to not start at all, hard start, or rough running. My car didnt sputter at all on old gas...thats why i thought i had an electrical problem and i got to learn the dsm electrical systm very well... ive read articles on old gas and it can defifntly cause it not to sputter. gas breaks down very fast actually.

also when people were helping me, a bad coolant temp sensor will cause your car not to start or have a hard start. the ohm reading is in the book to
test it.

so did you have to siphon out the old crap or didja just dump a buncha new into it?

 

[eDeclpse92]

i drained the old gas and also dissconnected the return and put a rubber hose into a bottle and let the pump do its thing...i also had a seperate switch for the fuel pump so that made it easier.

 

[doubleclutch99]

also when people were helping me, a bad coolant temp sensor will cause your car not to start or have a hard start. the ohm reading is in the book to
test it.[/QUOTE]
A good way to test that is to turn the ignition to the on position and hold the gas pedal to the floor for thirty seconds. then you can attempt to start it. this tells the ecu to shut down the injectors to avoid flooding the engine . if you have a bad coolant temp sensor, it more or less tells the ecu to dump fuel in the engine. just a thought.

 

[92AWDHX40]

Spark, fuel compression, did you check each cylinder? You never know.

 

[rsofedm]

did a wet compression test since the motor is cold and it came back at 165,165,180,180

also confirmed the CAS is working and in the correct position. It's certainly spraying fuel into the cylinders.

I get spark on all four cylinders but I'm not sure how to tell if it's enough or if it's firing at the correct time. spark on all 4 plugs is more of a white spark than a blue spark - normal?

I haven't been able to test the coolant temp sensor yet, but shouldn't the car work if I just simply unplug it? Typically that'd set it into limp mode, no?

 

[doubleclutch99]

If the coolant temp sensor is bad or not plugged in then the ecu dumps fuel in drowning the plugs makinh it even harder to start. that's why i stated to hold the pedal to the floor for thirty seconds that'll shut the injectors down long enough to start. but that's only if the cts is bad or not plugged in.

 

[rsofedm]

If the coolant temp sensor is bad or not plugged in then the ecu dumps fuel in drowning the plugs makinh it even harder to start. that's why i stated to hold the pedal to the floor for thirty seconds that'll shut the injectors down long enough to start. but that's only if the cts is bad or not plugged in.

I did try that but it only sputtered for a split second and still did the continual cranking.

I was testing the CAS/injectors last night and managed to flood the cylinders so I'll have a look again this morning and see if it's still flooded.

 

[doubleclutch99]

You might need to throw some fresh plugs in it and try it again. especially if you flooded the engine and the plugs are fouled. just a thought .

 

[1 FAST TSI]

If the coolant temp sensor is bad or not plugged in then the ecu dumps fuel in drowning the plugs makinh it even harder to start. that's why i stated to hold the pedal to the floor for thirty seconds that'll shut the injectors down long enough to start. but that's only if the cts is bad or not plugged in.

this is good advice....thats what was wrong with mine..it would crank acrank..then finally spit spudder and start....was a 21 fix from autozone...

if you smell ALOT of gas this is most likely your problem.

 

[rsofedm]

hmmm...

they are brand new plugs. gapped correctly.
it eventually started 1_fast_tsi? mine won't no matter how long it's cranked for...

 

[1 FAST TSI]

hmmm...

they are brand new plugs. gapped correctly.
it eventually started 1_fast_tsi? mine won't no matter how long it's cranked for...

did you hook up a battery charger and crank for like 3mins? honestly i did that before mine started.

 

[rsofedm]

did you hook up a battery charger and crank for like 3mins? honestly i did that before mine started.

holy crap...
anything over 30 seconds risks burning out the starter motor.

 

[92AWDHX40]

Check the coolant temp sensor.

 

[1 FAST TSI]

holy crap...
anything over 30 seconds risks burning out the starter motor.

i have like 4 of em...i had no choice i was 45 miles from home..

 

[rsofedm]

well I tested the temp sensor:

Water temperature of 32°F (0°C): 5.1-6.5 kilo-ohms present
Water temperature of 68°F (20°C): 2.1-2.7 kilo-ohms present
Water temperature of 104°F (40°C): 0.9-1.3 kilo-ohms present
Water temperature of 176°F (80°C): 0.26-0.36 kilo-ohms present

it matched those values verbatim.

 

[rsofedm]

ok, so I've tested the voltage doomabob and the coolant temp sensor. Both seemed within spec. Next I'm going to test the coil pack, CAS, and MAP for proper voltage/resistance/continuity. I'm also going to have a look at the ECU.

One thing I keep forgetting is that there is a compustar remote starter in there. I was told when I bought the car that it didn't work - could that be an issue? I do not know how to go about removing it (I won't use it even if it does work) but if there's a way to eliminate that from the troubleshooting I'd like to hear it.