Hello,

issue here took care to the mall then gym. Got back it and it wouldn't start. It sounds like it wants to turn over but doesn't quite make it. Starter? Alternator?

Very similar to this vid below.

Also my dash lights like srs, check engine and windows won't light up or roll down now.

Alright, so following this thread I got all the way to testing my coolant temperature sensor. When I go to test the voltage and resistance it doesn't give readout of any kind. The multimeter works just fine, touched the positive and negative to my battery and it gave proper voltage readout. Does this mean the coolant temperature sensor is completely broken, or is it something else?

Got a new motor and its not firing on 1 and 4..... heres a video on whats going on idk if its a cas sensor or what...

cant post video... will post tonight..

I've tried everything on the "how to diagnose a no-start" thread now, and I'm still not having any luck. Just replaced my coolant temp sensor with a brand new one; still no start.

Now my car went from starting just fine one day to this the next day, after sitting in my driveway during a very cold winter storm. I figured it just won't start cause it's freezing, but here it is 70F out and still not starting. When I first crank it, it sounds like it's about to start. Here is video I took of it.


I'd appreciate any help at all, thanks.

Are you sure its not firing on 2 cylinders?
The reason I am asking is because your firing order could be wrong. 95-96 ecu had 4-1-2-3 and 97-99 had 2-3-4-1.
Might be worth looking into.

I have tried both firing orders... :/ imam pull spark plugs today and fuel test and air test.... Then imam pull out the trusty multimeter and start checking sensors thnks to the lovely no start thread diagnosis thread I have come across.. any ideas and all ideas welcome though thanks for the insight on the firing order though

Yesterday I went to start my car, all it did was crank, wouldn't start. Looked in my passenger foot area where my ECU is hanging out, and its about in 2 inches of water Drained the water (it was only on that passenger side), burnt myself a new EEPROM chip, and swapped in a known good ECU. Same thing. Cranks but won't start. There is no check engine light. I have performed the following diagnostic steps:

Check voltage at fuel pump. Reads around 9 volts when cranking.
Check output from MAFT "temperature" (grey wire), reads 3.9V as it should.
Unhook fuel rail to see if fuel comes out during cranking. It does.
Take out spark plugs to check for flooding. Doesn't appear flooded, doesn't smell like gas, spark plugs are not wet.
Remove and check MPI control relay. The relay switches and performs as designed.
Check MPI fuse. Not blown.
Check fuel injector resistor box. All read approximately 6 ohms.
Pull fuel injector electrical connector, turn key to "on" position. Reads 0V. I am under the impression this should read 12V.
*edit* that last one is incorrect. Both wires are reading +12v with key in "on" position. I originally measured voltage across the two wires instead of using a chassis ground, which would of course read 0 volts differential between the two.

Interestingly enough, after drying my water ridden ECU out and trying it, I see the same problem of 0V at injectors. Where do I go from here?

Possibly relevant mods:
MAF translator + GM MAF
Wideband in place of stock O2, wired to ECU
FIC 1050 cc injectors
Chipped ECU, tuned by me. Tune has been working fine for months.

Check all fuses first and try testing with a chassis ground or battery power to see which is not working on the injectors and if its the ground check the coolant temp sensor.

j_wolfe said:

Pull fuel injector electrical connector, turn key to "on" position. Reads 0V. I am under the impression this should read 12V.

Click to expand...

You shouldnt have constant 12V at the injectors, otherwise they would never stop spraying. In no start conditions i always begin with narrowing it down to fuel or ignition. Fuel is easiest for me by spraying starting fluid while cranking, if it fires up you have fuel related issues, if still not start then start focusing on ignition related issues

inthemidst said:

Check all fuses first and try testing with a chassis ground or battery power to see which is not working on the injectors and if its the ground check the coolant temp sensor.

Click to expand...

Put the ground connector for the multimeter to chassis ground, measured both ends of the injector connector, 12.3 volts on one, 11.8 on the other. That's not how that's supposed to work, is it? Same results with both ECUs. Coolant temp sensor resistance is correct for the temperature.

Spades said:

You shouldnt have constant 12V at the injectors, otherwise they would never stop spraying.

Click to expand...

Are you sure? I don't think that's right. Injectors work by receiving pulses. I looked it up to be sure. This thread states they have constant voltage applied, and a pulse applies a lower voltage to trigger the injector.

http://www.dsmtuners.com/threads/help-low-voltage-at-injectors.439116/

I was trying to measure voltage across before, so that was wrong. I have close to twelve volts on both connectors, which seems to be correct. I definitely have spark, as I checked when pulling my spark plugs. Would starting fluid make it down through all my intercooler piping? I don't have any handy. It's a huge PITA to get directly to the throttle body because of my piping configuration. I think I'm gonna try a noid light and see what happens.

There is a constant 12 volts with key on run and the ground pulses comes from ecu do the test like I mentioned earlier to figure out if its the ground/ecu or power/ignition.

From what it saying u don't have ground pulses but did u test the ground while cranking if u did I would start checking the cam n crank sensor.

So you made sure the ecu connector terminals were all clean before installing the ecu.

maybe your not getting enough pressure from the fuel pump did you check that yet.

If you don't have starter fluid, you can fill a small can with regular gasoline and pour a small amount into the throttle body [not too much] and see if the car catches or stutters as it turns over.

inthemidst said:

From what it saying u don't have ground pulses but did u test the ground while cranking if u did I would start checking the cam n crank sensor.

Click to expand...

Right. I have +12v coming in on both wires to the injector with the key turned "on". By attaching a 12v light bulb to both ends of the connector plug, I can see that there are no pulses coming in while cranking. Is this what you mean by testing the ground while cranking?

I did inspect the connector terminals on both the ECU and wiring harness side. This part of the ecu wasn't submerged, only the bottom part where the EEPROM chip is located. I'll get some starting fluid, as I have no gas besides what's in my tank and I don't feel like getting a mouthful of that at the moment

Well if u don't have any ground pulses and u submerged part of the ecu in water most likely the ecu is toast.

j_wolfe said:

Would starting fluid make it down through all my intercooler piping? I don't have any handy. It's a huge PITA to get directly to the throttle body because of my piping configuration.

Click to expand...

You can remove the BOV line at the intake manifold and spray through there, you dont need it to run and idle, you just want to see if it will fire up for a second

Spades said:

You can remove the BOV line at the intake manifold and spray through there, you dont need it to run and idle, you just want to see if it will fire up for a second

Click to expand...

Wow, why didn't I think of that?

Thanks everyone for all your suggestions. I got the car to start. I took both my ECUs and tested them on my buddy's car. Amazingly, the "water damaged" one works, the "known good" spare I had didn't. Yes, I'm sure I didn't mix them up. I'm not surprised the ECU survived since it has that thick coating on the outside of it covering all electrical connections (except where the socket is). No idea why the car wouldn't start earlier with the ECU. Maybe the car still had water somewhere that hadn't dried out yet?

So im having the same problem as cobolt anyone have this issue and find solution..?

It's been quite a while but I'm back at it and trying to get my 1G TSi up and running again.

After replacing the head gasket I can't get it to fire, it will crank just fine but won't fire.

I've checked all the basics. Plug wires are in the correct order, I have spark, I have compression, I have fuel (I don't have fuel from the pump as it's not running for some reason so I am spraying some starting fluid in the intake in hopes of just being able to get it to fire), the CAS is installed correctly

The battery is shot so I'm using another vehicle with jumper cables attached to it so it will crank. It's cranking kind of slow but I'm pretty sure it's fast enough to get it to fire.

The spark plugs are new and gapped correctly so I don't think that's my issue.

I had my ECU professionally re done a few years ago because the caps were leaking so I don't think it's the ECU (The boost gauge goes to 0 and the check engine light turns off like they are supposed to) Although I haven't had a chance to pull it out and look yet.

I'm not getting a check engine light.

Any advice is greatly appreciated as I'm pretty stumped right now.

Thanks!

If your sure your fuel pump does work maybe injectors are not opening because of the coolant temp sensor is probably bad or its not connected properly.

I would get your fuel pump fixed first but it should sputter a little bit on starting fluid. Make sure that the spark is blue not orange and week. Also low voltage will make week spark since u said it is cranking slow. Ive seen this before in my friends 1g and he didn't have the motor grounded so make sure all your ground wires are clean and tight. Good Luck