urs4 big turbo starting issues....

[euro_urs4]

ok guys stating a new thread to keep you up to date what has been done and see if you can help me narrow down what the problem is, car has built bottom end pistons rods etc, top end also built valves etc, i am running a holset super40 turbo, vems ecu, 1000cc injectors, 044 fuel pump, (just a few necessities you might need to know about ), and my problem now is that the car just keeps cranking and cranking over, and wont start, (when cranking over it doesnt even seem like it wants to catch to start just as if you were to pull the fuse for the fuel pump and crank it just turns and turns)....

So ive checked already it is getting fuel to the injectors and out the fuel rain, injectors are getting a pulse signal, there is spark, the camsaft sensor is intact, the flywheel pin is still intact, and the motor is timed correctly. (IMO i think it has something to do with timing however could be anything),

now i need your guys help cause the forums brains put together will help me solve this where myself im kinda stumped right now, but give me some input on what to look for next or what to check and i will narrow things down until we start it. (if you need some more info on the car let me know)

[Billman]

did you used adjustable timing pulley on the cams?

See that:

1. Timing pin on the flywheel coincides with the hall window on the camshaft pulley
2. The distance between the Crankshaft sensor in in the right distance from the flywheel pin.
3. Share with us your VEMS config. Maybe is on your settings there something odd

[UrS4boy]

This is the first time you mentioned VEMS. That is likely your problem right there. I would have started the car on Motronic before switching to VEMS so at least you would know that everything is lined up/timed properly and functioning before you moved over to VEMS.

[Billman]

It would work if we could check it out.

[WabTheKing]

are your fuel lines the right way round? sounds silly but ive seen it done loads of times

[killa]

how much compression do you have?
is the setup firing at the right time (do you have the correct firing order?

[UrS4boy]

Did you swap the two pins on the VEMS harness to the RPM sensor or buy the adapter harness? From the EFIExpress website:

"only two pins need to be reversed on the factory harness leading to the RPM input on the transmission bell housing. For customers desiring a fully plug and play system an adapter harness can be purchased which accomplishes the pin swap."

Without the RPM signal, I doubt that your engine will start. Could be your issue.

http://www.efiexpress.com/catalog/product_info.php?cPath=1&products_id=1

[euro_urs4]

did you used adjustable timing pulley on the cams?

See that:

1. Timing pin on the flywheel coincides with the hall window on the camshaft pulley
2. The distance between the Crankshaft sensor in in the right distance from the flywheel pin.
3. Share with us your VEMS config. Maybe is on your settings there something odd

i will have to check that the timing pin on the flywheel coincides with the camshaft pulley still (just figured that if the flywheel goes on in only one way then that would be ok ) and what do you mean the distance between the cranshaft sensor is in the right distance from the flywheel pin? and i will get my vems config for you guys to take a look at it

This is the first time you mentioned VEMS. That is likely your problem right there. I would have started the car on Motronic before switching to VEMS so at least you would know that everything is lined up/timed properly and functioning before you moved over to VEMS.

yes very true should have done that, but didnt think of it at the time, however i did swap my friends stock ecu and injectors, but the fuel pump wouldnt turn on wit his ecu so i couldnt test it that way.

are your fuel lines the right way round? sounds silly but ive seen it done loads of times

im almost positive the fuel lines are on the right way, however doesnt hurt to double check i will have to look at that

how much compression do you have?
is the setup firing at the right time (do you have the correct firing order?

i dont recall the exact number however it was 150 or so, and is there any way to check the setup of the firing order to make sure its correct, seems correct to me but would check it to make sure

Did you swap the two pins on the VEMS harness to the RPM sensor or buy the adapter harness? From the EFIExpress website:

"only two pins need to be reversed on the factory harness leading to the RPM input on the transmission bell housing. For customers desiring a fully plug and play system an adapter harness can be purchased which accomplishes the pin swap."

Without the RPM signal, I doubt that your engine will start. Could be your issue.

http://www.efiexpress.com/catalog/pr...&products_id=1

and yes the pins have been swapped with the adapter, reads rpm when cranking over,

I talked with Marc Swanson since i bought the ecu from him, and we might be thinking that it is a tuning issue with fuel possibly, since the plugs dont even get wet after cranking it over a few times, however there is fuel coming out of the end of the fuel rail if i crack it open, my guess is that the injectors are getting fuel however arent letting fuel into the motor, will have to look into that

[UrS4boy]

If this was a Motronic car, I would suggest that the ECU is not getting all three of the G40 cam sensor, G4 Crank position sensor and G28 engine speed sensor signals at the same time. Without all three, a Motronic ECU does not have enough information to open up the injectors at the right moment and for the correct period of time and THEN fire the coil and spark plug(s). Having the fuel rail pressurized does not mean that much in this case. All it means is the G28 engine speed sensor is probably fine (because the ECU has fired the J17 FP relay).

From a previous post (on quattroworld):

"The G28 engine speed sensor is the trigger for firing the J17 fuel pump relay which also opens power up to a number of devices. The G4 crank sensor and the G40 Cam Position Sensor are needed by the ECU to determine exactly where the engine TDC is. This is because on any four stroke engine, the crankshaft turns twice as fast as the camshaft - so with G4 alone on the cranks at 62 deg btdc it's impossible to know if the engine is on the compression or exhaust stroke. The purpose of G40 is to identify the camshaft position and therefore determine the phase of the engine so that ecu has all the info it needs to start initiating coil and injector activation. (Reference Paul N. at S2central.net) After the engine is running, the ECU can run on G4 alone if the G40 fails - however, the ECU will retard the timing signifiantly if the G40 fails while running. While the fuel pump relay is still energized with a failed G40, the ECU will not fire the ignition or the injectors because it needs both the G40 and the G4 crank sensor signals to do so."

I suspect you have a G4 or G40 problem.

http://forums.quattroworld.com/s4s6/msgs/20986.phtml

Dave F.

[euro_urs4]

If this was a Motronic car, I would suggest that the ECU is not getting all three of the G40 cam sensor, G4 Crank position sensor and G28 engine speed sensor signals at the same time. Without all three, a Motronic ECU does not have enough information to open up the injectors at the right moment and for the correct period of time and THEN fire the coil and spark plug(s). Having the fuel rail pressurized does not mean that much in this case. All it means is the G28 engine speed sensor is probably fine (because the ECU has fired the J17 FP relay).

From a previous post (on quattroworld):

"The G28 engine speed sensor is the trigger for firing the J17 fuel pump relay which also opens power up to a number of devices. The G4 crank sensor and the G40 Cam Position Sensor are needed by the ECU to determine exactly where the engine TDC is. This is because on any four stroke engine, the crankshaft turns twice as fast as the camshaft - so with G4 alone on the cranks at 62 deg btdc it's impossible to know if the engine is on the compression or exhaust stroke. The purpose of G40 is to identify the camshaft position and therefore determine the phase of the engine so that ecu has all the info it needs to start initiating coil and injector activation. (Reference Paul N. at S2central.net) After the engine is running, the ECU can run on G4 alone if the G40 fails - however, the ECU will retard the timing signifiantly if the G40 fails while running. While the fuel pump relay is still energized with a failed G40, the ECU will not fire the ignition or the injectors because it needs both the G40 and the G4 crank sensor signals to do so."

I suspect you have a G4 or G40 problem.

http://forums.quattroworld.com/s4s6/msgs/20986.phtml

Dave F.

the g28 sensor seems fine since it is reading rpm, and the g40 i checked and is in place and intact, and the g4 i will have to swap out from my friends running s4 and see if thats the problem since there isnt really any way to visually see if it is working or not correct?

[UrS4boy]

the g28 sensor seems fine since it is reading rpm, and the g40 i checked and is in place and intact, and the g4 i will have to swap out from my friends running s4 and see if thats the problem since there isnt really any way to visually see if it is working or not correct?

You must not have read all of the info in the link I provided. For example, this:

"Testing a G4 is something like this: "Test the resistance between between pins 1 and 2 of the black connector end of the G4. (With the bump on the middle of connector up, the pins are, left to right, 1 ,2 and 3.) Between 1 and 2 you should have "approximately 1000 ohms". If NO = replace, If YES - test between pins 1 and 3 and then 2 and 3. Both should be infinite ohms, i.e. "open", If NO = replace. "

If the G4 is fubar'd the engine will not start. If the engine is running when the G4 fails, it will keep running, but never start again (until you replace the G4).

I don't accept your visual check on the G40 as assurance that it is fine. You need to check if it is working electrically. Marc S. at EFIExpress sells an LED tester or you can search here for a Paul N. post on how to insert an LED inline to check for the pulsed G40 signal.

[Jamo]

Wheres your vems map? If your injector order is wrong then it won't fire and will just crank

[prj]

If that stock ECU was good and working on another car and it was not activating injectors/pump when you turn the thing over, you should have checked fault codes.

From what you wrote I don't really understand if that ECU was bad or not.
I would try with a known working ECU from another car. It must start on that ECU - if it does not, your problem is not VEMS or Motronic.

[euro_urs4]

You must not have read all of the info in the link I provided. For example, this:

"Testing a G4 is something like this: "Test the resistance between between pins 1 and 2 of the black connector end of the G4. (With the bump on the middle of connector up, the pins are, left to right, 1 ,2 and 3.) Between 1 and 2 you should have "approximately 1000 ohms". If NO = replace, If YES - test between pins 1 and 3 and then 2 and 3. Both should be infinite ohms, i.e. "open", If NO = replace. "

If the G4 is fubar'd the engine will not start. If the engine is running when the G4 fails, it will keep running, but never start again (until you replace the G4).

I don't accept your visual check on the G40 as assurance that it is fine. You need to check if it is working electrically. Marc S. at EFIExpress sells an LED tester or you can search here for a Paul N. post on how to insert an LED inline to check for the pulsed G40 signal.

ahh i didnt get to that part thank you, i will go ahead and test it that way to make sure its in good working order and same goes for the g40 signal i will test that with the led after i read the write up,

Wheres your vems map? If your injector order is wrong then it won't fire and will just crank

kinda new still with vems how do i get the map for you guys? (i will get that later after work once you guys guide me how to upload one for you)

If that stock ECU was good and working on another car and it was not activating injectors/pump when you turn the thing over, you should have checked fault codes.

From what you wrote I don't really understand if that ECU was bad or not.
I would try with a known working ECU from another car. It must start on that ECU - if it does not, your problem is not VEMS or Motronic.

the stock ecu is in my buddies running car, (when i installed the vems unit i had to swap over a wire and add an adapting wire and so forth to match up with the ecu from efi express, could that cause the stock ecu not to turn on the fuel pump?)

[Billman]

simply save config and send us the file