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Engine cranking no start. 2002 VW golf GTI with Ko4 turbo and 750cc injectors.

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So recently I have been wanting to tune my car myself so I got some 750cc grams performance injectors and a bigger intercooler for the ko4 turbo. I decided to go with the emu black ECM because they offer a PNP for my wiring harness and it has a base map for my engine already on it (1.8T AWP engine code). When I first put in the ECM I also put in the bigger injector so I could start tuning it. I went threw the basics and started the engine and at that point, I noticed that I was not getting a reading from the map sensor. so I thought it could be the software now working right so I deleted the base map like an idiot and the software as well. I then redownloaded the software and the base map(which is supposed to be the same as what was already on it) then went to check the map sensor and saw that I still was not getting a proper reading. I decided to see if it would still start and it did not start. at this point, I decided to get in contact with ECU masters to see what why i was not getting a reading from the map sensor. I was then informed to put the stock injectors back in and try to start it and send them the logs so they can see what is going on. After I did all of that they then told me that the ECU thought that the built-in map sensor was the one that came with the ECU when I bought it not the one that was already on the car from OE. I was then told how to wire it in and was given the information to calibrate it. After I wired in the map senor and calibrated it, I was finally getting a proper reading of 78 Kpa (at 7,000 Ft). after that I went to start the engine and it still did not start. then I went threw the ignition system and confirmed I was getting spark from all 4 coils( going to check the ignition timing in the morning). after that, I went to the fuel pump and I can hear it priming so I went to the fuel rail which is getting pressure. at this point, I was recommended to try starter fluid to further help determine if it was an ignition issue or a fuel issue. on the third try of putting some starter fluid in the intake manifold, I got a little spurt of the RPM jumping to 335 then dropping back to 200 RPM (it's low bc the battery is dying). that was about 2 hr ago. at that point, I decided maybe I had some faulty injectors so I switch back to the stock ones(380cc) and reloaded the stock map for the stock injectors. the engine still did not start. at this point, I am at a loss for what the issue could be.

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Hi Corey, I've had a quick look through your map and log and there's nothing immediately that jumps out at me. I note that the injector setting is currently set to 360 cc - I assume you've been changing that to suit the larger injectors? Have you checked with a timing light to ensure the base timing is correct? If you can get the engine to fire with engine start then this would suggest you're supplying insufficient fuel. A couple of quick and dirty tests you can complete:

1. Simply double the numbers in the VE table in the cranking and idle region and see if that makes a difference - Make big changes initially and just try to get the engine started. You can worry about fine tuning later.

2. Find an LED test light and ensure the ECU is physically triggering the injectors (put the test light across the two terminals of an unplugged injector plug on the harness side) and crank the engine. The LED should flash if the injector is being triggered.

Not sure if it applies here, but there are two steps that are often missed.

The first is checking the ECU TDC and actual TDC of the engine are the same. There should be a set proceedure for this, usually locking the timing at 0 degrees and cranking it with the plugs out (and a fully charged battery) while someone checks with a timing light. You may need to adjust the base timing a little to get them to co-incide.

Relative to this is checking the #1 is firing on the compression stroke, and not the exhaust stroke - but this is often indicated by the exhaust igniting.

After further troubleshooting, I found out that the injectors are triggering when cranking the engine and it is getting spark. so I decided it might be the ECU because it ran with the stock ECU then I put in the new ECU it started then I deleted the base map and reinstalled the base map and it did not start after that. so I put the stock ECU back in and it still won't start so it's not the ECU it's something else with the engine with either the wiring or a sensor.

Do you have fuel pressure? Make sure the battery is charged. I nearly always have a charger attached while working with a car when the engine isn't running.

When you put the stock ECU back, did you also put the original injectors back in?

I did have the battery charged back up. the stock injectors are back on the fuel rail. I know there is pressure in the line I don't know how much exactly.

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