Author Topic: 1.6 to 8v GTI Conversion, so close, yet so far!  (Read 702 times)

Offline Ed1993

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1.6 to 8v GTI Conversion, so close, yet so far!
« on: 06 June 2018, 20:05 »
Right, so here's my situation, I've recently put a 1.8 8v PB engine into my 1991 Driver replacing the 1.6 EZ engine originally in it, I have read a few threads online where people have been asking about this conversion and the responses usually contained "just buy a gti" or "if you're going to carry out a conversion put a 1.8T lump in it", but for me this project was about learning as I have very little mechanical knowledge i.e. I'd changed brake pads and serviced the car before. But this engine swap involved no real modification, meaning I had less to worry about and could focus on Understanding the 8v engine and digifant system. Anyways the point I'm at now is that the engine is in and has started but is massively over fuelling, so much so that it floods and can't be started. After pulling the spark plugs to find they're covered in fuel and after checking the dipstick there is fuel in there too. Now, here's the good stuff :lol: the wiring was what had caused me an issue in the end and was handed over to other more competent people, and it turned out the ecu wiring loom and rear wiring loom which was replaced to allow for the addition of the external fuel pump weren't just plug and play into my CE2 fuse box as I had thought myself and after going through every wire and referring back to printouts I had provided them of Fusebox wiring locations kindly posted online by rubjohnny they eventually found that there were issues with the power wirimg for fuel pump and ecu so these were wired up with separate Relays above the Fusebox. What this has resulted in is the fuel pump being on constantly with ignition rather than priming and Turning off after 5 seconds as every page I've read online states they should. The guys that are helping me, who are actually professionals unlike myself are suggesting that the external fuel pump is pumping at far too high a pressure. Now I replaced both the In tank lift pump and the external pump myself and know that the lift pump is running at 0.24 bar but the external pump I'm unsure of but was stated as correct for a PB engine from Vwheritage. I've ordered a fuel pressure test gauge and am going to plug that into the fuel rail and see what pressure we've got there. I've read through and downloaded every digifant tuning thread posted online but these are no good yet as I can't get the engine to run. Anyone have any thoughts/similar experiences/professional knowledge they can share? I want to drive my golf again haha, its so close!!
Ed

Offline Ed1993

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Re: 1.6 to 8v GTI Conversion, so close, yet so far!
« Reply #1 on: 06 June 2018, 20:09 »

Offline Ed1993

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Re: 1.6 to 8v GTI Conversion, so close, yet so far!
« Reply #2 on: 06 June 2018, 20:13 »

Offline th3_f15t

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Re: 1.6 to 8v GTI Conversion, so close, yet so far!
« Reply #3 on: 11 June 2018, 10:15 »
Welcome along mate, you sound very similar in your goals to my own GTI 8v project. I hope you figure it out soon.

I can't help much with your issues, but I also have fuelling issues but the opposite from you in that when the engine is running and hot, it starves itself due to fuel evaporation (common problem on the Digifant setup!). My solution is to potentially fit a later setup from a Mk3 Golf GTI 16v or VR6, this uses a single in tank fuel pump setup and after reading your topic wondering if it may be a viable option for you too..?

Anyway, good luck with getting it on the road.

Moving over to Flickr, sorry for the broken picture links!