NO Start issue after Engine swap, HELP!

[Brian in Tucson]

I think you'll find that your old engine with the intermix isn't worth much. Did the old engine start and run before all this? I don't know for a fact that your 02 harness will fit on an 03, it would fit on an 00 or an 01, but that's not too relevant.

I guess I'm saying, if it was a running but bad engine, take the harness off the old engine, use the DME that came with it, and see if it will fit the 03. Looks to me like you did a tactical error--an 00 to 02 would have been easy peasy.

Will the engine crank if you bridge the terminals on the starter? Do you have a good strong ground connection from the starter to the chassis? Are all the grounds in the trunk firmly attached to the chassis?

[The Radium King]

03 has a different cam adjuster. you might ba able to repurpose the harness in some manner, but you need the 7.8 dme.

[Geof3]

Wow, why not just source a full ecm, immobilizer, key combo for the engine and trans in your car? Seems like a lot of noodling to little result. Also, why did you need a 2.7 harness for a 3.2 engine? It doesn’t matter what type of car the engine came out of, it just wants gas, spark and air. It is your harness and control systems that need to mate to the engine to give it all of that. Seems like you have a whacky Frankenstein thing going on with your swap...

[Brian in Tucson]

Originally Posted by The Radium King

03 has a different cam adjuster. you might ba able to repurpose the harness in some manner, but you need the 7.8 dme.

You sure know a lot of stuff!

[78F350]

Originally Posted by Brian in Tucson

You sure know a lot of stuff!

TRK's point about the "Connector I" was great info. I hadn't even thought about that part of it until he mentioned it. That plug comes from the chassis harness and the DME 7.2 harness will not power the 7.8 until those pins are corrected.

[Qmulus]

You are on the right path with the wiring. Get the body harness to engine harness wiring correct, then get the OBD communication working. You will then need to get the DME matched to the immobilizer before you can even attempt to start the car. For this, you will either need to take it to a dealer, or find someone with a PST-2 or PIWIS II, etc., and get the programming codes from your car from the dealer. Then the DME and immobilizer can be properly matched. I would NOT recommend getting the immobilizer, DME and key from another car even though it would work, as this can/will lead to other problems down the road as your car would now be electronically whatever car you got the parts (by VIN) as far is Porsche is concerned. That means the programming codes, etc., for your car would no longer be valid. If you would need a key or DME programmed down the road, you would have to have the VIN from the car you got the DME and immobilizer from to get the programming codes to allow the process to work. If you don't have that, it can get complicated and expensive.

Sooo, what did you do about the fuel system? The '03 uses a single line, non-returning fuel system with the regulator on the pump, whereas the '02 uses a returning system with the regulator on the fuel rail. On the one car that I know that was converted from ME 7.2 to 7.8, the fuel system also had to be converted to get to operate properly. There may also be some communication issues with the ABS system and cluster as the ME 7.8 uses more CAN integration than the ME 7.2 cars did. That may not be evident until you get it running. I believe that the '03 also uses different oxygen sensors than the early cars. Did you also get these?

[xr_guys]

Hi Guys,

I got the a tool from our local autoparts


I used the small flat tool, the next size was to big. Just insert and push till feel the little snap.

Got Terminal 30 moved from pin #7 to pin #2 of connector 1.

How about the (Throttle VLV MTR +) and (Throttle VLV MTR -), on 7.8 this is located on #7 and #9, currently this two slots are vacant.

King & Qumulus, thank you for your continuous help, i'm new to Porsche

XR

[The Radium King]

they are located on other connectors on the earlier harness. pm me your email address and i can send to you.

[xr_guys]

King,

Private email sent.

XR

[xr_guys]

Qmulus

The fuel line is a single port on the 2002 Boxster S, similarly the 2003 is same. I have no extra fuel return line on the engine. I did not saw a pressure regulator on the 2003 engine itself. I also manually powered up the fuel pump bypassing the relay, the fuel have good pressure. If I missed a fuel return line on either car or engine side I should have fuel leaks? I was surprise no fuel smell of leak detected.

Then again, I’m still learning the Porsche system, my confidence is questionable honestly? I’m winging it as I go, but not reckless.

I think this conversion is more challenging due to the 02 & 03 year of cut off when they started switch between DME 7.2 to 7.8.

Thanks,
XR