Engine Swap and engine wont start

[alstarz88]

Hi

Let me explain where i am at i have just put a 3.2 S 2002 engine in my boxster which has also has a full wiring loom from a different car i also have changed the ECU (2000) Alarm and transponder from a 3rd location now i am experiencing issues starting.

i have lights on the dash but it is acting like the immobiliser isn't releasing.

I have done some diagnostic and this is what i have come accross from the dme relay the red/blue cable puts out an incredibly low voltage

also the red brown cable from the relay seems to terminate at the white multiplug (i believe this cable is supposed to go to the dme but not sure and do not see why there should be a discrepancy between the 2 looms seeing as the both were 2002

the other option is that the dme and alarm either arent communicating or the transponder is incorrect

thanks for any help you can offer

Regards

Ross

[alstarz88]

Forgot to mention

original car

2.5 boxster manual 98

uprated to

3.2S Boxster manual 2002

[Guest]

it's the ecu 2000 or 2002?

2000 is dme 7.2

2002 is dme 7.8

the 2002 engine needs the dme 7.8 and is a can bus system.

regardless - your 98 boxster does not have a can bus. It's not plug and play. You need rewiring.

Sorry for the bad news.

Sergiu

Edited September 30, 2009 by sergiu

[alstarz88]

it's the ecu 2000 or 2002?

2000 is dme 7.2

2002 is dme 7.8

the 2002 engine needs the dme 7.8 and is a can bus system.

regardless - your 98 boxster does not have a can bus. It's not plug and play. You need rewiring.

Sorry for the bad news.

Sergiu

it is re wired the car has full 2002 wiring loom, cluster, abs, HVAC etc the ecu is from a 2000 car same part number as 2002

hope that clears it up a bit

[Guest]

I'm glad you got the rewiring done. That is the hard part. The issue that I still see it's that I do have a 2000 car and the dme was 7.2. The dme changed in 2001 to cover the new cluster with can bus ; I guess the pins might be different. between your harness and the noncanbus 2000 dme. Might be enough just to reprogram with 2002 software - ask the dealer.

When I first tried to start my car with new dme the start enable wire from the neutral sensor was not in the right position. I was blaming the immobilizer too.

Edited October 1, 2009 by sergiu

[alstarz88]

Hi

had a chance today to do some playing and with the aid of a wiring diagram for cu me 7.2 vehicle side have discovered that quite a few wires are missing which leads me to the conclusion that even though i thought the engine was a 2002 and wiring loom is 2002 they can not be from the same year and maybe the engine is not a boxster one.

here are the wires i investigated

b12 on dme og/rd not present

b20 on dme ye/rd not present

b23 on dme rd/bn not present

b18 on dme wh/gn not present

these all come from the white multiplug and on the car loom are there just not there in the engine loom. would the wiring loom colours changed from 2001 (this is the diagrams i have and seem to match colours of vehicle loom so far) on or does the 996 engines have different colours.

thank you guys for your help so far

[alstarz88]

I also discovered that the ignition coil wires are in the wrong order the engine is defernitley out of a bxster as th exhaust manifolds are the right way round and i didn't have to change anything to get it to fit like other people who have put in 3.4+ engines so i can only summise that this engine is 7.8 dme does anyone have the wiring diagrams for this dme so i can compare

Regards

Ross

[txhokie4life]

I also discovered that the ignition coil wires are in the wrong order the engine is defernitley out of a bxster as th exhaust manifolds are the right way round and i didn't have to change anything to get it to fit like other people who have put in 3.4+ engines so i can only summise that this engine is 7.8 dme does anyone have the wiring diagrams for this dme so i can compare

Regards

Ross

I believe (tho I have not checked myself -- always forget to do so) there is an engine number stamped on the bottom of the engine.

This can be decoded to determine exactly what type and year the engine really is.

Now if someone has swapped out parts -- who knows -- I do not know if the coil paks are somehow particular to a certain

DME version -- but if they are -- you can check them by finding a part number on them and figuring out

what engine/DME they should be with.

It is really easy to grab the wrong coil paks -- at least between a 2.5L and a 3.6L -- they are physically interchangeable,

although different part numbers -- I caught myself -- so I don't know if incorrectly installed would

mimic you failure mode.

thanks,

m

[RFM]

Coils are engine MY related not DME. The main difference is the coil pipe design, old type till MY 02 (engines with PLASTIC spark plug tubes), new type from MY 03 (engines with STEEL spark plug tubes). It's possible to separate the coil body from the pipe and change them.

[Guest]

colors are the same 99% 996 and 986 even year to year. Buy the Bentleys and a Durametric. Also Bentley has some mistakes in the pinouts but it gives you something to start out with.

Good Luck,

Sergiu

[alstarz88]

colors are the same 99% 996 and 986 even year to year. Buy the Bentleys and a Durametric. Also Bentley has some mistakes in the pinouts but it gives you something to start out with.

Good Luck,

Sergiu

I have a wiring diagram for uk cars i have moved all the wires to mimic this diagram and added in 2 wires however the car no turns over but wont start. i had reordered the ignition wires. why would there be a difference and would it be to do with countries

Regards

Ross

[GTA_G20]

colors are the same 99% 996 and 986 even year to year. Buy the Bentleys and a Durametric. Also Bentley has some mistakes in the pinouts but it gives you something to start out with.

Good Luck,

Sergiu

I have a wiring diagram for uk cars i have moved all the wires to mimic this diagram and added in 2 wires however the car no turns over but wont start. i had reordered the ignition wires. why would there be a difference and would it be to do with countries

Regards

Ross

did you swap out your DME like previously mentioned???

Edited October 31, 2009 by GTA_G20

[alstarz88]

Yes i Did i have the car running now there seemed to be deviation between the engine wiring loom and the rest of the car. I had to re position some wires and add in 2 that were missing