99-98 Ignition conversion from CDI to distributor

toatesarchitecture · Post by **toatesarchitecture** » 12 Dec 2024, 10:06

has anyone reversed a 1999 turbo 5 motor from the coil pack ingnition back to the 98 set up with coil, distributor and normal plug wires??

Engine internals/externals all seem same, and cam on exhaust side on '99 engine is already set up to take the distrbutor (plug and play) Cams look identical ECU and wiring harness is for the '98 distributor. Seems just like a mechanical switch. Am I missing something? Like changing cam sensor?? Any help would be appreciated John

Post by **Chuck W** » 12 Dec 2024, 11:17

Engine management is totally different between the 98 and 99 MYs.The ME7 ECU from the 99-04 P80 cars was never configured for a distributor.

Why would you want to change to an less efficient system?

Post by **matthew1** » 12 Dec 2024, 11:39

This is a question I haven't seen here. To me it's very interesting but impossible with the ME7 ECU. To Chuck: I'm not convinced the coils on cylinder approach was any better than distributor, at least for the HPT turbos. They were all ~18 city MPG dogs.

The upside is less cost changing coils every 120k miles, and more simplicity when troubleshooting.

toatesarchitecture · Post by **toatesarchitecture** » 17 Dec 2024, 08:55

The ecu is from the 98 motor as is the distributor, coil, wires etc. All I am using from the '99 motor is the motor. So if the ecu matches up to the distriburtor shouldnt it work - becuase at that point engine is just a dumb piece of metal that needs spark fuel and air. ??

Post by **volvolugnut** » 17 Dec 2024, 09:02

ECU will also need connection to other engine sensors like temperature, crank and cam position, vacuum, air flow, etc.
ALL sensors from new motor must talk to 1998 ECU.
volvolugnut

toatesarchitecture · Post by **toatesarchitecture** » 17 Dec 2024, 11:26

The entire wiring harness from the 98 was intact and connnected - I may have some vacuum lines mixed up but I dont have any orphan wires/connectors except for one 2 pole by the coil. I've got a seperate query string on that - someone has said it was for a diagnostic? Its only about 8" long so it had to attach to something by the air box - but I have the 98 airbox and air pipes and nothing is not connected.

toatesarchitecture · Post by **toatesarchitecture** » 17 Dec 2024, 12:58

All I took was engine block and head and turbo from 99 everything else is 98

Post by **abscate** » 18 Dec 2024, 07:13

That should work ok. There are minor things that you will have to bring over from the 98 block but nothing that isnt fixable in place.

Coil on plug is a much better system from a reliability standpoint, but the ignition on the 92-98 is great if its kept dry, and the cam seals are kept happy. All standard maintenance stuff.

toatesarchitecture · Post by **toatesarchitecture** » 20 Dec 2024, 18:11

OK so no love yet from several fronts. Fuel pump relay not working even with replacement, unless I jump terminals. Fuel injectors work with direct 12v power, but not when engine cranks. Starter sounds super slow and lethargic, but battery, terminals and wiring are good. I have a replacement starter I can swap in but that does not address no fuel at injectors when I crank engine, Thoughts???