Wrong Zone chip???

[Danstable]

My Tourer has been guzzling fuel and suffering a slight missfire since I swapped the engine and exhaust, I went from a Cat equiped late 325 engine, to a de-catted exhaust and an early 325 engine. I retained the original ECU.

Was going to get it tuned to see if that sorted it, however it occured to me that I still have my old Zone chip in there.

I wonder if the chip I bought was specifically for the later engine and so whether my problems may be sorted by either putting the original chip back in, or replacing it with another Zone chip for the earlier engine?

Are there different chips for each engine and could this be causing some problems???

[HartgeH27]

Cue Ant !!!!!!!!!!!!

The ecu you are using is not compatible, you will need to source a early 325 ECU last three numbers 073.
The one you are using will probably be a 173.

Ant will answer the chip question !!

[Templ8e30]

Cue Ant !!!!!!!!!!!!

The ecu you are using is not compatible, you will need to source a early 325 ECU last three numbers 072.
The one you are using will probably be a 173.

Ant will answer the chip question !!

Surely the early 072 ECU isn't compatible with the late injection loom and sensors ?

Cheers,

Iain T

[Danstable]

Any further thoughts anyone???

[Paul325i]

Are you saying you've fitted a late Motronic ECU to an early Bosch L-Jetronic high compression engine?

The looms for the two cars are very different, how did you get round the crank sensors etc?

[Danstable]

An early high compression engine was fitted in my 1991 Tourer in place of the original engine. ECU was left in there, so it is original (late) ECU, with the earlier engine.

As for the loom and crank sensor.....I don't have a clue! Iain (Templ8e30) is the brains behind this transplant and he assures me that the late ECU with an early engine is fine.....after all, his 2.7 has the same setup.

Hopefully Iain will be along soon to answer questions.

[Jimbob]

I have an early engine with a later engined ECU and loom, all you need to do is, either get a chip from Ant (he will swap it) for the 173 ECU or get an original 173 ECU chip.

[Danstable]

173 ECU = early engine ECU yes?

Did you by any chance run your car with the early engine and late ECU and chip? If so, did you experience horrendous fuel consumption and slightly lumpy running?

[Jimbob]

073 is old ECU
173 is new ECU

I did run it standard for a month or two and it was fine, lumpy idle but that was down to my camshaft I think.

Speak with Ant, he will swap your current Zone Chip for the correct one

[Templ8e30]

The story goes as follows :

The original 1991 2.5 engine had a suspected cracked head (later proved to be a burst water hose between the head and bulkhead ) so we pulled out the original engine and swapped it for a known good early engine.

The crank position sensor/ toothed wheel/ cam covers/ injection parts etc were taken from the original late engine and transferred onto the early replacement engine.

The original wiring loom and ECU were left in place on the car and connected up to the replacement engine.

In the process we replaced the CAT exhaust system with a non-cat alpina copy stainless exhaust system including a non-cat downpipe and binned the oxygen sensor fitting a blanking cap on the sensor socket.

I have an original 173 chip here that we can try.

I suspect that the blue engine temp sensor may be goosed as this was supplied with the replacement engine and was never tested.

Cheers,

Iain T

[Ant]

Agreed, sounds(reads ? ) like a duff coolant temp sensor

the chip should work fine, it is the correct chip for that ECU, one question though.... are you using a non-cat AFM, or worse stil the one from an 073 equipped car ??

the 073 AFM will not run correctly with a 173 ECU, the outputs wont match whats expected.

keep us posted Dan/Iain

[Danstable]

As far as I'm aware, I am running the original AFM with the original ECU.

So the chip that I bought for my late engine should be ok for the early engine that is now in there? Are there no differences?

Will change the temp sensor.....but does this supply the reading to the guage on the dash, as that is reading as normal?.....or am I being thick again

[Ant]

the bore/stroke and capacity are the same, the higher CR would enable you to run a tad more fuel to get a few more ponies but its all relative.

the blue sensor is for the ECU, the brown runs the dash cluster, its a common failing item so swop her out ASAP and re-evaluate

[Danstable]

Thanks a lot Ant, I'll source a spare and get it fitted as soon as I can.