Swapped to a stage 2 chip, non starter.

[hoernig]

Hi! Just a quick one, i've been given a second ecu from a friend to put my stage 2 chip in.
I got the socket soldered in no problem, popped the chip in and tested each leg for continuity to the underside of the board and all seemed good.

Swapped the ECU over and I cannot get her to start.. I can smell fuel but she won't fire. My guess would be either no spark or timing if the chip adjusts that?
I swapped the plug back to my original ECU and after spluttering for a few seconds (overfueling from the other ecu probably) she fired up and ran perfect as before.

The main question really, is a faulty chip ever heard of, or is it more likely my solering needs another go over..?
What would be the best way to test either the chip or my soldering?
Cheers

[mospin]

it could be the ecu what are the numbers on the ecu and what year is your car

[hoernig]

ohh right, which numbers am I looking at? My sx is a 92, the ecu is from an 89.

[mospin]

hmmm as it goes

facelift ecu into pre facelift no
prefacelift into facelift yes but try with your lamba unplugged

if not i have a socketed facelift ecu and i need a prefacelift socket ecu?

but try this put the socket ecu in and pull the fuse for the fuel pump till it cranks over then put the fuse in and see if it runs without the lamba plugged in

if not and the only thing you have change is the ecu then that would be the fault but im sure shyshack or jhonny will be along soon to help

[hoernig]

I know mine is a facelift on a 92, I'd guess the 89 sx wasn't a facelift?

Where would the lamba sensor be for me to unplug it? I took off my stock exhaust the other day and it had no sensors in it at all s:

[mospin]

the sensor is in the turbo elbow and runs to a plug just unplug it seems a bit strange for a facelift not to have one how many pins in the afm by the airfilter?

upto i think 1990 is prefacelift no lamba , 4pin afm
1990 onwards is facelift with lamba and 3pin afm

but im not completely sure on the above years

[hoernig]

Just checked quickly, yep lamba is on the turbo elbow, I didn't replace that when we did the rest of the exhaust so I never noticed!
Will plug in the 98 ecu again tomorrow with that disconnected and see what happens!

[mospin]

it may work with it unplugged as your using a pre ecu so the ecu is trying to read the lamba i guess but i could be wrong post up you findings tomorrow if it does run then you can leave the lamba unplugged but mot time it will have to go back on but il swap mine for yours to help you out

[hoernig]

Will let you know tomorrow yeah
The swap sounds like a good idea though, at least we both have the correct ECU's then.
If I have no luck tomorrow ill get some pics and show you this ecu, I wouldn't want to trade only to find you horrified by my unprofessional soldering lol

[mospin]

ok no problems and just for ref code on my ecu is 23710 39f05

[hoernig]

Ive just checked, both of mine are the exact same numer you posted there!

[hoernig]

Also tried the socketed ecu with lamba disconnected and no luck
Must be the chip or my soldering

[mospin]

yes something defintley wrong then best recheck your joins and make sure you havent over soldered

[hoernig]

Ill give it a go and double check them all

[Jonny Wilkinson]

The differences between the ECUs are whether it is lambda-equipped or not. A '92 could be lambda equipped or not. A UK '89 car would have been non-lambda.

If the ECU was the original ECU out of an '89 car, the code would have been 23710-44F00 yet you say it is 23710-39F05 so it isn't the original ECU from the '89 car.

If you try to run a lambda-equipped car with a 44F00 ECU it will run but not nicely. Similarly, if you run a non-lambda car with a 39F05 ECU only not quite as noticeable.

Your car is a lambda-equipped car that won't start with the 39F05 ECU you have soldered a Stage 2 chip into. It won't start because either :-

1) You have soldered the chip in the wrong way round (or if you socketed the ECU you have fitted the chip to the socket the wrong way round). If you have done this, the chip is toast, I'm afraid. You can't simply turn it round and get it to work. To find out if it is fitted the wrong way round, tell me whether the notch in the chip is pointing to or away from the nearest wall of the case.

2) The chip is fecked because whoever sold you the chip fitted it the wrong way round then flogged it on. (Doesn't apply if you bought new obviously).

3) The ECU is fecked. Only way I can think of to check this is to borrow a socketted 39F05 that is known to be good and try it with the chip.

4) Your soldering is not of a sufficient quality. Taking it to a TV repair shop is probably your easiest solution unless you've made a proper mess of it. In that case, take another 39F05 to a TV repair shop and get them to socket it for you, then make sure you fit the chip the right way round

[mospin]

Just I thought jhonny but is it possible he has put the chip the wrong way round so the pin marker does not match up


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[Jonny Wilkinson]

Just I thought jhonny but is it possible he has put the chip the wrong way round so the pin marker does not match up


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That's where my money would be.