Calling all 400 se owners
Discussion
Too cut a long story very short my new gearbox is now in and the car is running but only on four cylinders it has been narrowed down too the ecu, but the previous owner swore on his mothers life that it was running fine before it went back too the garage with an expired gearbox so I am suspecting that as it was parked in there workshop for a couple of months the barstewards have swapped the ecu over with another car, so the problem I have is I am not sure if the ecu thats on it now is the one it should have so it would be greatly appreciated if some of you guys with 400s could tell ne what part number is on yours just too make sure I get the right one mine is an 89 on an F thanks in advance Mark.
Is it hotwire or flap injection?
The flap system is prone to a blown transistor that takes out all four cylinders on one bank, I think the hotwire is sequential so it shouldn't happen.
If it is the flap system fault, it doesn't prove the ECU was swapped; after 18 years transistors are entitled to get a bit tired...
The other possibility (again wrt. the flap system) is that the injection reistor pack has two 12v feeds to it (diagonally-opposite corners of the connector, brown/ orange wires IIRC)... if one of these has a poor connection to the resistor pack, then again you lose four cylinders. As a start, try plugging and unplugging the resistor pack connector a few times.
It's the right type of weather for oxidising connectors, right about now...
The flap system is prone to a blown transistor that takes out all four cylinders on one bank, I think the hotwire is sequential so it shouldn't happen.
If it is the flap system fault, it doesn't prove the ECU was swapped; after 18 years transistors are entitled to get a bit tired...
The other possibility (again wrt. the flap system) is that the injection reistor pack has two 12v feeds to it (diagonally-opposite corners of the connector, brown/ orange wires IIRC)... if one of these has a poor connection to the resistor pack, then again you lose four cylinders. As a start, try plugging and unplugging the resistor pack connector a few times.
It's the right type of weather for oxidising connectors, right about now...
Sorry to hear your troubles. From the beginning of Wedge ownership I have always thought that if the EFI needed any money spending on it I would junk the lot and replace with Megasquirt. I think for the sort of money you mentioned you could justify it in one hit! Worth thinking about as an alternative to shelling out to "repair" part of your aging system.
dickymint said:
Don't know much about hotwire myself. But I would doubt that you need to shell out £350 to sort it. I would find somebody local on here and see if you can try their ecu on your car first.
Thanks guys and you just gave me an idea I know someone else with a 400 and see if I can borrow it for 10 mins.
if you can get a ecu from a range rover brackers ive got the eprom chip for a 400 se from my tvr 400se ecu when i upgraded to a mark adams chip
my 400se is a hot wire system if this helps
also a possibull phone no for the ecu is ;
rovermania in birmingham on 0121 328 1113 say steve from auto audio sent you
hope this helps you
my 400se is a hot wire system if this helps
also a possibull phone no for the ecu is ;
rovermania in birmingham on 0121 328 1113 say steve from auto audio sent you
hope this helps you
s.hogan3 said:
if you can get a ecu from a range rover brackers ive got the eprom chip for a 400 se from my tvr 400se ecu when i upgraded to a mark adams chip
my 400se is a hot wire system if this helps
also a possibull phone no for the ecu is ;
rovermania in birmingham on 0121 328 1113 say steve from auto audio sent you
hope this helps you
my 400se is a hot wire system if this helps
also a possibull phone no for the ecu is ;
rovermania in birmingham on 0121 328 1113 say steve from auto audio sent you
hope this helps you
Thanks steve.
wedg1e said:
Is it hotwire or flap injection?
The flap system is prone to a blown transistor that takes out all four cylinders on one bank, I think the hotwire is sequential so it shouldn't happen.
The flap system is prone to a blown transistor that takes out all four cylinders on one bank, I think the hotwire is sequential so it shouldn't happen.
Hate to contradict you Ian, but the hotwire system is bank fired too. If it helps at all there's wiring diagrams for the hotwire loom in this thread www.pistonheads.com/gassing/topic.asp?h=0&f=&t=243015
If you think you're being taken for a ride thinking the ECU is FUBAR, check the wiring out first.
Regards
Iain
Limey 666 said:
Yes the thing is that info came off the bloke that owned it for 10 years so I didnt question him about it I wrongly assumed he must know anyway sorry again.
Not all Wedge owners are as clever as wot us lot on here once were bfore the sound of te v8 scrambled our brians! I tink.
hormone said:
Limey 666 said:
Yes the thing is that info came off the bloke that owned it for 10 years so I didnt question him about it I wrongly assumed he must know anyway sorry again.
Not all Wedge owners are as clever as wot us lot on here once were bfore the sound of te v8 scrambled our brians! I tink.
I wish I could get my brain scrambled by it Brian but they sent the ecu away somewhere down country and they have shut down till after christmas etc so I cant get the serial number so I can find another one and I am totally f###ed off.
chassis 33 said:
Hate to contradict you Ian, but the hotwire system is bank fired too. If it helps at all there's wiring diagrams for the hotwire loom in this thread www.pistonheads.com/gassing/topic.asp?h=0&f=&t=243015
If you think you're being taken for a ride thinking the ECU is FUBAR, check the wiring out first.
Regards
Iain
No, contradict away; I never claimed to be an expert.
Actually, looking at that circuit, the injectors seem to be tied together near the injectors themselves. with just one wire going back to the ECU. So a break in that one wire would take out 4 injectors... at least on the flap system each injector is routed to the ECU separately so a break might take out one but not 4...
Limey 666 said:
I wish I could get my brain scrambled by it Brian but they sent the ecu away somewhere down country and they have shut down till after christmas etc so I cant get the serial number so I can find another one and I am totally f###ed off.
Don't panic too much: if you want a spare ECU for test purposes you will find that any of the flap system ECUs will work TO SOME DEGREE... so find an SD1, Range Rover etc and there will be a Rover part number 'PRC' and 4 digits. 4764 and 7440 are the two most common; the SD1 used another one that Jim or someone will remind me of shortly...
Sometimes there's the Lucas number instead of or as well as the Rover number: typically 84477D or 83986A. The latter is from an '86 Wedge so almost certainly an SD1 unit.
The unts differ primarily in that certain resistors in the unit were changed to match fuelling requirements of the car; consequently any electronics techie with half a brain could swap the resistors in another ECU to match those in your original one and you'd have a near-identical part. About an hour's work, fifty quid tops.
wedg1e said:
No, contradict away; I never claimed to be an expert.
Actually, looking at that circuit, the injectors seem to be tied together near the injectors themselves. with just one wire going back to the ECU. So a break in that one wire would take out 4 injectors... at least on the flap system each injector is routed to the ECU separately so a break might take out one but not 4...
Actually, looking at that circuit, the injectors seem to be tied together near the injectors themselves. with just one wire going back to the ECU. So a break in that one wire would take out 4 injectors... at least on the flap system each injector is routed to the ECU separately so a break might take out one but not 4...
YUP that's correct there is only one ECU pin per bank, the power is fed from a single relay feed too, which means a break in that removes all 8 injectors.
Regards
Iain
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