MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - Fuel injection repair

As some of you know, I went to the V8 meet in Townsend in the yellow GT instead of the maroon roadster I wanted to drive, as the FI system in the roadster decided to take a dump. All is well as of tonight, but I though I would share so someone else would not have to go through the learnng curve.

Original problem was solved with a new relay. http://www.autopartswarehouse.com/ This was the source of new relays for $15.00 and change, very prompt shipping. As Nory used to say, just because you found A problem, does not mean you found THE problem.

Next problem was that as soon as the car got to normal operating temp, is started to die. It would idle, but not run. If forced to run a bit, it would backfire as if it was starved for fuel.
Well, I changed the fuel pump & filters, no help. I next changed the coolent & fuel temp sensors, no help. I changed the MAF, still no help. I went for broke, changed the coil, cap & rotor. Nothing changed, but I was running out of spares to swap. Someone I was talking (crying)to suggested it was the ECU.

That had to be the problem, as there was nothing else left to change. I had a sudden brain flash, the only one of this trial. I disconnected the temp & fuel temp sensors, and started the engine. It ran O.K., not great, but O.K. It was running in open loop, proving the ECU was bad, as it would not run in closed loop, with everything connected. New ECU, all is fine(so far).

Moral: to check for a bad ECU, disconnect the sensors & drive the car.If it runs with no sensors, won't run with them connected, bad ECU.


Jim Stuart

Jim
That's really useful advice - I am sorry you had to learn the hard way but thank you.

FWIW - In 40 years with MGBs I have had a spare fuel pump and coil for at least 38. I have needed both and other MG owners have also benefitted from the coil. - when I converted to FI, an ECU was added. Sods law will determine that the only things which let me down will continue to be the Alternator and starter but any way you look at it, a small outlay in parts dramatically increases reliability.

Roger
Sunny London - 90F.
RMW

This thread was discussed between 18/07/2006 and 21/07/2006

MG MGB GT V8 Factory Originals Technical index

This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.