ALFAGTV6.COM

HI Everyone

I have recently insttalled a 3.0 engine into my 1981 GTV6

The problem is is won't start!

There is fuel OK

The Volt reading at the coil is the same as the battery with minimal drop however, When the 2 wires at the opposite side of the coil are attached the coil drops to @6.5volts. when one of these are disconnected the engine will spark when cranked, problem is it appears to be connected to the fuel pump relay which when disconnected dosent work.

The car ran prior to the engine transplant and I didn't re-wire any aspect of the car so I'm just stuck as to what is wrong. I've checked and cleaned all earthing points so help would be very much appreciated.

Regards

Johnny (Co. Antrim, N. Ireland)

Just a quick update, the car will actually fire up when the "cream" wire to the coil is removed but won't continue to run due to the fact when removed the petrol stops!

"Alfettaman".....Can't believe no one used that name yet!

Sounds like an unwanted circuit (either ground missing or grounded when not needed) Check all grounds, engine and beyond..

Check coil resistance and the ground wires on bottom of coil. And be sure wires to coil and ig. module are in same location and completely connected. I don't think you can mix the pos and neg plugs due to plug size... It does not take much to fry the ignition module if things are hooked up wrong.

Fuel pump switch located in air box (I think). Check one circuit at a time.
Good wiring diagrams located in owner's manual, but every Alfa I have seen is wired somewhat differently.

If you smell something burning, unhook the batt!
Good Luck! Mine was like sorting spaghetti....

Hi X-Rad

Thanks for that, I'll check those things out. I think you are probably right regarding the grounding problem. I went through Greg Gordons guide to troubleshooting the fuel injection system and found that I had earthed (Grounded) the injector wires to the bulkhead and not the engine. (This engine transplant is the first job i've ever done on the GTV6) When I changed these the engine fires up OK but won't run for anymore than a second. I have a wiring diagram now so i will check it all out in detail. if anyone needs a copy email me on jonathan@eastwoodltd.com and I can send you a copy.

Regards

Jonathan

Johnathan,
3.0's have some extra wiring. Also, sounds funny, but make sure the leads to the dizzy are in order ( not the spark wires, but the hall sensor connector)
Basically, you are chasing each circut, Then:
-did the engine run before you put it in?
-fuel pressure? fuel check valve in right direction? clogged injectors?
-cold start valve working?
-basic timing?
-main engine ground and the little ground strap from intake manifold to cylinder head connected?
3.0 ecu (recommended when you get it running)?

Take your time.......
And after all that and more, I recommend replacing the long batt lead to trunk with silicon coated marine battery cable. My old cable had several 'melt/wear through' points with frame contact.

Hi X-RAD

Thanks firstly for all your help and suggestions.

Thankfully the problem is now solved.

I checked the wiring diagrams and with limited equipment (i.e. a voltmetre) I was able to check a few things:

The problem was that the car was firing up and then simply stopping. I was able to disconnect the 7th injector and confirm that the fuel was simply being sprayed by this then stopping a second later.

I had fuel pressure and could test this by opening the flap in the AFM with the key on, I had a spark and could test this various ways, although as you quite rightly said the difference made by following Greg Gordons guide and cleaning all earth/grounding points was significant.

On checking the wiring diagram I was able to check that the 7th injector is controlled independantly of the ECU so by way of elimination I think I had potentially 4 problems:

1. ECU problem
2. Fuse faulty (2 or 7) or a relay associated within these in the fuse box
3. Combi-Relay faulty
4. Injectors clogged

Items 1-3 were easy to check because I had spares + I could test the parts out on a friends GTV6 so I thought hard about it and realised the only element of the conversion which was not on the car before I undertook the change (with the exception of the mechanicals) was the injectors!! so I swapped the original GTV6 2.5 injectors onto the 3.0 engine and hey presto it fired up no problems. This was slighly complicated because the 2.5 fuel rail does not fit straight into the 3.0 due to a slight difference in the 3.0 head on the drivers side. In saying that a vice and a few tweaks was it required to make it fit.

I'm now wondering is the any difference in the injectors between the 2.5 & 3.0 and will I experience any problems running the car. I have fitted the 3.0 ECU.

I will definitely take up your suggestion on the main cable as my car suffers substancially with voltage problems (How slow can electric windows get) and given that I plan to upgrade headlights & CD player, I need all the voltage I can get!!

I think I need to do a little research on the alternator upgrades now....

Good luck, chat again soon - I'm sure!

Jonathan

Hi there,

The injectors in the 2.5 & 3.0 are exactly the same flow rate, so you should have no problems. If you tune the 3.0 much the injectors will become too small, but for stock they're perfectly OK.

regards