Chev Tuned Port Injection Conversion – The Finish
A quick update for those of you interested in the Tuned Port Injection conversion that we have been doing on a 350 fitted to an 80 series Landcruiser.
After deciding that we wanted the ecu inside the car and up under the dash out of harms way we spent quite a bit of time extending the wiring loom to suit. The drivers side injector wiring, temp. sensor and temp gauge wiring and the air flow meter, idle air control motor and throttle position switch wiring all had to be extended by around 100mm. Each connection was soldered and covered in heat shrink before being wrapped in convoluted tubing, talk about time consuming!
Once all that was in place the relays for the fuel pump, cooling fans and air flow meter had to be mounted and powered up and to top things off the mess of wiring from the original diesel engine was still in place so we spent quite a few hours sorting through that and cutting out everything we no longer needed. When everything was a tidied up the hole in the firewall for the ecu loom was drilled, all of the in-car wiring connections were made (or so we thought) and the ecu was mounted up under the dash to the left of the glovebox.
In the meantime Jerry had mounted the fuel pump under the floor and organised the supply and return lines. We were able to use most of the original steel fuel lines that were still there which saved a lot of stuffing around. The jury is still out on whether or not a surge tank will have to be fitted, no doubt we will know the answer to that one after the first serious offroad trip. The rest of our time spent working on the Cruiser was taken up with connecting vacuum lines, heater hoses etc etc. Nothing out of the ordinary there really.
Eventually the time came to connect the batteries and fire it up. Turning the key to the ON position brought the fuel pump to life for a few seconds – all good there. Turn the key a bit further and the starter did it’s thing but the engine remained lifeless. A quick check of an ignition lead saw that we had a nice healthy spark happening, but a check of the injector wiring revealed that we had no injector pulsing.
A couple of stressful hours were spent going over ever pin of the ecu wiring more than once until I realised that one of the omitted pins in the larger of the two ecu plugs was in fact needed for a 12V supply. The loom came with all of the unnecessary pins already removed from the plugs (circuits such as auto trans. control and a few other things) but this power supply was definitely needed! A quick wire up to an ignition source and the engine fired into life, well sort of.
The engine would fire no problem but as soon as we tried to bring the revs up it would backfire through the inlet manifold. We checked and rechecked firing order, rotor direction, ignition lead to cap placement etc etc etc. After getting nowhere for a while we decided to look for an air leak, and it had to be a big one the way the engine was behaving!
A squirt with carby cleaner around the manifold while the engine was running, if you could call it that, revealed that the revs would climb nicely when the carby cleaner was sprayed around the rear of the manifold. Somehow we had both missed a vacuum port under the manifold that hadn’t been blocked off. How we both missed that one I’ll never know.
To cut a long story short, we found a plug for the vacuum port, fired it up again and it ran beautifully. We then bled the cooling system, made sure the cooling fans came on when they were supposed to and took it for a drive. And it over-heated the whole way! They say things come in three’s. The further we drove it the hotter it got so we decided to pull the radiator the next day and have it cleaned out. Turned out it was 45% blocked and now that it’s all sorted it runs between 150-180 F on the gauge – beautiful!
Was the exercise worth it? Hell yeah! The drive-ability of the big Cruiser has improved dramatically. It idles nicely, starts first turn of the key every time and has a nice smooth power curve right across the rev range. It feels like the power output is up considerably from the carby setup, I doubt that any time had been spent tuning the carby to the engine so that’s hardly surprising I guess.
If you are thinking of doing this install to a carby-fed Chev I highly recommend it, just be sure to get all of the power supply’s to the ecu wired up and look for any unblocked vacuum ports in the manifold, doing this will save you hours of frustration!