Hi, I’m a first-timer to the Forum and I’m hoping someone here can help me with a problem I’m having.
I have transplanted a 2nd generation 13B engine and transmission from a wrecked1986 RX7 into a 1978 Fiat Spyder.
The engine starts and runs fairly smoothly but not as smooth as it ran in the Mazda. It will only take about ¼ throttle before it coughs and sputters.
I have tested every sensor and connection, and traced virtually every wire and they all seem fine however, I have run into an odd thing.
The manual I’m using talks about the timing and says that when using a timing light, the “leading plugs” should fire on the first timing mark (yellow) and the “trailing plugs” should fire on the second timing mark (red).
Right now, both the “leading” and “trailing” plugs are firing on the first timing mark (yellow).
At first I thought there was a problem with the shielded wire from the crank angle sensor to the computer, being too close to the other wires that I had to route into the new car. That, I thought, could induce a voltage into the wire from the crank angle sensor that goes to the computer and that was firing the “trailing” coil at the wrong time. I separated that shielded wire from all the other wires and ensured that the “shield” was grounded to the car via a condenser.
I have two engine computers, the 326 that it came with and a 327 that I bought off Ebay when I thought it was the computer at fault. I was told the 327 was from an automatic car.
Both computers run the engine with the same timing issue.
I believe the problem is a wiring issue but I’m stumped where to look.
Can anyone there help with their thoughts?
Also, there may be a wiring issue with the trailing coils. Does anyone have a photo of the 4 wires going to the actual coils? I did some cleaning of the coils some time ago and although I think I got it back together right, I can't find a picture any where that I can check it with and so I'm thinking I may have gotten it wrong.
Don