Zach Scherf
Member
More troubles. After getting some help from our buddy, we saw that the plug wires were arcing in the distributor cap. So, ordered a whole new distributor. Installed it and put on all new plug wires. Started and engine ran poorly still. Attempted to time the distributor, but, since this engine does not have a vacuum line to distributor, you have to unplug a wire to stop it from advancing in order to time it ( I may have said that wrong maybe unplugging the wire stops it from retarding but you get my point). We looked all over the internet and what manual we had and found only one reference to the big trucks (gmc 7000) it said to remove the est wire or electronic spark timing wire. Where would that be? The distributor has 2 plugs going into it. One has three wires the other has 4 wires. Or do you disconnect the wire else where? Such as under the dash? Please give us a little guidance, the 366 big block with the tbi is not too common here anyways. It's also confusing because we found out the truck is a 1989 and the engine in it now is not! It is a 1990. This thing has been a nightmare to work on. All sensors on this thing have been changed except for two that no one knows what they are. It runs very rough and rich still, enough that it will foul the plugs in a very short time. Initial compression tests were good. Sorry for piece mealing out the information. It takes a long time to write out a post like this. Hope someone will have a little guidance! Thanks and I'll try to respond tomorrow as we don't have much to do except the normal chores then all day trying to fix this truck.