[Zook_Fan]

I bought 94 Sierra that had a pulled apart G13ba in it. The head and sump were off, piston 4 was in the back seat. I bought a new second hand engine from Facebook from someone that had a video of it running from the day before I bought it. Came with the gearbox and everything so I pulled what was left of the engine out of the chassis along with the original gearbox and slung the replacement into the car.

Wired up the earth, alternator, distributor, starter motor and coil. The carby has been butchered to get rid of the choke and idle up equipment so all that is left is the fuel solenoid which has also been wired to the ignition. I've timed the distributor as per the FSM using the timing marks on the flywheel however these marks do not correspond to the crank pulley so I'm concerned something is off.

I gave it fresh fuel straight down the throat to try and get it to fire but once I started spinning it over it did draw fuel from the tank which could be contaminated with water, could be old, whatever. So I disconnected the fuel feed line and gave it fresh fuel from a small reservoir under the bonnet. I've also tried swapping in a good coil and leads just to confirm this isn't the issue. Car has been hooked up to a running car for all of the start attempts so it's not a voltage problem.

I've got spark at the leads. I've pulled the plugs, number 1 gets wet from fuel but still sparks, the rest seem dry but also still spark. Spark doesn't look super strong but it should be enough. The distributor is spinning, the contacts have been cleaned.

There is no air filter currently installed so there is no blockage of air.

Through all of this, the car still will not start. When trying there is a surge of fuel back out the top of the carby. The engine will spin for days without so much as a pop. I've obviously got air and fuel so I thought that there would be some sort of backfire if the timing was out but there's nothing at all, is that to be expected if it is miles out?

At this stage all I can think is that I should start from scratch with the timing. Pull the timing cover off, confirm that the belt is installed correctly, redo the distributor and see if that gets anywhere but I feel like that is unlikely. Is there anything else I should be checking?

[fordem]

I'd be checking the timing, starting with the cam timing.

[MrRocky]

Yup id redo timing belt and dizzy
However should still pop if you got fuel and spark even if timing is out.
Is the engine earthed to chassis/batt ?

[Zook_Fan]

Engine is earthed to the battery, then the distributor earths from the engine to the body.

I’ll redo cam timing and distributor tomorrow and see what happens.

[fordem]

You're getting a spark so I doubt that it's an electrical issue, but there should be cables directly from the battery negative to the body AND the engine.

[Zook_Fan]

I agree, the car seems to be functioning electrically well. The body earth was on the to do list, I’ll get it done today as well just to be sure.

[Zook_Fan]

Sure enough the cam timing was completely out. The tensioner didn't have the spring or bracket on it so I'm guessing it was jumping teeth. Swapped the tensioner out from the previous motor, retimed the cam and distributor and second spin it lit off.

Thanks for the help, should have just done this to begin with!

[fordem]

The spring is only required to adjust the tension, once the bolt is tightened down, it serves no purpose.