HELP! Smallport 4age.... No idea whats happening!

[Truenotch]

Just got the motor into my mr2, we've done everything. Cool ready to start up rite? Nup... Turn the key and all's you get is a screamin starter motor, pistons goin round and injectors squirtin petrol all over the block.

Took out a spark plug and cranked the engine over again, seems theres no compression????

cranking over it sounds like the starter motor isn't even connected to the flywheel, but the pistons are movin and its spinnin over way too fast.????

I have no idea what to do. When we put the crank pulley on there was heaps of compression (was hard as to turn it), but now theres nothing.????

Anyone know anything????

Oh and also does anyone know how to swap injector plugs over? I need to get the bigport plugs off my loom and replace them with the smallport ones....

Any info would be great. Cheers

[RedMist]

You didn't change the cam belt did you? Or piss with your cam timing? Unusual that an engine will loose compression on all four, unless you have something like a cam belt issue. But it certainly sounds like no compression. You could take off a rocker cover and check the cams are rotating (by turning the engine over by hand).

[pc]

Assuming it was ok when you turned over by hand, You probably didn't put enough tension on the tensioner and it's jumped lots of teeth on the cambelt when turned over by the starter. You probably have no compression cos a set of the valves are open on the up stroke.
How did you get fuel squirting all over the block tho... fuel line not done up?

[Truenotch]

Assuming it was ok when you turned over by hand, You probably didn't put enough tension on the tensioner and it's jumped lots of teeth on the cambelt when turned over by the starter. You probably have no compression cos a set of the valves are open on the up stroke.

Yeah I think thats probably it... We put a new cambelt into it but set all the timing back to how tha haynes manual said it should be, so probably didn't put enough tension into the belt.

How did you get fuel squirting all over the block tho... fuel line not done up

I think the injectors we are using, the bluetop ones (because thats the loom we have) are a smaller than the redtop ones, so there was no seal around the injector and petrol squirted everywhere. But I have no idea how to switch the plugs over to run te redtop ones???

[RedMist]

Aren't those injectors different impedance?

The are certainly different flow rates. Which means you must match it to the computer they were designed for, or somehow fool the ECU to inject much less fuel.

[ChaosAD]

I thought those injectors had different plugs.
You should be able to see the cams when you take off the oil cap. Have a look through the oil cap while a mate turns over the engine.

The spring on the tensioner should provide all the tension you need.

[Truenotch]

I thought those injectors had different plugs.

Yeah the plugs are different, but I want to run the smallport redtop injectors rather than the bluetop ones.

The redtop injectors probably wont work on the bluetop ecu as the redtop ones are 2 ohm 235cc and the bluetop ones are 1 ohm 182cc.

I just want it to run untill I can figure out how to get the redtop loom/ecu running the engine and the bluetop loom/ecu running the rest of the car as I have the redtop ecu and loom (the redtop loom is cut and will run the engine only).

[matt dunn]

The spring on the tensioner should provide all the tension you need.

Should, but sometimes doesn't.

I usually give a wee push on it to get a bit more tension on the belt.

And make sure the tensioner is free to move too. Not just the bearings but the tension movement.

Matt

[Truenotch]

We reset the cam timing. Seems we had set it wong orgionally and now its running, and running damn well at that.
Cheers for the help guys.