BeerBurner

Ok, while I was waiting for all the stuff to do my water pump, I decided to clean up and paint parts of the engine. I removed the fuel rail (and took off the injectors, fuel damper, etc) and painted that, and took off the intake manifold to scrub it down with a wire brush. I also replaced the J-boot.

I put the car back together and it's running like crap. It's holds a rev fairly well but if I back off too much or try and idle, it'll sputter, backfire and die. We have fuel and spark.

I'm assuming that some air line got knocked off and/or broke, especially since we already found two that were disconnected during the whole process. I'm going to pull it all apart and trace down all of the air hoses to make sure everything is where it should be. But is there anything else I should look for while I'm in there?

Thanks,
BB.

75ohm

While running pull each injector plug... bet one isn't working.

75ohm

One by one that is...

RedlineMan

Yeh...

You can try the injectors. You might have messed up a seal or something. I always grease them lightly so they slip in easily. It's a better bet that you created a vacuum leak. Prop the idle up to 1500 or so and take a can of carb/brake cleaner and judisciously hit areas that might leak. If the idle goes up, you found it!

Just watch your pretty new paint!

BeerBurner

We've already tested the injectors and they are all spraying. I did grease the o-rings when I reinstalled them, but I may have to double-check that as well if I can't find anything else underneath.

Oh, and I already scratched the pretty new paint. Fortunately, there isn't a lot of paint on there so it should be pretty easy to fix...

BB.

SD Porsche Fan

+1 Exact same thing happened when I pulled my rail.

tyro

I assume you put the plug wires on in the correct order?

75ohm

My biggest issue was forgetting to put the vac line from the brake booster back undneath the intake... by the throttle body.

Rock

You have a vacuum leak.

There isnt much on an N/a.

Its either coming off of the idle stabilizer, and its probably that little line at the bottom of the intake that connects to a little metal opening.

944CS

are you sure the injector CAPS are on correctly?

dgz924s

2 lines on the TB could be switched. The line to the sensor in the block near the oil seperator has 2 lines that are EZ to forget. Got #4 intake gasket on correct?( needs flipped) Correct lines to the damper and FPR, they too can be switched. Check the port on the underside of the J boot for a crack.



Check out the vacuum diagram at Clarks to verify correct line placement.

BeerBurner

I'll check all of that stuff when I have it apart.

But what is meant by "injector caps"?

BB.

Josh B

Did you replace the gaskets on the intake when you had it off?

dgz924s

The caps are the blue or yellow plastic piece that snaps on to the injector end(pintle). Freeze them before placing caps on the injectors...Tight fit.

BeerBurner

I'll check the caps while I'm in there. And yeah, I used new gaskets.

BB.