today i relaced my leaking spider assy. with a new updated one. i got the new bracket and compared with my old bracket which was the same excpet for the 2 front tabs . i cut the tabs off my old bracket and used it instead. now i have a vacuum leak in the strangest place. the conector itself. i push down on the connector and the wistle goes away. is this a bad spider? now if i have to remove the new spider how do i get the plastic tubes out of the intake?

 

Did you do a thorough dimensional check, including the mounting bolt location between the two brackets?

Did the new spider assembly come with a new seal?

There must be something causing misalignment between the spider and the upper plenum.

 

Where did you get your spider assembly and at what price?

We are pulling the 4.3 with 524K miles and replacing it with a 119K engine that still has the OEM intake gasket. Since we are going to replace it , pan gasket, rear main seal, etc I am considering replacing the spider while it is all opened up.

 

yes i did a good comparison of the 2 side by side. they wanted you to use the new bracket becuase the old bracket unmodified interfers with the thicker fuel tubes. other than than the the main spider bodysare identical. i got my spider from advance auto parts scince thats who my eployer gets parts at a discounted price from. i paid 220 for the injector from bwd. and it was like 17 and change for the upper plennum gaskets. i did notice smoother performance and more low end power. my old spider was defective so tis is alot of the issue. back to my problem. the vacuum leak is acctualy from where the connector plugs in. i pulled off the black plastic cap on the back of the connector to cover the wires and sure enough a shot of cleaner there caused an rpm change. then after more drving that night it went away for the timebeing . so i gues i have to wait and see. if i end up replacing a defective spider how am i going to get the new fuel tubes out of the LIM?

 

The connector cannot cause a vacuum leak. If it were to leak at the connector, fuel would spray out. The leak is between the upper plenum (large plastic piece) and the spider body where the seal is. I suspect that the spider body and/or upper plenum had debris in the seal area causing the leak. Worst case is that the spider body had flash from the mold that was not removed from the seal area that is now causing the leak or possibly cut the seal.

As far as pulling the nozzles out of the LIM, just wiggle/pull and it should come out with a little force. Some of the aftermarket ones are not as dimensionally accurate as the AC Delco spiders and can have tighter fits to the LIM.

 

well the leak seems to be gone atleast for now. thanks for the info though. i cleaned the plenum really well. i thought maybe i tore the seal putting it back together but who knows. hopefully all is well and it stays good. thanks!

 

Hope it stays that way!

 

I am having a similar problem with my 1998 blazer. I had a fuel pressure problem, so I replaced pressure regulator, found a kink in fuel line so fixed that, rebuilt the spider injector, now the pressure problem is gone but I have a vacuum leak. For the life of me cannot get a good seal where the meterbody goes up through the plenum cover. I have tried using vicegrips on the back to pull while using another tool to try and lift the front up where the fuel lines go in. I took it to mechanic and he said I messed up gasket, so I got a new gasket and did it all over again. I am pretty sure I cleaned the meter body well enough.

 

whats a good safe spray to use when testing for a vac leak....