Backwards spider injection

[likestrucks]

Had a new engine installed a few months ago. Since then it has been running a little rough. The engine kicks at idle a little, as well as when driving on occasion. The engine was installed at a GM dealer. I took it to a different GM dealer for diagnosis. They said that when they disable an injector that the engine will miss on the opposing cylinder, they said the only reason they could see this happening is if the spider was installed backwards. I took the truck back to the first GM dealer and gave them the diagnosis and asked them to fix it. They are now telling me that it is impossible to put the spider in backwards.

My question is can it be installed backwards, and if so will it permanently damage the spider?

Thanks.

Jarett

 

[DGA1]

I can see it being installed backwards if they are not careful.

Here are the pictures of the old and the redesigned one. See how they are all the same length? The injector holes are grouped in pairs as well and getting them crossed would be pretty easy actually.

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[likestrucks]

It does look that way, thanks for the reply. Based on the diagnosis, it seems that all the ones that are grouped are switched. When #1 is disabled, #3 would miss. When #2 is disabled #4 would miss. When #5 was disabled, #7 would miss, and when #6 was disabled #8 would miss. And vice versa for all. This is disabling of the injectors, not the plugs.

 

[DGA1]

It sounds like the problem to me. If you were just doing the replacement of the injectors, not following a manual, and riding on intuition and luck you'd get them crossed easily, since the outer 4, coming from the main spider body go to cylinder 1, 2, 7, 8 and the inner 4 to cylinder 3, 4, 5, 6. The manifold actually has little stamps by the injector hole indicating which cylinder it is and if I remember correctly the injector assembly has corresponding numbers on it as well.

Yeah, I'd show em some pictures and draw them a diagram if need be for them to fix this. Luckily there is not much to mess with taking off the upper manifold to fix this.

 

[skylark]

The connector has the lines numbered.

 

[likestrucks]

The results came back, after they had the truck for 2 days they finally came to the same conclusion that the other dealer came too in half an hour. The lines were going into the wrong ports. The truck runs like a top now, I am glad I didnt have to fight them too much on this. I took it back to them first and they were trying to tell me it was a tranny issue. They didnt look deeper into it until I got a second opinion from another dealership.

 

[bluex]

Wow, I hope there was no charge involved with making this right an a big apology....

 

[agent319]

I'm thinking I may have the same issue. I recently had my intake manifold gasket replaced and about a month after I got the truck back it started stubling (intermitent miss) like the OP. My question is when the shop replaced my intake manifold gasket did the spider injectors have to be removed? Because if they had to be removed they may have installed the spider injectors incorrectly.

 

[am92]

If it ran fine for a month then I doubt that's the problem...that would have caused trouble right away
It could be that the spider is going out (sticking) if its original, but it doesn't sound like it was installed incorrectly

 

[agent319]

If it ran fine for a month then I doubt that's the problem...that would have caused trouble right away
It could be that the spider is going out (sticking) if its original, but it doesn't sound like it was installed incorrectly

If it is sticking what will make it unstick?