MPFI spider injector swap/upgrade info and questions thread

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Sampuppy1

Diesel nut
Joined
Mar 26, 2013
Messages
10,856
Reaction score
1,223
Location
West MI
I see threads occasionally about this. I just recently did this swap on mine and figured I would post some info I learned with my experience. Also thought this would be a good central location for people to ask questions and troubleshoot all in one inclusive thread.

For starts, some info about this system.

Originally the 96+ vortec trucks came with a central fuel handling body where the lines go in and the fuel pressure regulator is located. 8 lines branched off this central unit like spider legs and were finished with poppet style injector tips that operated similarly to a clicking pen.

They worked fine for many years but with egr and other crud in the intake these units would begin to experience failure due to debris. The plastic lines would also crack and leak and they cause all sorts of issues.

They normally are removed in condition similar to this.
You must be registered for see images attach


The solution for this was to utilize electronically fired injectors in place of the poppet style tips. The fuel metering would be handled there and is an all around better design.

Delphi was one of the main manufacturers of this updated part and to my current knowledge they are the only one left making new ones. Echlin may make them but I have no way to confirm this without purchasing one and physically inspecting it.

Which brings me to my next point. Many of the stores (AutoZone, Napa, Advanced, O'Reilly, and such) all sell house brand ones be it Duralast, echlin, etc. I have yet to find an in stock part I can physically look at to see who manufactures it. BUT, all these stores, as well as many online retailers do carry the ACDelco brand spider for $200-500 as well as the Delphi brand spider at prices ranging from $450-900. Brick and mortar locations as always tend to be pricier. eBay and online retailers can vary but you can generally get parts cheaper online with free shipping to boot.

This is where it gets fun. Delphi sells their unit to other companies to be Reboxed and sold under other names. ACDelco is one of these companies. Borg Warner is another.

If you get a chance to look at a spider injector setup in store, do so. There's a few key components that will tell you if you're getting an 800 buck Delphi unit for a zinger of a deal, or if it's a house brand you could take a swing on and miss.

One of these is the main body itself. Where the plug sits is a series of numbers. The updated Delphi unit uses the same main body but with a few modifications to accommodate for the new injectors and tips. If the body numbers match the one that's on your truck, it's likely a good sign you are holding a genuine Delphi part.

Here is the stock part 17091626 PA-86 GF33
You must be registered for see images attach


This is the Delphi spider unit
You must be registered for see images attach


The injectors themselves are the dead giveaway here. I bought an ACDelco unit and the injectors themselves say Delphi right on the grey plastics where the wires go in. Might be hard to see but it says Delphi right on the units.
You must be registered for see images attach


I got my spider off Rock Auto. Basically was a kit that included an entire gasket set and a new bracket for the spider. Came with everything I needed to do the job. Costed less than $300 for me.

Here's pics of all the parts with numbers for reference

The spider itself comes with a new o-ring
You must be registered for see images attach
ACDelco pn 217-3029 or GM pn 89060440

Also included with the rock auto setup was a new bracket
You must be registered for see images attach
same for gm and ACDelco. Pn 93442096

And a complete upper intake plenum gasket set
You must be registered for see images attach
gm and ACDelco pn 17113206

I used everything in the kit that rockauto sent. Made the job very simple and made it so I didn't have to question any of my gaskets being used twice. Install was fairly straightforward. Took about 4 hours or so. But I did plug wires and some other stuff as well. In reality it's a two hour job start to finish for a proficient person.


Common symptoms of a failed poppet spider include piss poor fuel mileage, raw fuel smell at idle, random misfires, stumbling, amongst many others. I had most of the common ones. The spider fixed most of the ones I could tell from until it decided to stop running.


I'm very pleased with it so far but I have encountered other issues that have impeded my ability to do a full review. Once I resolve those issues I will update this post.







Sent from my flagged XT1635-01

Tyler/T-Unit
 
Last edited:

Jiggie

OBS Enthusiast
Joined
Jun 13, 2017
Messages
54
Reaction score
12
Location
Kansas
Im afriad ima have to do this to my 99 burb. 3 shops including the dealership misdiagnosed my stumbling issue, saying i needed new cats. Replaced the cats and still having issues. Soo tune up and this spider conversion is next. Hope i can find a good how to video or write up on how to do it because i don't know if this is something im able to do myself.


Sent from my iPhone using Tapatalk
 

Sampuppy1

Diesel nut
Joined
Mar 26, 2013
Messages
10,856
Reaction score
1,223
Location
West MI
nice write up, certain a few of us have this in our futures
Thanks. I tried to cover everything on it. Got my other issues resolved so I should have a full review by this coming weekend.
Im afriad ima have to do this to my 99 burb. 3 shops including the dealership misdiagnosed my stumbling issue, saying i needed new cats. Replaced the cats and still having issues. Soo tune up and this spider conversion is next. Hope i can find a good how to video or write up on how to do it because i don't know if this is something im able to do myself.


Sent from my iPhone using Tapatalk
It's a very simple task. Able to be done with nothing more than a couple screwdrivers, 1/4 drive ratchet, extensions and 8,10,11,13 mm sockets and maybe a 15mm all in deep and shallow well styles. It's a three hour job. Take your time,

Sent from my flagged XT1635-01

Tyler/T-Unit
 

redfishsc

Tired of fixing lousy engineering.
Joined
Nov 7, 2016
Messages
514
Reaction score
242
Location
South Carolina
I'm about to order a set of these. If I'm ordering from Rockauto, am I more likely to get the better unit from an AC Delco, or Airtex? They have the Delphi brand but it's a lot more.
 

east302

I'm Awesome
Joined
Oct 4, 2013
Messages
3,407
Reaction score
3,121
Location
Jackson, MS
I used the Delco version in 12/2016 and have had no issues. I read somewhere that it's actually a re-boxed Delphi version.


Sent from my iPhone using Tapatalk
 

Sampuppy1

Diesel nut
Joined
Mar 26, 2013
Messages
10,856
Reaction score
1,223
Location
West MI
I would go with delco. It's a reboxed Delphi.

Sent from my flagged XT1635-01

Tyler/T-Unit
 
Top