Have a few TBI questions

[tennyohpc]

I am picking up a 90 TBI setup with everything except the intake manifold.I am not sure of my engine year and what type manifold i have. The questions I have are:

1) VSS- I have read some that states its not needed but some say it is. I would rather have it though. IIRC I have a green box on the back side of my speedo. if not how does one bypass the VSS.

2) If I cant get pass the VSS issue I want to disable everything that is not needed. any advice on this.

My main goal is not fuel economy but rather a engine that will run in off camber situations. If I can achieve this while gaining fuel economy great but I don't have a wad of cash to blow on misc parts that are not really needed in my application. The truck will see very little road time mainly travel to location but will be mostly wheeled.

I have read many articles but the info seems too sparse to get a good feel as to what lay in store. Thanks in advance.

 

[dyeager535]

You've got an '85. Did it have cruise? It's already got VSS if so, you'll just feed pin A10 on the ECM connector with the signal wire from the VSS on your truck.

You don't have a lot of money you say, IF you could get your hands on a '90-91 NP241 and the '90-91 cluster, you could ditch your speedometer cable completely, which I personally prefer, but sounds/looks like yours isn't a truck you care so much about the speedometer.

 

[tennyohpc]

TBH i have no idea if it originally had cruise control. it originally had a 6.2L that someone replaced with a 350. wiring harness was gutted. I would like to keep the 205, how do you tell if the gauge cluster has the vss box? id assume its something on the back of the cluster.

 

[dyeager535]

Small box w/wires running from it, bolted to the back of the speedometer.

 

[tennyohpc]

Awesome thanks! The only thing left that might throw me for a loop is the EGR Valve. i do not have provisions on my intake for a EGR valve, i would add one if i could figure out how to hook it up. or if i can find someone to reprogram the prom to remove the EGR that would work also.

I had seen something about doing a external EGR from your exhaust to TBI body but it seemed to lack detail and at last all my searching i cant find anything with decent detail.

BTW thanks for you help. im looking forward to doing the swap but i want to ensure my rig atleast runs somewhat decent.

 

[dyeager535]

Easiest thing to actually run EGR is to simply get an intake that accepts a standard one, as long as your heads have the crossover ports.

My Vortecs don't have the crossover, I had to get a different intake, AND plumb the EGR externally. It ended up being a lot of money to get EGR working. Shouldn't be nearly as expensive without Vortec heads.

 

[tennyohpc]

i do not have vortec heads that i am for sure off and the only differance on the intake is the center 2 bolts are at an angle. like i said TBH i have no idea what year engine is in there. how do you tell if you can swap a 87 type intake on to it? I currently have the performer 2101 intake manifold on there now.

 

[dyeager535]

Well, which engine vintage is the 2101 intake listed for? Another option is to simply look at the 4 (two on each side) center intake bolts. All 8 corner bolts are at the same angle regardless of year, but the later heads have the 4 center bolts vertical, instead of angled like all the rest.

 

[tennyohpc]

ok mine is angled like the rest. i take it this means i have the older heads.. can i just grind down the flat part and enlarge the holes to use the 87 and up manifolds?

 

[dyeager535]

Yep, you sure can. Never done it, but I know a bunch of people have.