ok guys...i just got my TPI setup in the mail today, and ran across a problem.....the TPI was from a 86 or 87 trans am...and i believe they had the eletronic driven speedos...and i am trying to put it into my 84 z-28....what all do i have to do to get this harness to work in my car??? please help

 

also wondering if there were any other differences in the pontiac TPI from the chevy TPI systems that i may run into??

 

On my 1971 with TH700R4, I went to Stealth Conversions and picked up a retrofit type vehicle speed sensor. It allows me to run the vehicle speed sensor and my mechanical speedo. I forgot the part number, but give them a call.

 

If you're new set-up is going on an 84 Block, with the stock heads, then you're set-up is definitely from an 86 (non-centerbolt style TPI intake). If this is the case, then I'm pretty sure that you'll be fine.....as electronic driven speedo's normally came on later models.

 

well..i know that i am going to have to modify the manifold for my heads...and the Tuned port came off an 87 formula...which is deffinatly an eletronic driven speedo....

 

as it stands, my main problem right now is the fact that on the wiring harness, there is no plug that fits into the cluster like on my old harness...i am pretty sure it's cause of the eletronic driven speedo, but i am not sure if pontiac had a different setup than chevy other than that...

 

What plug from you're old harness? Where did the 84 plug, plug into on the 84 cluster? I'll check the 87 schematics for you right now.... give me a few minutes.

 

it plugged into the firewall on the drivers side...was a big plug...maybe 2" by 2"...square looking plug

 

I'll still check the 87 schematics for you.... but I'm pretty sure they weren't electronically driven until the advent of 'Speed Density' in 1990.

But anyway, exactly what did you get in the mail (as far as the harness), did you get everything.... even the 87 fusebox?

 

no fuse box. got the fuel rails, plenum, manifold, runners, Throttlebody, a broken MAF heh, wiring harness, ecm, distributor, and fuel injectors..we checked the harness over, and it has everything i need..except the plug to plug into the cluster...it had all the sensors and the fuel regulators and such. And i remember reading on the t-56 retrofit page that they started the eletronic driven speedos on the firebirds in 87...so i'm sure of it that this harness is for an eletronic driven speedo...just didn't dawn on me till i looked at the harness that it wouldn't work... even after he told me it was from an 87 forumla heh

 

This is where I'm a little confused. On a TPI harness, the only wiring that by-passes the ECM is the ALDL wiring, as well as the Fuel pump wiring. When you say that you have up to the ECM, do you mean you only have the ECM forward (meaning the ECM, and wiring exiting from the ECM, via the fender well.... into the engine bay)? You don't have the TPI ECM connectors coming 'from' the fusebox, leading to the ECM?

As for the plug, that originally plugged 'into' you're 84 cluster.... where did it plug into it? The only wiring from the ECM harness that leads to both the 84, as well as the 87 cluster, is for the SES light, ALDL, Fuse Box, and vehicle speed (but this does not make it 'electronically driven' though, the VSS speed sensor is for proper operation of the torque converter).

The use of a 'buffer' for vehicle speed, did not occur until 1990 for both Pontiac and Chevy. Maybe the reason why it's said that Pontiac is different from Chevy in the late 80's, is because some models of Pontiac's came with a digital dash. Other than that, you should be fine I would think.

If you're ECM demands a connection, you can always install a by-pass.

(just to note, VSS Vehicle Speed Sensor found by the cluster is for the Torque Converter)...

 

well...my car is a 5 speed manual..and the guy i bought my TPI setup said the formula was a 5 speed as well....i have the fuel pump wiring. The plug i am talking about (one of my harness i have in my car now, which is a 4 barrell carb) is on the other side of the ECM wiring at the end of the harness. One of my friend's dad is helping me put it all together, for my friend had TPI put onto her car...and we were out looking at the harness, and he said that it didn't have the plug that plugs into the firewall to the cluster, which i looked on my orginal harness and i did not see any plug that looked anything like it. http://www.skulte.com/T56.html and this is that page i was talking about that i saw that 87 firebirds had eletronic driven speedos....anyways, i think i have successfully confused myself lol

 

You just answered you're own question.

You said you're friends father helped her do her TPI swap.... but was you're friends car an automatic???

He might be referring to, and looking for the VSS sensor, in which since you're car does not have one, he won't find it.

 

what does the VSS look like? and where can i get the items i need to make it work on mine?

 

i'm still kinda lost...cause i didn't see the plug that would go to my cluster at all..unless it is alot smaller than it was on my old harness

 

You don't need it. The VSS is utilized to inform the ECM when to lock-up the torque converter (automatic transmission).... and since you have a 5-speed, it doesn't apply to you.

 

where can i find the by-pass or buffer or what ever i am needing?..and i am still kinda lost..for i still don't know what plug would go into my cluster...

 

Kaas, since you purchased an ECM and wiring harness from a model that aready utilized a 5-speed.... then you're all set! Now, if you're harness came from an automatic (which it didn't), then you would of had to find a by-pass.

You're all set....

 

then how do i get it to plug into the cluster? lol...for i did not see any plug big enough to fit into the back of it...

 

Remember Kaas.... you have an 84 cluster. TPI came out in 1985, so plugs, connectors and fittings are very different compared to an early LG4 (carburetor) model.

BTW, what are you trying to plug into the cluster? The only wire leading from the ECM to the cluster is the SES light?

 

i am not quite sure lol...i am just comparing it to the old harness i had...and like i said, it was a big plug...bout 2 inches by 2 inches. so, am i going to have to buy an 85-90 cluster, or am i going to have to splice something into my harness? what am i going to have to do to get it to work?

 

Now I know what you're talking about. The connectors that are 'locked' into the dash (behind the cluster), that the cluster get's 'pushed' into, right?

Then yes.... you'll need a newer cluster, one that is compatible with the 87 Pontiac's cluster. But to be honest, if I were you.... just get a connector from the junkyard, and re-route you're existing wires (with new terminals of course). It's easier this way.

 

so, how would i do that? and what kinda harness would i have to chop on to get it?

 

do the firebird clusters fit into camaros? till i can at least figure out what else i wanna do lol...really really wanting to get my car up and running..been driving a 4 cylinder for to long -shutters-

 

Each wire is categorized by color, and on the connector.... they are normally indicated by a letter. You'll need to identify EACH wire that originally (stock) went into you're existing cluster.... then identify the ones on you're new harness. Once you match them up, place the proper wire, in their proper slots on the connector (as they vary, some are for gauges, some are for lighting, SES light etc...).

If you do it this way, you'll need the COMPLETE schematics for both the 84 LG4, and 87 TPI.

This can obviously be avoided if you go with an 87 Z28 cluster.... as the fitting should be the same. GM normally utilized the same connectors on each of their models for the same year, and with the same engine (especially between Z28 and TA)....

 

i think i would rather just splice in a connector or something...for the 90-92 speedo clusters (which i am thinking is the kind i will have to get) is ugly as sin

 

hmm...well, i think my friend has an newer cluster not in a car that i can look at

 

They don't. You'll need to bring the connector that you're using to a junkyard, then find an 87 Camaro/Z28/IROC cluster. Pull the cluster out of the junkyard car, and see if they mate up.

If they don't, then you'll have to re-route the wiring into the original connector (after you determine which wire goes where)....

 

The 90-92 Z28 cluster's are the one's you want to avoid, as these are the 'electric driven speedo' type. Find yourself an 87-89 Z28 cluster, but first make sure that the connector fits...

If it doesn't, believe me... re-routing the new wires into you're exisiting cluster and connector will be easy. You'll just need a 'terminal removing tool', a schematic book (which I can help you there).... and patience.

It's very easy, trust me!

 

ok, i'll see if i can find a cluster to try it out on..think i need to find an 85 thru 89..which i think were all the same

 

since it's you and me pretty much talking back and forth...you happen to have an instant messenger that i can try and talk to you on? like aim or yahoo or something?

 

Actually I don't.... but PM me, as the personal messages go right to my e-mail, which I check all the time.

 

if that is the case..with the clusters and such, i just thought of something...how would i go about doing that, since i believe the clusters of the later years were higher mph than my 85 mph cluster...what all would i need to change to get it to be able to go up to 145 or 110 or whatever i end up getting for mph