Starting to wire and ave a few questions

[Iceburgh]

1st.... Does the PCM need a oil pressure reading? The gauges I got have to use the sending unit supplied. If the PCM needs one as well how is the best way to do both?

2. I am using a haywire kit for the truck.... I assume the ECM just gets a few power leads from the Haywire kit?

most look to be plug and play but not sure of all...can anyone make sense of the wires posted?
I did not get anything with the PCM/motor/trans but shown a video of it running so I know it does


these are coming out of the PCM
that don't have connectors on them


3 does the OBDII only have 4 wires? Will that give me readings I need and tuning capabilities ( not me but someone who knows what they are doing)

[BR3W CITY]

Originally Posted by Iceburgh

1st.... Does the PCM need a oil pressure reading? The gauges I got have to use the sending unit supplied. If the PCM needs one as well how is the best way to do both?

GenIII's don't need the OP input. GenIV want it for DOD. Its electric, so if you need it you should just be able to tap the wire for both.

2. I am using a haywire kit for the truck.... I assume the ECM just gets a few power leads from the Haywire kit?

Never used that kit but most of the good wiring kits only require 4-6 power leads connected (iirc mine was 4, and a pre-terminated 5th)

most look to be plug and play but not sure of all...can anyone make sense of the wires posted?

If we assume they used factory color coding, take a look at Lt1swap.com and the wiring harness section. Its got the pinouts and wire colors. Which ECM connector are those wires coming out of? (It looks like they might be Serial Data, TCC, Engine speed, as a start)



3 does the OBDII only have 4 wires? Will that give me readings I need and tuning capabilities

Mine's got more than 4, but I don't have access to count how many.

Ideas in bold as a start.

[ls1nova71]

We need more info. Like what year is the engine? Also, is the Haywire harness for the whole truck (main harness and you want to know how to hook it to the engine harness) or is it an engine harness?

Those unmarked wires you have if from the engine harness are like Br3w said, likley gauges, brake signal and things like that. Green one that has been stripped is probably fuel pump relay wire since they would have hooked that up to make your engine run.

The data connector only needs 4 wires, power, two grounds the serial data .

[Iceburgh]

Thanks guys.... to be honest I am not sure what year the engine is. It is a iron block 5.7 that I assume came from a truck. The whole thing was rebuilt with new guts and new intake. The guy I bought it from wired it showed me Dyno info and a video of it running then shipped it.
He said real simple plug and play. If need be I will reach out.
The Haywire is everything for the truck...used them in the past 5-6 builds and always nice to work with, however never have done a LS swap so a little uncharted waters. Gauges are speedhut and according to them I must use the sensors sold with the gauges.'

Where is the marking on the LS to figure out what year it was made?

[BR3W CITY]

Originally Posted by Iceburgh

It is a iron block 5.7 that I assume came from a truck.

Doesn't exist in any LS truck, so were not off to a great start. 4.8/5.3/6.0/6.2 were the choices

[ls1nova71]

Originally Posted by BR3W CITY

Doesn't exist in any LS truck, so were not off to a great start. 4.8/5.3/6.0/6.2 were the choices

If its a built engine, there's a chance its a bored 5.3 with LS1internals.

What does the PCM look like? We can at least figure out if its a genIII or genIV.

[BR3W CITY]

Originally Posted by ls1nova71

If its a built engine, there's a chance its a bored 5.3 with LS1internals.

What does the PCM look like? We can at least figure out if its a genIII or genIV.

True, I didn't read it that way but I suppose its always possible.

[Iceburgh]

Thanks for any help guys.
Here are a few pics maybe you can tell what I have.

[Iceburgh]

[BR3W CITY]

That looks like a Blue/Red harness, does the ECM also have "RED" on the other plug (all I can see is "BLUE")

Thats the harness from an Fbody, which would incline me to think that the electronics are Fbody.

Truck stuff is Blue/Green on the ECM connectors.

[Iceburgh]

Sure does...learn something new every day. The reason I said it is a 5.7 is that is what is stamped on the intake. Obviously it is not stock ......I can contact the sellar but it has been about a year now and don't want to be a PIA.
Did F bodies come with iron blocks?
Thanks again for the help.....this should be cool when done but this is the only area I am apprehensive about

[ls1nova71]

'99-'02 trucks used blue/red PCMs like the '99-'02 F body's. That said, that harness is set up for truck injectors, but is obviously aftermarket. F bodys never came with iron blocks, so this is a truck engine. Under where the power steering pump is, it should have a displacement cast into the block. it should say 5.3/4.8 or 6.0. It will also have it on the back of the engine in the same location, but the flexplate will be covering it. But since this is a built engine it's hard to tell exactly what year it is, but I'm going to guess it has either a 99-02 truck of F body tune in it. Does it have a 3 wire or 5 wire MAF?

[clinebarger]

What is the belt routing with that accessory set-up? Looks to be a mix-match deal? Alternator with no bracket?

[Iceburgh]

5 wire MAF
The accessory set up I dumped for a tru-track system to be bale to get everything including the A/C to fit between the frame rails and inner fenders of a AD with Mustang II

[BR3W CITY]

Can you see any #'s on the heads?



So as of now the theories are:

99-02 truck engine; either simply running a car intake, or possibly car intake and heads. Actual displacement unknown
or
Started life as fbody stuff, and ended up with an iron block for a rebuild (extremely common in fbody projects), with other stuff like the intake etc getting carried over.


So, see if you can find markings on the heads so we can see what they are, check the block for an actual displacement, and see what tune that ECM has. It could be any combo of a few vehicles.

[Iceburgh]

I get it out of the paint shop mid week. Once I get those numbers I will post them up.
Thanks again
Going back through the text from the seller ( not really info that can help here) it says
5.7 Iron Ls 485hp complete Roth trans and converter (??? not what that is unless it was to be both) new harness, ecu, maf, 02 sensors..

[BR3W CITY]

If someone said to me "5.7 Iron LS", in response to a custom build, I'd then assume that it started as a regular aluminum 5.7 and had parts transplanted to the iron truck block.

I'd be interested to see what the ECM says.