Builds 1990 FJ62 5.3 and H55

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slow down.

why not just work on moving your ECU now so you can send it or another one out to get flashed, if you are going to do that anyways? Unless you really want to spend $500 with a local tuner who is going to be grumpy? (They are always grumpy)
 
onemanarmy said:
Thanks @cruisermatt

I'm not 100% sure which ECU I have.....the shop that did the swap mounted the ecu on the middle of the firewall with the engine right up againist it, I don't think I can remove it without taking the engine out. Its nuts how they mounted it. I for sure can't see any markings on it. I assume a gen 3....cable throttle and seperate fuel pressure regulator setup.

I plan to investigate removing it and reloating it at some point, but wanted to get a base line fresh tune on it before that.

I'll see what a ride along tune will cost me and go from there.
Click to expand...
Is it a big grey box with cooling fins on it? If you're gen 3 and drive by cable and its a big grey box that says delphi on it, its probably a Red/Blue Stock PCM. Those are the most common for the drive by cable motors. They have the IAC driver in it to adjust idle air control for the drive by cable motors. There are a few later Green/Blue PCMs that have the IAC drivers but they are far less common than the Red/Blue ones. If the motor is gen3 and its got a smaller ECM and it isnt a big grey box, its likely aftermarket

It will cost more money, but finding a good tuner will help a lot. They will connect through your OBD port and will be able to get you a good tune specific to your motor, intake, exhaust, injectors, etc. It seems like a lot of your issues like weird idle, hot starts, and bogging under load are easily fixed in HP Tuners by adjusting your idle air, fuel maps, and timing. Tuner will be able to do all of this stuff for you. Sending your pcm off for a tune is just a shot in the dark since theyll have almost no data on your actual truck and how your motor is running. On a dyno theyll be able to see everything live and make adjustments at each point in your rpm range, Make sure your transmission is shifting at the optimum time, optimize your AFR at idle/cruise/wot, adjust (not disable) torque management, etc. Think of it as optimizing your motor to run with your 60 efficiently. Its also pretty cool, they can pretty much look at every circuit that your pcm is talking to and monitor it live. The software is super super powerful. Another thing, if you do tune it, make sure to tune it for premium fuel. It will make a big difference in response and how the motor runs. Youll get 1-2 mpg better fuel economy but it isnt very noticable.

What was noticable when i switched from a "base tune" and 87 gas to a "full tune" and 93 is that the throttle response was much better and it rolled into power much better. The power at WOT was a lot better as well, as the stock tune tends to lean out at WOT so he was able to add fuel and adjust timing there. One of the coolest things is that he will run a few pulls and get your base hp and torque lines and you can see the changes the tuner does on a graph after hes done
 
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cruisermatt said:
...
slow down.

why not just work on moving your ECU now so you can send it or another one out to get flashed, if you are going to do that anyways? Unless you really want to spend $500 with a local tuner who is going to be grumpy? (They are always grumpy)
Click to expand...

I get what you're saying, however I'm fairly certain the motor will need to be pulled to get at the ECU and all the wiring and move it. The truck drives OK now, just exhibits some odd behavior occasionally. It would take me 6 months, at best, for me to pull the motor and move all the wiring and reseal the drivetrain (rear main leaks, Tcase/transmisson mating surface leaks), then dealing with the AC and all that. Its worth dealing with a grumpy tuner person to get it done in one day. The only positive is with the motor out I could easily address the leaking exhaust manifold gaskets....but I'll live with that for the time being.

Just remembered I have pics of the ECU....Its a Howell.

Fresh fuel filter, check fuel pressure, fresh plugs and wires....then get it reflashed on a dyno. Seems pretty simple.
 
onemanarmy said:
I get what you're saying, however I'm fairly certain the motor will need to be pulled to get at the ECU and all the wiring and move it. The truck drives OK now, just exhibits some odd behavior occasionally. It would take me 6 months, at best, for me to pull the motor and move all the wiring and reseal the drivetrain (rear main leaks, Tcase/transmisson mating surface leaks), then dealing with the AC and all that. Its worth dealing with a grumpy tuner person to get it done in one day. The only positive is with the motor out I could easily address the leaking exhaust manifold gaskets....but I'll live with that for the time being.

Just remembered I have pics of the ECU....Its a Howell.

Fresh fuel filter, check fuel pressure, fresh plugs and wires....then get it reflashed on a dyno. Seems pretty simple.
Click to expand...

From what ive seen from howell, is they just reflash the stock GM PCMs. Thats crazy that they put it behind the motor, but thats one way to hide it i guess haha!
 
Pic

Screenshot_20220113-105505.png
 
Thats a Po1. Nothing special.
a OEM stock tune on a completely stock engine like @onemanarmy is not a shot in the dark. That being said if he finds the right local tuner (which can be difficult). It may be worthwhile.
 
onemanarmy said:
Who knows if I have a 'stock' tune? Maybe they did some funkyness 10 years ago? It sure hunts for idle and runs a bit rich, much more than a stock 2006 tahoe would.

We'll find out!
Click to expand...
With howell, you basically give them your tire size and gear ratio and the rest of it is them guessing your tune. You have since changed tire sizes i think from reading earlier in your thread, so that will throw things off a bit too.
 
Couple things.....I was digging around last night and found a dakota digital box that is wired to my non-functioning factory tach (the PO said the factory tach worked at some point, but it just quit one day). The box is still wired up, but my tach does not work. Do factory tachs go 'bad'? Is there a way to troubleshoot, or can somoene show how they wired up the factory tach with a LS swap for me to compare?

Also, where can I buy the neat screws that hold all the front dash and radio bezels/surrounds on? Most of mine are missing.

Thanks
 
So I'm trying to diag my oil pressure gauge. It rarely moves and when it does it's a small amount and then it falls back to zero. The V8 swap has a an electric oil pressure gauge but the wire runs to the computer, not to any dash gauge wire that I can see. Not really sure why the needle moves at all. Is this the factory oil pressure wire/connection? If not, what should I be looking for? Yes, there is fresh clean oil in it. The oil pressure sender is threaded in on top of the oil filter housing...can kinda see it.
Thanks

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Original oil pressure wire is a yellow with black tracer stripe and comes out of the harness on the passenger side fender.

The original GM sender location is behind the intake on top of the block. That does nothing in your application, your ECU doesn't do anything with oil pressure data.

First step is to check the wire on your Toyota sender (the one in your pictures) for voltage. it should have 12 volts on it.

We typically mount the Toyota sensor in the original GM location as it gives the most accurate readings there, and sees the least amount of heat and road grime. it is also a lot closer to the original Toyota wiring so it doesn't have to be lengthen as much.

www.cruisermatts.com

Toyota Oil Pressure Sender Adapter LS / Vortec — CruiserMatt's Off-Road & Performance

NOTE: Be sure to use a oil-rated thread sealant on the sender’s threads when installing. Caution: Be sure to connect sender wire to CENTER POST TERMINAL on the sender. Connecting to the spade will ground and ruin the dash gauge.
www.cruisermatts.com www.cruisermatts.com
 
onemanarmy said:
So this is it I believe...and I found the splice to a solid yellow wire that runs over to the oil pressure sender. So may be best to change over to the factory location and clean up the wiring as a start. What do I need to get @cruisermatt ?
Click to expand...

Just click that link and select all options :)
 
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