4age Cam timing question, what to do? Options

[94silverst]

What do I do about the adjustable cam timmer on the new engine if I'm using the 7afe ECU? Is there anyway to hook it up so it works right?

[Coomer]

What are you trying to do? Without more information we can't help you.

[94silverst]

Well, I'm swaping the 4age for the 7afe just like you did. However, when I hooked up the 4age ECU nothing ran, so I hooked the 7afe ECU and it started and ran for a while so I decided to use the 7afe ECU with the 4age engine. Now, the cam timmer in on the front of the engine above the power steering. I'm sure you know what I'm talking about (if you need I can post a pic). Anyway, the 7afe wiring harness does not include the cam timming unit (because it didn't have one). I has two wires, I'm guessing power and ground, which comes on around 4500 RPM i've been told. So what do I do about it? I obviously want to use it but don't know how I should go about it. Coomer, what did you do? did you use the 4age ecu or the 7afe and if you did use the 7afe how did you hook up this unit. Any info on this would be very helpful on this! Thanks!!

[Coomer]

So when you say 4A-GE I'm assuming you mean the AE101 silver top 20V 4A-GE. And I'm assuming that when you say "cam timmer" that you mean the intake-side VVT cam gear, which is activated by the solenoid on the exhaust-side of the head.

You shouldn't be using the 7A-FE ECU for the 4A-GE. Even though the car may run, chances are that it's not running anywhere near correctly and you'd have much bigger problems than just having VVT not working.

Does the car actually move under its own power with the 7A-FE ECU?

Basically, the 4A-GE ECU gives the VVT solenoid a ground signal based on the TPS signal(above 80% throttle or so) and RPM signal(VVT doesn't operate after approximately 7,000 RPM, but it does operate below 4,500 RPM, at least on my ECU.) The other wire going to the solenoid is ignition-switched +12 volts.

So I guess you could wire the ground wire of the VVT solenoid to a switch and enable the switch to enable VVT.

What I'm not sure on is whether the 4A-GE's ECU dumps more fuel into the engine when the VVT is switched on, or if it dumps more fuel into the engine based on the TPS signal. Might be something you want to look into, though I dunno if you'd find much information about this.

What's important though is getting the car running well. VVT isn't near as important as having your engine running right, and I couldn't imagine the AE101 4A-GE running correctly off of the 7A-FE ECU.

[94silverst]

Okay....So how did you go about wiring the 4age? The 7afe harness fits into the 4age ECU, but i'm not sure if that would work. Do you basically suggest that I use the 4age ECU and Wiring harness? It's probably the best way to go I know. If you did do that, did you do it yourself or have someone wire it for you? Thanks for all the feedback!

[Dr_Tweak]

In order for the 4AGE ECU to work, the entire engine harness has to be rewired. Parts from both the 4AGE and Celica harness have to be used. I offer this service, in fact I actually just did a harness for someone swapping a 4AGE 20v into a Celica ST, and it started up first try. (As usual )

The cost is $350 plus shipping and I'm currently booked through into April.

-Doc

[94silverst]

Thanks DR Tweek, if I can't figure it out by then I will use your professional services.
Does anyone have ECU diagrams? Or wiring diagrams for these engines? If so let me know it would be a huge help!! Thanks

[Coomer]

Thanks DR Tweek, if I can't figure it out by then I will use your professional services.
Does anyone have ECU diagrams? Or wiring diagrams for these engines? If so let me know it would be a huge help!! Thanks

They're all over the web. If you do a search you'll find them.

[94silverst]

Thanks Coomer!