Speaking specifically about the engine wiring:
With wiring my car 'looming' on the horizon (bad pun), has anyone here ever re-used a stock wiring loom for the 16v tvis 4age? If you used the 4age, did you rewire from scratch, or did you re-use certain parts of the original loom?

Any helpful tips or maybe websites with 4age wiring info?

Thanks

Graber

I plan to use a modified MR2 harness in my car when I get to that point. For more info go here:
http://128.143.134.116/aw11parts.asp#electrical

There are a number of MR2 specific wiring diagrams. These diagrams should get you some useful information though.

Bill J

[Edited on 8/8/03 by mrmotorhead13]

I am just starting to wire my 1987 TVIS-equipped 4AGE. I'm going to clean, re-wrap and re-use the stock loom as it's got all the connectors for temp and pressure senders, ECU, alternator etc etc. I will install a new fusebox and relay box, leaving out all the unnecessary stuff for heated rear window, electric windows, sunroof and so on.

I've only got as far as fitting the battery main feed cable and engine/chassis earths, so there's some way to go yet!

Eddy

Eddy, yes, I think that is the direction I am leaning towards as well. I labeled the loom fairly well when I removed it from the donor. I will have to make sure that the labeling doesn't get "lost" while I am cleaning. I am obsessive about parts washing sometime and don't pay close attention to the labels. My 280Z into 250GTO conversion took longer because I washed away all the labeling... Won't do that again.

From what I remember about striping my loom out, the engine part is separate to the junk anyway. So for mid-engine as in our applications the loom should go back in pretty much as it came out.

I think!

Terry

Terry, I think you may be right about that.

I am wondering if some of the wiring from the interior loom is required to get the engine running?

In any case, I will definitely need to do a TON of splicing and lengthening to put things where I want them. The 4AGE isn't that complicated electrically compared to some other cars I have seen, but when you add the electrics and the vaccum lines together it becomes a rats nest.

Graber

quote:

---

Originally posted by sgraber

I will have to make sure that the labeling doesn't get "lost" while I am cleaning.

---

I plan on encasing the labels I wrote with clear packing tape. That way the writing will be visible, but untouchable by the solvents and cleaners.

Any other ideas on this? I think mine will be dandy

Real men don't need no frigging labels...



I guess that's why mine are labelled too...

I always intend to label everything, then forget when I get carried away ripping it all out.
It usually ends up in a carrier bag until you can't find one end from the other, then have to pull it apart in order to straighten it out!

Most of the engine loom connectors are colour coded and have different pin-outs so you can't connect them together except in the right places.

All you fellow 4AGE-users....are you plumbing in the hot water feed to the throttle body for cold-start idle-up, or not bothering?

Cheers,

Eddy

I intend to leave my engine as standard as I can. That means leaving on all heated manifolds etc.
Once car is built up and running I may start tinkering then.
I've made that mistake too many times before of messing about with the engine before finishing car. It usually ends up as a complete engine strip down and upgrade, that then has to sit and wait whilst I build the car around it. By the time I've done the car I've forgotten the details of engine changes!

I probably won't do any of the throttle body or other hoses other than those necessary to get the engine cool and ECU functioning properly. Of course, where I'm from freezing is a cold winter day and it's generally closer to 60F. In the summer it's regularly 95-100F so quick warmup isn't really an issue.

Bill J

Hi Eddy,

Nice to see you still about.

You will need to pipe up the cold start idle up, if you don't you will not get the revs down as it's spring biased.

It's this that provides the extra butterfly opening air when cold and enriched.
It performs the same type of function that a choke cable did.

Rob

Steve,

I used the engine loom part for my build.

You will find it's fairly easy to distinguish all the sensors as they should be colour coded together.

The loom is fairly straightforward to wire in and I mated it up to my existing Escort RWD loom easily.

The wiring colour codes were not repeated except for one which caught me out. The ignitor feed wire, this had the same colour code as the screenwasher pump feed!
I couldn't get the engine to start until I had sussed that one out. Using an oscilloscope finally to look for the ignitor pulses

There's an engine pic that shows loom fairly clearly on my site.

www.robs7.com

[Edited on 14/8/03 by Rob Lane]

Hi Rob,

Yes - I'm still around, and still haven't finished! I now have two deadlines to work to...1. SVA 2. baby due 2nd October!

The wiring diagram in the Haynes seems to show a vacuum switching valve connected to the fuel pressure regulator on the end of the fuel rail. Does yours have this VSV? I guess it could be used to keep the fuelling rich when you floor it, kind of like an accelerator pump in a carb. Aside from that, I thought that FPRs were connected directly to inlet vacuum, to keep fuel pressure at a value relative to inlet pressure.

Cheers,

Eddy

quote:

---

Originally posted by Rob Lane
Steve,I used the engine loom part for my build. You will find it's fairly easy to distinguish all the sensors as they should be colour coded together.
There's an engine pic that shows loom fairly clearly on my site.www.robs7.com[Edited on 14/8/03 by Rob Lane]

---

Eddy,

The water temp sensor feed to the ECU is used for other purposes via the ECU.

In this case the fuel pressure VSV is used to UP the pressure in fuel rail when engine is hot by altering the pressure regulator by switching vacuum on/off above diaphragm.

Normally the fuel rail is fed directly from pump and the return to the tank is via the regulator which 'bleeds off' excess pressure from rail. This can react quickly enough when all injectors call for full fuelling to keep pressure up.

Rob

Steve,

Glad you like the site. I set it up primarily to show the car and later developed it to give as much info as I could relevant to building a car.

There are other photos that are not on site if you need any other info, I can also take a picture of any relevant part you like.
I also have a rough sketch of the water pipe modifications I made to allow for rear of engine filling and removal of the thermostat housing/heater pipes.

Rob Lane