4agze build questions

[ae86boy]

I think the real difficulty comes from the air bypass in the throttle body itself. I guess its going to need to be plugged. I'm just going to toss it for now and go back to the tiny 4agze TB...at least I know it works.

[ae86boy]

Well, I got it running and took it out for "a spin" the other day.

Of course, a problem instantly developed. The heater core decided that this would be the perfect time to blow, spraying red hot coolant (green hot?) all over my interior which I had just replaced with like-new panels and carpet.

I can say that the car's temperature increased quickly upon driving it from cold...so the thermostat definitely warmed it up faster than normal. As for keeping temps lower...hard to say due to the problem. Once I get all the coolant out of the car I'll loop the line away from the core and run it without and see what happens.

[TERRA Operative]

A good way to get rid of the coolant is to hire one of those carpet cleaners from the local supermarket (Woolworths etc in Australia) and get the upholstery attachment.

Give the entire interior a going over while your at it, it'll feel like a new car.

[ae86boy]

Yup...that's a good way. I actually own a vacuum with a steam cleaning attachment.

I think I've gotten all the coolant out of the car...now I just have to get rid of the stuff that's dried into the carpet. Easiest way I know is to remove the carpet and then wash it out with a pressure washer. That's this weekend's project. I'll get that line looped and take the car out to blow it up again.

What do you think will break this time?!

[ae86boy]

So, I got it all together and took it out for a spin. For whatever reason the car has developed a hesitation from about 1/4 - 1/2 throttle...any thing less or more and its fine.

EIther way, the car still runs as hot as ever...I don't have exact temperature readings off the radiator...but it seems just as hot as before when it had no thermostat.

Thoughts?

[TERRA Operative]

Check the calibration of your TPS sensor, that may help the hesitation issue.

[ae86boy]

I'm going to check the TPS, the plugs and the AFM...I think its bad as well. The car is running wickedly rich (10:1 or so instead of 12:1 like it usually does).

Thanks again for all the help, I really appreciate it.

Any idea as to the temperature issue?

[ae86boy]

I took the car out for a spin and it ran well...no sputters or anything...quite quick in fact.

The thing it did was overheat again. It reached operating temp quite quickly and then just kept creeping up a bit at a time...while I was driving at highway speeds (100kph/62mph)...with no hood on the car...and finally when I got it home the radiator and motor were showing 110c/230f!

Am I nuts or is that high? Thermostat's at 88f.

I've heard theories like putting in a higher stat and knocking back timing...

any ideas guys?

[ae86boy]

I dialed the timing right off the motor, basically grabbed the dizzy and turned it as far retarded as possible...and it still overheated exactly as before...same amount of time, same road etc, but with an outside temp about 15c lower.

I'll try bleeding the system again today, but I'm not sure what else it could be? The only other thing I can think of is that I've changed the spark plugs, but I can't see how this huge overheat could be caused by a heat range or two...

[TERRA Operative]

Not the plugs, something is up with the cooling system.
Maybe the pump, thermostat, blockage etc. Could even be just a stuffed sensor.

Can you take some pictures of your cooling setup with the routing of hoses etc?

[JoJo]

From what i've read, I think you have the water system routing hooked up wrong..

Like Terra Operative said, post up a few pics of your water system setup.

The radiator you have, could even be considered an overkill, so I doubt that is your problem.

[ae86boy]

I think I've got it?

I took the car outside and ran it on the driveway...still overheating like crazy in seconds...and figured that maybe there was air in the system like I had said before.

I took the rad cap off and ran the car, noting there was no coolant flow in the rad at all. I revved it up to try and bleed it...still nothing. It was then that I noticed the lower radiator pipe was stone cold, but the radiator was red hot. I let the car cool down and rolled it inside.

The next day, I drained all the coolant out of the motor including the block drain. Once done, I took the lower radiator tube and flushed the rad with a garden hose...no restriction in flow was noticed...the water just poured out as fast as it went in.

So, reasoning that the lower rad hose could also be cold because the car couldn't pull the hot coolant *in*, I flushed it from the top of the motor down, jambing the hose into the upper neck and blasting away for a few minutes.

Apparently that's where the plug was. There was a noticeable restriction at the beginning and after a couple seconds the water just thundered out.

I have since run the car on the driveway for several minutes and the entire cooling system seems to run at the same temperature...it will stay cold enough at idle the electric fan doesn't even turn on at the minimum temperature setting.

Now, I haven't taken her for a spin yet, but I will later on today. I'm just praying that I have actually fixed the problem and that whatever was plugging the block came out and isn't just hanging around waiting to screw everything up at the worst possible time.

Thanks again to everyone for their help, I really do appreciate it!

[allencr]

There was a noticeable restriction at the beginning and after a couple seconds the water just thundered out.

Missing any shop rags or duct tape that was covering the coolant ports?

[TERRA Operative]

Common problem with intercoolers too.....

[nick.parker]

So, I got it all together and took it out for a spin. For whatever reason the car has developed a hesitation from about 1/4 - 1/2 throttle...

Hesitation is often from lean misfire, especially on 'tip in' when you are moving the throttle towards the 'floor'. However if your plugs are black then its probably over fuelling - lots of dark grey smoke out the back? AFM 4AGZEs have a reasonably well known issue (too lean at lows revs and more boost than stock) which leads to less torque than you could have. Maybe the extreme end of this is lean misfire. My 5c is get/borrow a lambda meter to help diagnose what it is or isnt. I have wide band permanetly in my exhaust and 'tune' my own car and it works brilliant - well good enough for me.
I have an electric water pump which I run from my ECU. Tried not having a thermostat. Its no go. I couldn't regulate the block temperature just by varying the pump speed. On cold nights at cruise coolant would drop to 50 degs etc...no good!!!! Slowing the pump down is not (disclaimer - IMHO) a good solution as when you gun it you'd probably generate a temperature differential across the block.
So I put a remote 77deg thermostat in... logging the engine temp it almost never varies from 77 after initial warm up. rant over.. (well except for hot days where it runs a bit hotter, as t-stat wide open and radiator being what it is etc).

Oh yeah , last thing, I imagine overheating coolant is a bad airlock or a 'failing' head gasket. I have same problem. About to hopefully solve with studs and metal gasket also....

Cheers, Nick.