Hey all!

My nearly 1 month of work on the 87 iroc came to an end today. I did a whole bunch of mods while I had the time and tools to do it. Mods, in no particular order were: upgraded stock Blaster Coil to MSD Dual Blaster Coil, TB coolant bypass, Fel-pro intake manifold gasket kit, 180* JET thermostat, gutted airbox, ported & polished the plenum, removed air pump, removed ac components, cleaned up the engine bay a bit.

Seeing as how this was my first time ever working this extensively or in-depth on my engine, I was pretty nervous I got everything right putting her back together. Stuff like if I did a good job on the RTV sealant on the china walls still haunts me. Who knows where I'll be when my rtv job decides to take a dump? Also when I took the distributor out, I did mark the location of the rotor on the housing, but I wasn't sure if I put it back in exactly right. I heard that with computer controlled cars, the timing can be adjusted to some degree (no pun intended), but it must be close. Was it close enough??

Arriving at the moment of truth... I turned the key for the very first time in a month, and... turns over but doesn't start. Dang! What did I do wrong??? But I wasn't about to give up on the first turn of the key (you know our old cars). So I turned her over again, this time giving her gas as well, and she STARTS RIGHT UP!!!!

Oh man I can't tell you how happy I was to hear the roar of her rearend again. It took a while for the computer to relearn stuff, but after 15-20 minutes she was purring like a very satisfied cat.

Only a few minor problems remain, such as I think I unplugged the temperature sending unit (to the gauge) while I was removing the ac bracket. Oh well, I dropped her off at my mechanic cause he's gotta do some body work + paint, but I'm also gunna have him go over everything I did and we'll have a good talk.

I hope this encourages anyone who is thinking about getting to know their engine to do so! The only way you'll learn about it is to do the work yourself. Anyone can do it, you just need to be patient and willing to mark down everything. In short, use all the resources you can! I have Chilton's, Haynes, thirdgen.org, my mechanic, and various other resources to ensure I do the job right the first time. And it sure looks like I did!

 

Great job man! Congrats!

I would recheck the timing even though you think you lined it up right. Its not that hard to do. I installed my new msd dist and it sounded fine too. When I checked it I discovered it was off.

 

Thanks! It was amazing that she fired up at all, considering this was my very first time! Cherry popped, I'm now ready to move on.

I'll have my mechanic do the timing tho. I don't have a timing light and would prefer he look at it and describe it to me.

After talking to my mechanic today, he sort of frowned at the throttle body coolant bypass mod when I told him about it. He said if it's cold out and you're decelerating, watch out. That kind of thing has me worried, because he knows his ****.

 

In Maine I'd consider it. Around here in Arizona it's not an issue at all. I don't think I see many aftermarket throttle bodies with coolant lines either.

 

I agree...I am trying to figure out why the mechanic said to watch out. Oh well, its late...PS: my mechanic has been racing cars in the qtr mile for over 20 years and is a good friend of mine. He built my 406. He knows his stuff, but he is also fallible. There are things I have learned about my car that he didnt even know. He is a carb guy and when someone has questions about FI he sends them to me.

 

I believe he said watch out because if it's cold out, and you're decelerating, and the tb becomes stuck, it won't be able to slow down the engine. The computer senses the extra air, adds extra fuel, and the engine rpms stay high. At least that is what I assume he statement means.

It is summer time here. Do you think I should go ahead and put the tb back to stock condition, or just wait until winter? By the way, I go to school in NY so I'll be there for winter actually.

 

I have never heard of that happening. Why would the tb blades stick open? I would leave it for now and change it later if you need to but now that you explained the reason he gave you i wouldnt even worry about it. Just my .02$

 

I'd think that the ambiant temperature that the engine bay gets to wit hthe motor running would be enough to keep it from sticking. I know that the TB get's hotter than a **** with the coolant hooked up, but even after removing it it still gets warm to the touch, and if it's warm to the touch it is warm enough to not have contracted the metal enough to make the blades stick.

 

The thing to be concerned about with the coolant lines disconnected is throttle body & throttle plate icing during cold weather. I've never seen it personally, but it is a concern in colder climates.

-B

 

Nevertheless, as mentioned, if the throttle body is warm to the touch during normal engine operation, even with the coolant bypassed, there will not be any icing problem. Also, if you are concerned about the blades icing while the engine is off, the coolant isn't going to do much for quite a while anyways since the coolant will be just as cold until the engine warms up a bit. All the coolant in the TB would do is accelerate the de-icing, but probably not by too much. I would think the engine bay would heat up just as quickly and warm up the TB enough. Its not going to help you if they are frozen shut anyways because how is the car going to start to get the coolant moving if the blades are iced closed anyways..

Actually, this was the first time I realized that this mod is healthy to do in most climates. I was debating doing it because our Chicago winters, but now that I've thought about it and what I've just posted, I'm not worried about the mod at all.

 

I wouldn't bet the farm on it. The icing that the coolant flow through the tb is supposed to address is not necessarily due to ambient temperature, but due rather to the venturi effect of air flowing through the throttle body at operating velocities. Even an intake that's warm to the touch can develop sub-freezing temperatures internally in the area of the throttle plates under certain conditions.

-Bob