Author Topic: C4 1987 Throttle Body Coolant Bypass (Read 26101 times)

Vettech · « **on:** July 31, 2020, 08:57:33 PM »

Well since I have half the engine ripped apart and a friend mentions bypassing the Throttle Body's (TB) Coolant and I'm locked down in Covid19 seclusion, the mind wanders into Google and Youtubes. After much reading, it is obvious that the heated TB is good for freezing conditions in the northern hemisphere, stops the TB & its butterfly valves icing up and freezing. Whilst I'm keen on skiing and have several sets of snow chains, I dont think there is any way known to man to get those chains around the rear tyres into the guards without causing major damage to the tubs. Why do I mention this, well, I dont really do mods for mods sake.
BUT !.
Since the 87 is apart, and I can clearly see the high levels of corrosion associated with the cooling system, and I' m trying to get the water, heater and pipes/hoses back to a concise clean layout, and a hot TB is not really required, then its time for a mod, which should allow a better hose layout etc. My87 is a Mirror Conversion, thus heater is now on LH side, along with the Oil Cooler, which started this sorry saga originaly, whilst most of the original pipes/hoses, hot water valve have been junked by the converters. Today driving home In the 90, I was cold, turned on the heater - dialed up a nice level of toasty warm (I must be getting old), I was nearly talked out of repairing the 87's Heater Matrix, after today I'm glad I stuck to my guns and I'll be attacking the 87 with renewed gusto.

I'll have to get a camera that takes pics that can go onto this forum.
Regards.

MY081 · « **Reply #1 on:** August 01, 2020, 04:58:06 PM »

Photo's on this forum (never happen ) Say Christmas in July !!!! Or Sunday lunch to Jamberoo !!! Bondi Breakfast !! Just saying Ray

Vettech · « **Reply #2 on:** August 01, 2020, 06:47:13 PM »

Thanks Raymond!.

We did have issues like the file size, this was modified by PeterP and upped to 900kbit.

The issue I now have is my ipad went kaput - they raced off to buy me a new one (they must think I'll include them in my will - lol)

The new one (same brand etc etc) but the file size is even greater and it gives new file types, where we only accept certain types.

Having said all that - I do remember you being at xmas in July, what pics did you take, where are they etc etc etc.....

Well ?......

Vettech · « **Reply #3 on:** August 01, 2020, 06:51:38 PM »

Now back on track...... thanks for the call Sirfixalot.

But sitting here now, do I remember correctly, you saying reverse flow.

I thought the LT1 was reverse flow - BUT does that apply to the std L98 ?...

My apologies, the below pic we had trouble with, and my daughters fingers are so quick it went in here, anyway it shows much mess and corrosion, note the IAC body, you cant see the Pintel for the black crud layer.

MY081 · « **Reply #4 on:** August 02, 2020, 03:12:08 PM »

ME post photo's on any Forum would be a miracle !!! but wear have all the members gone who used to post photo's here. It's not your responsibility or anybody else's to post photo's . Members used to do it just for fun !!!!!! Ray

Vettech · « **Reply #5 on:** August 02, 2020, 03:42:36 PM »

Time and Tide Raymond.

If you look down the bottom of the forum page you will see two (2) Users, and 59 guests.

Those 2 users are you and I. Whilst the 59 could be anyone from any place world wide.
And they could be just as easily 59 club members. Not all members come on board and even those who do may only ever look & read.
I'm surprised how many club members I talk to say "yes I read your post - it was good/bad/indifferent) but they never go as far as to comment directly onto the forum - whilst some do get involved and voice their opinions - they are the ones I like best, because they can throw another perspective on an issue.

And your not the only one with limited computer skills, I now, only ever type a sentence or two, because in the past I've typed up an A4 page of technical guff only for my thumb to hit the wrong something and I lose the lot, so I post a sentence then do a "modify" and thus build up the text.
Past issues with heated arguments are no longer an issue, but may have put people off.

I'm happy if I see those numbers like todays at 50 ~ 60 which means we have Corvette Interested people on line. The next time I see you I'll show you how to post up a pic - its not like the ole days with a photo bucket ??? Thingy, as long as your phone takes a pic with the correct acceptable format ie jpeg, etc and under 900kbit it should post up easily.

Regards.

Vettech · « **Reply #6 on:** August 02, 2020, 04:13:54 PM »

NOW BACK ON SUBJECT.

Sirfixalot - I removed the TB, the manifold side is like the bottom of a coal mine, the water galleries are a mess, the vac ports are full of crap, the pintel on the IAC is an unrecognizable blob of black crud. I thinks the whole assembly is way past a service. Also the seven screws were all different, ones head came off, they are all a rusted mess.

Did you get gasket sets or ??? I'd imagine that place at Eastern Creek would have them, cant remember their name, but surely these are fitted to Holden vehicles. ? I took some pics (with phone) I'll try to post them. (Was Rocket Ind - nothing in Cat)
See! Who said the Pres was good for nuttin. I sent my pic, he returned in different format and smaller size.
Of course no one has been in this TB before, umm of the seven (7) IAC body screws, three were longer Phillips with a drilled out nut as a spacer, three came out correct, whilst one had only the head left.

sirfixalot · « **Reply #7 on:** August 02, 2020, 07:25:34 PM »

Glen from Corvette Corner in Victoria has the complete gasket set. I didn't replace the bottom gasket as I am disconnecting water heating.Top gasket under TPI was non existant so there was a potential vacuum leak, Idle control valve washer was non existent sealed with silicon. I bought main gasket from Ponti world same price Glen has complete gasket set.made a new top gasket & a fibre washer from repco 3/4 " hole. Discovered a new problem where the hose tail comes out of front of manifold it goes straight into a bracket for air pump valve have to source a half inch BSP 45 degree male / female elbow. Also need to source small spring clip which holds auto kick down cable onto throttle shaft

Vettech · « **Reply #8 on:** August 02, 2020, 07:59:11 PM »

Ask Bob, I know the ones you mean, I only removed them this arvo.
Else Phill in Vict or one of those walk around get you own wreckers.

sirfixalot · « **Reply #9 on:** August 03, 2020, 06:59:30 PM »

Your throttle body looks worse than mine but you will be surprise what a scratch brush & some turps will do I have a couple of small round nylon pipe cleaner type brushes pushed in every where then flushed with hose.

Vettech · « **Reply #10 on:** August 03, 2020, 07:30:33 PM »

Ummm I'm thinking that on Wednesday I'm home alone, and the dishwasher is empty. Aha she has gone Tues .....

Well it came up a treat, went to Konnect at W'pk got 7 x (M4 x 0.07) x20mm 316 S/S cap heads.
Decided to cut the complete water tails off flush. I wont run water thru it.
Ran M4 tap down the hole threads to clean them out.
Now to get the broken screw out...... ummmm.

Vettech · « **Reply #11 on:** August 12, 2020, 05:05:25 PM »

Well no 0ne has the Gasket Set except Glenn at Corvette Corner . Vic. Ordered.

Fixed the IAC connector - pluged in, new battery, couple hrs of charging, power up and IAC runs the Pintel out of the port.
Turned off power and nothing - I thought these run the Pintel back into the port upon switch off..........any one ????

Vettech · « **Reply #12 on:** August 14, 2020, 02:01:23 PM »

Still waiting on TB gaskets. So I'll clean up the front on engine ready for bits to bolt on, check out old Water Pump, umm still one of those Stud/bolts in it, even though there are no threads inside the actual pump housing, its as though its threaded down tight.
Eventually, penotrene, largish hammer it came out, a ring of corrosion was all it took to hang on like grim death.

Now they look different, there is no heater spigot/tail in the new pump, the old one is also well and truely corroded in, plus I have no tool that size or depth to get it out - time to source a new one. I do have an enormous shifter, but where, bugger it, just get a new one.

Now - after going to PEP's, getting this bit may not be easy. They had a short tail, but the hex was on the thread's so its impossible to get it tightened down, now what did Sirfixalot do on his...... ummmm.

Vettech · « **Reply #13 on:** August 19, 2020, 02:15:13 PM »

The tail out of the front of the manifold which carries water out of manifold thru a short horse shoe bend hose up into the TB housing, thru housing and out the RH side, well that tail is RS totally, after nearly two weeks of getting the correct tools, giving it applications of Heat and Ice water, penotrene, 3ft bar, it finally gave up and came out, but only after I used a Lump Hammer.

If any one out there wants a new "U bend hose", also you can have the original funny looking OEM hose clamps. If you want original stuff on your car then you are welcome to them. Let me know.

Now to get a new tail fitting, and run a BSP tap thru the hole. It really was amazing how tight this fitting was in the manifold, I suppose having a type of steel screwed into aluminium, submerged in water for 30 years will give cause for concern, its little wonder why mechanics refuse to work on cars of this age, to us its a simple job and we get miffed when charged extra for broken, decrepid stuff we thought was ok.

Vettech · « **Reply #14 on:** October 22, 2020, 08:25:36 PM »

This TB BYPASS has wanded right thru the car. So far we have done the following:
1. Replaced the water pump. (Leaky & noisy)
2. Replaced heater matrix. This included repairing fire wall holes and heater A/C housing, pulling LH dash out.
3. Modified the TB by removing the inlet/outlet tails ( no more water thru the TB). Fit new gaskets, screws etc
4. Replaced the front manifold water oulet with a 90* fitting with a smaller 8mm tail sweated in, to allow pickup of the steam vent.
5. Removed, cleaned & painted all the carriers/frames on front of engine.
6. New hose from manifold rear steam vent to front pickup.
7. Re-installed the metal "KC4" line from KC4 up to water pump.
8. Repaired KC4 water tails, re-installed along with new Oil Filter (also cleaned rust out of block at KC4 port)
9. Fit new hoses etc to KC4.
10. Remove A.I.R pump and modify accordingly.
11. Fit new "T" piece, hoses etc where KC4 meets water pump side return and heater return.
12. Obtain "02" V8 Comodore (heater to heater tap) hoses, allowes heater to connect down past frame, turn forward.........
And:
Thats as far as I've gotten, I intend to use GOSS 16mm ID heater hose to connect from "T" piece thru heater then to 90* fitting, also I hope to bend up some 5/8 Annealed Cu pipe to connect the hoses, but at the moment I've not allowed for a heater water tap, but the 5/8 pipe should allow its retro fitting at a later date, but since my 90 has no tap on it, I may in the future depending on how well the 87's A/C works opt for no tap ..... we will see.

And for those who are asking "why is he using 5/8 Cu pipe", well the original "conversion" left a lot tobe desired, all hoses THEY ran had 90* kinks in them, thus blocking flow and promoting corrosion, also one ran right under the engine very close to manifolds, cooking very nicely. The Cu pipe once bent to shape is a smaller cross section than the hoses, can be bent to fit into the tight spaces past the LH manifold and up to and under the Alt and A.I.R pump to pick up the new brass 90* fitting, should look neat and tidy and out of sight.

Now waiting on a 5/8" pipe bender - and yes I know all about sand and springs and things, but I'm getting more decrepid by the week and my hands no longer have the strength of old and besides its another nice tool to hang on the wall, you can never have too many tools.

Vettech · « **Reply #15 on:** October 23, 2020, 03:23:03 PM »

Well it looks like I waited all day for the Bender - maybe Monday.

Also was waiting for a new antenna Diplexer, but allas no TV till most likely Tuesday.

I cant watch Foxtel in the Queens room, that leaves Netflix, Stan or Bob or something, all old rubbish.

I wonder if there something else on the car needs fixing ?!?!...

Vettech · « **Reply #16 on:** October 30, 2020, 05:57:02 PM »

Well today I visited the "Oracle @ the Wilton Black Hole"

Its amazing how you can see a fix but another person see's a different fix.

After discussions, other ideas supporting ways to fix my heater hosing, routes, tubes etc appeared.

Maybe over the weekend I'll be able to put the Oracle's ideas to use.

Also was thinking of a new project for the Oracle, converting a 5/8" bender into a 1/2" bender....... ummmm.

Vettech · « **Reply #17 on:** November 16, 2020, 07:30:27 PM »

Well its all back together except for the upper Alternator bracket - had one organised but it fell threw. Searching

Oil is in, no leaks. Water is in, no leaks, yes water for now - as I intend to give it a couple of fill, run, flush cycles. Maybe try the crushed dish washer tablet cycle I saw on a UK web site.

No AC at this point, I have a new Accumulator (VB Comodore SLE) type, why, because it has reversed fittings and since I need to get some new hose/pipe sections made to accomodate the Left/right conversion, the hoses etc will be direct straight forward (easy) making the setup neat & clean, and of course it will he "High Chill -30" type refrigerant.

A tip - used or second hand aluminium A/C hose fittings can be re-used - carefully cut the crimp off, it can be refitted with new ferrel crimp, onto new A/C hoses. Or if you get onto a good AC chappie, he could make new Alli pipes to measure, these are neat and tidy and more compact than the much larger Rubber style hoses. (I saw a late nite show - a guy in Qld making AC lines, bending etc and welding, which I think is more of a Silver type solder, good looking job though).

The cars so ready I decided to kick her over on Friday, but no start, no fuel, cant hear pump running, now I just want to burn it, what next can possibly go wrong.

Vettech · « **Reply #18 on:** November 18, 2020, 02:18:03 PM »

Well the fuel pump cct is a bit convoluted, and goes from engine (relay) back thru firewall thru an array of connectors before heading off to the pump in the tank. (Keep in mind that on C4's once started the fuel pumps power is supplied by the Oil Press Switch as a fail safe in the event of loss of engine oil pressure.)

Found Relay - it fell apart in my hands, after a clean and test lamp & metre on the bench even as a mess it worked. Thank God for Silastic and black cable ties.
Wires go back into car thru a 15way interconnect ..... which because the dash is still apart was disconnected, re-plugged, hit the key and I got wonderfull smell of fresh petroleum in the morning. Re-fit fuel lines, pressurized the rail and she burst into life. OMG it goes.

Now to get that Alt top bracket, AIR pulley on, belt on, then off to get a pink slip for Rego (MOT), may even put it on H'plates after all it is 30 odd years old. I should be running on double plus ++ H'plates

Vettech · « **Reply #19 on:** December 12, 2020, 10:30:15 AM »

Small update.
As of today the engine is all back together, starts, runs but now needs TPS adjusted.
It amazing how many tiny specs of grease or oil you can drip onto manifolds etc, anyway after the smoke cleared it ran well.
Whilst the A/C comp is on, it needs to come off very soon for a rebuild, new hoses/lines made to order, gassed with HiChill -30 and she's a fully working rocket sled. The most important thing now is the due pink slip, thence maybe onto H Plates.
What started as a blown heater matrix has led to a massive overhaul of many and varied parts and systems.
Some repairs were required after trying to get other faulty parts out, these in some cases just crumbled in your hands its no wonder that a lot of mechanics won't touch old cars, owners quite often can not understand the extra parts and labour costs.