Fast Idle Solenoid Switch... Where Is It? 1984 6.2 Suburban K2500

[CORVAIRWILD]

My '84 6.2 K20 Sub won't drop from fast idle. So 5 years ago, I disconnected the solenoid. I've just chngd the water pump, so now's a good time to put in a new switch. But what is it called/part number?

I looked around, and almost found what I think I need...

http://www.gm-diesel.com/vbull/non-.../22051-6-2-cold-start-solenoid-fast-idle.html

The one behind the RH ex manifold has 2 prongs, and I think that's the correct one. Maybe I'm also running cold advance all the time if the fast idle won't drop by itself? The sol de-energizes when I pull the green wire.

 

[WarWagon]

Cold advance and fast idle are tied together, yes. From the post it looks like the switch may be for glow plugs only. I would look at the rear head coolant block off plate. I recall my 86 6.2 had some sensor in it I pulled out for the 93 swap. Is the old style glow plug controller screwed into one of those plates as well?

If in doubt unplug it and see if the wire for fast idle loses 12v.

 

[CORVAIRWILD]

I've never looked closely, but the green wire also goes to the side of the IP for the cold advance, then goes directly to the fast solenoid. I'll call the dealer for the availability. It is the switch behind the RH ex manifold

 

[just a number]

the switch is called a inhibit switch. it controls fast idle, cold advance and the glow plugs. the thread you linked to is correct. it sounds like yours is stuck in the closed(cold) position. confirm it by either a 12v on both sides when hot or a continuity/resistance test.

 

[CORVAIRWILD]

After 30 minutes poking around, I finally found the part number no, and my local dealer has to order it, for $47 my cost, and Amazon has it for $19 free SH. Go figure...

This's copyed from their text... "Fitment Notes: FI PUMP COLD ADV SOL ENG COOL TEMP - 2 PRONG - 3/8-18" "ACDelco 10154649 Switch Assembly"

I'll open the abbreviated words for future searches. 6.2 Diesel Fuel Injection Cold Advance Solenoid Engine Coolant Temperature Sensor Fast Idle

http://www.amazon.com/dp/B000C9D1SW/?tag=jhuntlink-20

http://www.amazon.com/gp/product/handle-buy-box/ref=dp_start-bbf_1_glance

 

[BBB82]

Ya there are Two temp switchs, ONE temp read. There should be one in your cross over up front to the left of your IP that controls your cold avance, the one in the DS rear head control the GP, and last the one on the lower DS block works the temp gauge on the dash.Thats how mine is wired and its stock.

 

[CORVAIRWILD]

Yup, I ordered the switch from Amazon, $18 shipped, and $42 from local GM dealer after discount. It should arrive today..

Oh, and why would you only run a single tstat w the fancey engine you built?

 

[BBB82]

After reading how alot of peolpe have singles and say its just as good, I wasnt about to fight with it again to take it apart for dual plus a wasnt able to mod the throttle bracket at that time. Also with the dual 16" fans and all aluminum radiator I felt I didnt require it.

 

[CORVAIRWILD]

Yeah, I think it's a fair amount of work with the mechanical pump, some of mine have electronic inj. Is there a hi flo tstat (for the single)? I have a '93, and an extra dual tstat crossover...

which dual fan set up do you have? How much? And only a dual core rad? Hmmm... I'm putting in a 4 tube extra cool, from China as we speak... cost $325 I think, DELCO wp, China too!

And what's special on a '98 backing plate?

http://www.youtube.com/watch?v=VL_KVUQFJys

 

[BBB82]

Yeah, I think it's a fair amount of work with the mechanical pump, some of mine have electronic inj. Is there a hi flo tstat (for the single)? I have a '93, and an extra dual tstat crossover...

which dual fan set up do you have? How much? And only a dual core rad? Hmmm... I'm putting in a 4 tube extra cool, from China as we speak... cost $325 I think, DELCO wp, China too!

And what's special on a '98 backing plate?

http://www.youtube.com/watch?v=VL_KVUQFJys

Special plate no but if you want a Sep BELT setup you have to change it, so mine was ordered for a 98 so I could also install the HO water pump, along with a 98 oil tube, gourmet, cap. The Griffin aluminum radiator was from Summit Racing along with the 16" fans I paid like 600 for the radiator. I hear alot of the new ones are aluminum with plastic ends glued togeather, so I just went with a racing one.

 

[WarWagon]

You 100% sure you only need 1 switch? I had the GP switch stick on my 1988 and she ate the blown in half glow plugs. Everyone is describing 2 separate switches. However, the glow plug systems changed over the years. If you have self limiting glow plugs they are slower to heat up but won't overheat and fail.

4 tube extra cool? Would be helpful if you guys posted up part numbers or where you are getting them so others could see what you are talking about.

 

[just a number]

the are 2 switches. one just controls the gauge, it's in the ds head near the front. the rear one is the fast idle, cold start advance.

I feel your pain about the controller sticking. Mine did the same thing with a brand new set of plugs.needless to say the manual setup went in a few days later.

 

[CORVAIRWILD]

I will post pix of the cold adv switch, and the radiator, which after it arrvd, I saw that it was fr China. The glow plugs in this '84 Sub, (the one in the vid, I have a few) work perfectly. I've never touched anything.

My other K5 Blazer, also '84 and 6.2 has messed up wiring, but the fast idle works fine, and presumably the cold advance. I'm not sure about the extra rattle when cold cause old engines all rattle I suppose. The Sub has 270k, always frequent oil changes, it must have someone's baby, and the K5 has 135, runs sweet, but crappy maintenance, and it was a neglected/abused wreck when I bought it. I'll do a cold start video on both today, after I install the new switch in the Sub.

I also wish I woulda' had the foresight to install a flat belt system in the '84, the V belts are always getting loose/stretched and squealing. The flat belt/self tensioning is THE BEST!

 

[just a number]

the v-belt system works fine. just use the gates brand belts. I know they're also marketed under the NAPA gold line(same belt) the big problem is that a lot of the replacements are a hair skinnier and don't fit into the pulleys right. I found the alternator belt was the worse.

ok back on topic now.

 

[BBB82]

Heres my aluminum one Im running:

http://www.summitracing.com/parts/gri-6-576ar-bax/overview/year/1982/make/chevrolet/model/k5-blazer

I see the price has gone up a little.

 

[CORVAIRWILD]

I've used every kind of V belt, $4 ones that are too wide, top cog, green line, Goodyear, Kelly Springfield, Delco etc. None last, they all stretch and squeal. Truck is BONE STOCK! Old switch is out, new one will go in as soon as I warm up, heat's off in shop

 

[just a number]

how long are the belts lasting before you have issues?

heated shop??? I've never heard of such a thing:hihi:. I get the great outdoors to work in. now I'm jealous.

 

[CORVAIRWILD]

Belts? they last under 10,000 miles, 16,000 kms