My 1992 Gmc Typhoon

So ever since i can remember ive always wanted a Typhoon, i rember growing up and one of my teachers had one and i thought it was just the coolest car ever. However as life goes on you get other project cars and kinda just go with the flow and forget about your dream cars. Well a few weeks ago my dad tells me, hey my friend has a typhoon that hasnt moved since 2006 and is looking to sell it. I had been looking at a few mercedes wagons to buy and when this popped up i jumped on it. This car is a survivor for sure with 159,000 unmodified miles, its been under a car cover in a dry garage since it was parked. It needs basically all the suspension bushings and just to be gone through. So i used his hoist to drain the fuel from the tank, i had tried to power the pump up and got nothing, so go figure it had a dead pump. Ran and got a delphi pump and drained the varnished fuel from the system and installed the new pump. I threw some unleaded sunoco 104 in the tank and took the valve out of the fuel rail and flushed the rail out. I also changed the oil and installed a new battery. All the fluids had been changed prior to being parked which was nice. I had no fuel smell in the oil at all and no condensation either. I turned the key and the thing fired right up just like it had been running the day before! I threw some air in the old tires and let it get up to temp and drove it 30 miles home with 0 issues. When i first started driving it there was quite a bit of blue smoke out the exhaust for about the first 3 miles, mostly when pulling away from a stop, im figuring som oil has leaked past the valve stem and turbo seals from being parked for so long. By the time i got home there was 0 smoke and it was idling very very nicely. So im going to be going through the car and cataloging my adventure here. there is surface rust on the frame but nothing concerning, im going to go through and clean and coat as much as i can within reason. plan is to get the air suspension working again as it has been disconnected. but even the cruise control works on this thing!

gD0WZp0.jpg


pZGKh6k.jpg


yEBg1vo.jpg


and back home

X9uNVDx.jpg


i removed the wheels to get the tires pulled off and get them redone, they had been chrome plated and all of that was flaking off so they look ratty. luckily there was a set of zr1 wheels sitting around so i threw them on as rollers for now so i can get the stock wheels redone.

EL5uhYm.jpg


the lower intercooler radiator was leaking pretty bad from the center core so i contacted sportmachines and have a replacement lined up from them. im trying to keep it as original as possible.

8LqgnIs.jpg


the upper ic brick had a bad over flow nipple so that was fixed as well and i reinstalled it

PDLbklp.jpg


thats all i have as of now, just placed a big order to redo all the suspension on the car and get it driving good. Ill update when more developments happen!
 
Definitely a nice looking truck. Welcome to the site, some very knowledgeable owners here and they have pointed me in the right direction a few times. The biggest problem I have had so far is finding some of the obscure and specific parts to these trucks. Funny, was just going to have my engine rebuilt due to bad #3 rod. Ended up dismantling to the frame for full rebuild/restoration along with replacing most of the engine internals. Due to lack of space, my truck #0229 spent a few years outside in the backyard, although mine only has 66K on the clock, was not as nice as yours when I started. Good luck with yours. Look forward to seeing pictures of your progress.
 
Ill see if i can copy paste what i got i went with loaded upper and lower control arms and as much ac delco parts as possible. I did the plugs, wires, cap and rotor as well as a new coil. the car had a rough idle and when i had the ic brick off i was chasing the misfire. i narrowed it down to cylinder number 4 as i unplugged the injector and nothing changed. i did the brake clean vacuum leak test and found a ton of compromised vacuum lines. I replaced all the lines and still had the misfire on number 4 so i pulled the fuel rail off and sent the injectors out to Eric Derr to get tested and cleaned. they ended up being perfect still but he put new filters, o rings and pintle caps on all of them. i reinstalled the fuel rail and injectors and still had the number four misfire. upon closer inspection i found that the intake gasket was blown out on number 4.

UeAhS1W.jpg


initially i missed this but im glad i found it. i went ahead and pulled the intake and power washed it and cleaned up the heads and re assembled it.

23BGZmA.jpg


8frOpCg.jpg


B69pDrk.jpg


even though im trying to keep the car as stock as possible i decided those intercooler metal lines have to go. upon putting the car back together i put the distributor back exactly where it went. i looked and found a old icm in the trunk so i am assuming its been replaced. so i got the car back together and it started great. no leaks and it was running well. but now instead of a misfire i had a idle surge. i rechecked and found no vacuum leaks. i reset the idle air motor through the diagnostic port and still it wasnt very smooth. i went ahead and disconnected the brown wire to check timing and couldnt find the timing mark on the balancer. i pulled the number 1 spark plug and found tdc compression on number one and checked and sure enough the balancer has spun a little bit. i remarked the balancer and checked the distributor and got it lined up with number 1 and started it. with the brown wire disconnected and timing at 0 on the pointer it runs absolutely perfect. when i plug that back in it started idle hunting a little bit again. i went and drove the car and it had plenty of power and no audible detonation (probably some of the race fuel in the tank is helping that). i checked timing again and i read these command around 22 degrees at idle? it is jumping back and forth a little bit so i went ahead and ordered a ac delco distributor with new icm and pickup.
 
Definitely a nice looking truck. Welcome to the site, some very knowledgeable owners here and they have pointed me in the right direction a few times. The biggest problem I have had so far is finding some of the obscure and specific parts to these trucks. Funny, was just going to have my engine rebuilt due to bad #3 rod. Ended up dismantling to the frame for full rebuild/restoration along with replacing most of the engine internals. Due to lack of space, my truck #0229 spent a few years outside in the backyard, although mine only has 66K on the clock, was not as nice as yours when I started. Good luck with yours. Look forward to seeing pictures of your progress.
Thanks! these are cool cars for sure, but man they are so archaic in design! I have pretty much only owned european cars and a few ls swapped cars and this is like jumping into uncharted territory, have to go back to caveman mentality working on it! haha
 

DaveP's Ghost

Active member
When you reported the blown intake gasket, I was thinking "and the balancer is probably spun too. He'll have trouble getting the timing right after the manifold is back on..." And sure enough, you had the spun balancer.

Replace the balancer. Because it is sheared, it can't do its job to dampen harmonic vibrations on the crank.

These cars will test your patience and diagnostic ability. I've owned 7, and worked on dozens of them. Try to resist the temptation to "put a chip in it". PARTICULARLY a Turbo Tweak. The ongoing mysteries, problems, and stuff that doesn't make sense that TT chips cause isn't worth the aggravation. Just say no.

If it made it to 159k and still has its original engine, it probably still has the stock calibration in it, and that's the reason why it has lived so long. My Ty has a lot of miles too, I've owned it 25 years, the valve covers were last off 20+ years ago to do the stem seals, the engine has never been out from between the fenders. I just put its 4th heater core in it, but that's a different deal. Engines cost a lot more than heater cores.

Good luck with your Ty. Keep it stock. It will continue to serve its new owner well like it did its previous one.
 
Last edited:
When you reported the blown intake gasket, I was thinking "and the balancer is probably spun too. He'll have trouble getting the timing right after the manifold is back on..." And sure enough, you had the spun balancer.

Replace the balancer. Because it is sheared, it can't do its job to dampen harmonic vibrations on the crank.

These cars will test your patience and diagnostic ability. I've owned 7, and worked on dozens of them. Try to resist the temptation to "put a chip in it". PARTICULARLY a Turbo Tweak. The ongoing mysteries, problems, and stuff that doesn't make sense that TT chips cause isn't worth the aggravation. Just say no.

If it made it to 159k and still has its original engine, it may still have the stock calibration in it. and that's the reason why it has lived so long. My Ty has more miles than yours, I've owned it 25 years, the valve covers were off once to do the stem seals, the engine has never been out from between the fenders. I just put its 4th heater core in it, but that's a different deal.

Good luck with your Ty. Keep it stock. It will continue to serve its owner well.
yea this thing is going to remain stock. i am looking at balancers right now for it and due to all of the steering components needing replacement i may as well do that while i have the lower ic out. is there any brand recommended? I cant find a oem replacement as of now but it is on the list for sure.
 

DaveP's Ghost

Active member
I've been using Dormans. $45 and I get them the same afternoon. I don't know how durable they are. The one on my 93 is about 5 years old, when I'm doing other things and can get my hands on it (literally) I try to twist the ring. So far, its still snug.
 
I've been using Dormans. $45 and I get them the same afternoon. I don't know how durable they are. The one on my 93 is about 5 years old, when I'm doing other things and can get my hands on it (literally) I try to twist the ring. So far, its still snug.
awesome! thanks for the input i just added a dorman to my rockauto order!
 
Well I had a bit of a fun week with the typhoon.... I started the week with ordering a reman ac Delco distributor for it. I have been a technician for over a decade and have come to realize most of the time you want the OEM parts. That being said I went with my gut and got the ac Delco distributor. I would imagine that being a ac Delco part it would be good quality. But I was sorely mistaken. After installing the distributor the car ran better then it ever has. I went out and drove it and gave it a bit of a mid/hard throttle pull and it just flat out died. Went to crank it and no tach signal on the dash, great. So I popped the hood and looked around. All my connections were good, luckily I always carry tools with me. I pulled the cap off and the icm was boiling hot. I grabbed the brake clean out of the tool bag and hosed the icm down and cranked it over without the cap and like magic the crank signal was back. I reinstalled the cap and limped the car home. I immediately went to the local parts store and grabbed a new distributor which was a cardone unit. Threw it in and the car fired right up and ran like a new car. No hunting idle, timing was perfectly stable, and the car feels alot better now. I got a icm from the dealership which is going in the glove box but as of now it runs great. I have a video I will upload of it running, it's very very smooth for what it is!


Original distributor
1g53P9h.jpg

egmmnWV.jpg


"Ac Delco" reman
JglEbpp.jpg

c8u4rk6.jpg

TXAtuph.jpg


Cardone new
ovkHXa3.jpg

G94RRs4.jpg


Now onto rebuilding all the suspension on the car which will commence next weekend!
 

gmemony2

Active member
The ICM seems to be a real weak point. I had a check engine and pulled out an old Delphi icm. Replaced with an ac Delco and cleared that code. Had a better idle. I do keep that Delphi in the glovebox though as the truck ran, just poorly when it was in.

I've always been curious about this but never read any detailed answers of why the electrical seems to be so punishing on these trucks. I've owned a number of VW's (supercharged corrados mainly) that were the same way. I always added a few grounds to those cars and cleaned up all the cra$ wiring from the factory first thing.
 
The ICM seems to be a real weak point. I had a check engine and pulled out an old Delphi icm. Replaced with an ac Delco and cleared that code. Had a better idle. I do keep that Delphi in the glovebox though as the truck ran, just poorly when it was in.

I've always been curious about this but never read any detailed answers of why the electrical seems to be so punishing on these trucks. I've owned a number of VW's (supercharged corrados mainly) that were the same way. I always added a few grounds to those cars and cleaned up all the cra$ wiring from the factory first thing.
Yea I've been thinking about adding some grounds to it. Volvos have a similar distributor/icm setup but the icm is mounted on the fender well with a massive heat sink. I am half tempted to print a dummy icm and make a pass through for the pickup wires and mount the icm on a heat sink on the firewall.
 
In your pic, that is the original ICM. (Yellow dot). So it lasted over 30 years. Why change things around (heat sinks and remote mounting) if parts last 3 decades the way they were?


But anyway, what I want to know more about is the red C4 in the background. I can't see the center of the wheel to know if it is a 90 or not.


I have a red 90. I remember the "The Syclone is faster than the Corvette" claims. They were obviously referring to the L98 Corvette, because once the rear tires hook up, this one smokes a stock-ish Syclone or Typhoon. (Ask Jason.) The SyTy gets about 3 lengths on a boost-launch, but it is impressive at how much faster this car is going when it passes the SyTy at about 6 lengths. It's big, it's heavy, it's powerful. It's pretty cool fun. So is my Typhoon, but this is funner.

View attachment 1865203
Haha ironically it's a 1990 zr1 as well!!! Bone stock around 80k miles on it. That's funny I didn't realize the yellow dot meant original. The reason why I thought it was a issue is that there were like 2 or 3 used ones in the trunk in a spare parts box that I assumed were replacement/ burnt up ones. The good thing is the distributor did fix my erratic rough idle and the timing stays dead on now. I do need to swap balancers maybe this weekend when I do the suspension work
 
replaced the balancer and sure enough it was spun quite a bit, my mark i made was pretty close luckily, i replaced the front crank seal as well with the new balancer, i made a install tool to work with the pully installer and it worked perfectly. funny enough as soon as i removed the tension off the serpentine belt the power steering pump puked all its fluid out the front seal which was nice, i have a few saginaw rebuild kits so im going to go ahead and reseal it if i cant find a acceptable replacement. i got the oil cooler lines from the housing to the block so i will do that at the same time as i do the pump. i was dedicating this weekend to all the bushings and steering components and now it looks like my list just got a bit longer! i also replaced the o2 sensor, mostly because they are cheap and i wanted to make sure its good, also gave me a chance to make sure the threads werent galled up. I also got the correct coolant temp for the ecu and the instrument cluster as well as the knock sensor. i just got the files and dusted off my old tuning laptop so i can do a bit of data logging with tuner pro, not going to modify anything just want to check coolant temps because the instrument cluster has been reading low since i got it, if the new one doesnt improve it i may have to throw a resistor inline.

tJMmHQi.jpg


KbodxsC.jpg


eRN11ex.jpg


Tvvgqxe.jpg


4y5plVY.jpg
 

Slyclone

Well-known member
Where did you source the oil cooler line rock auto ? I was actually looking at them my self and notice I have a small leak.
 
I purchased the same oil lines few weeks ago for mine. - right from GMC dealership in town. (Oil cooler to filter lines) filter to adaptor on eng block discontinued.
 
Top