Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Like I said I'm new and I'm sure I'm gunna need some help and advice here and there. I picked up a 1978 GMC sierra grande this past weekend. Its my dd, she's not pretty but I love her. Lots of work to come. She's missing a gas tank on the right side and missing what I'm assuming is the heater core. I'll post some pics when I get home.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Welcome, I alos have a 78 gmc swb 4x4 sierra grande, bought it this last spring form Ga. It my fav to drive.

Show us what it looks like, always nice to see a new truck.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

I won't be able to put up pictures until I'm off work late tonight but I'll make that my first order of business when I get home. Even before my scotch. Its been bogging out on me and not starting in the morning. I replaced the filters and cleaned the carb so I think its my pump or the line somewhere. Once it bogs it won't start without starter fluid. It'll start to bog when I'm driving and if I don't give it a fair amount of pedal it dies. Any ideas? Also is there any known problems with the gauges system? My temp gauge barely moves even after I've been during all day. Sorry to bomb you guys with questions all at once.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Hi welcome
Is the carb stock?
any gas filters to replace?
any vac lines off the carb?
any background on it?

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Heres some pics of the body.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

I'm gunna throw an in line filter in later and run it to see if I'm getting too much air. Should let me know if its a vaccum problem. its a stock carb too btw.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

You probably just need a new temp sensor. It is located on the drivers side head. Mine did that not to long ago.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

would that cause bogging issues? Or do you just mean because my gauge is screwy.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Just because the gauge is screwy. The bog could be a number of things like timing, carb and others. I will read over the problem and then edit this post.

Ok I read over it again. I would start with a new fuel pump first. It sounds like it is starving itself for gas. If that doesn't work then check the float level and the needle and seat in the carb. Also make sire none of your fuel lines are kinked or cracked and seeping out gas.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

I had figured I would try a pump first thanks for the second opinion. I'm gunna pick one up tomorrow morning. I'll let you know how it goes.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Well i swapped the fuel pump and it shows no difference. Tomorrow I'm going to rebuild the carb. I have no experience with carbs so do you guys have any tips or links to somewhere that can help. Its the 5.7 v8 4bbl . Do you guys think a bad sending unit could make me bog as I described above? It seems to be dying a lot more frequently now too .

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Does it bog when the air cleaner is on as well? How many tanks of gas have you gone through already?

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Maybe 2 and a half tanks. Haven't tried without the air cleaner . sorry if that's a rookie mistake I'm new to this.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Chances are the air cleaner is fine. It's just a matter of narrowing down the problem. Any leaking near the new fuel pump?

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Nope no leaking and I made sure the pin was retracted when I installed it

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

No leaking and I installed the fuel pump right. I made sure the pin was retracted.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Take an empty @ dry a/f or oil jug at least a gallon , fill it with gas , cut a hole in cap big enough for 3/8 fuel line put a hose in jug @ hook other side to fuel pump inlet be sure @ tie jug to batt box or the fan or1 of the pulleys might rub on it . If bog is gone problem is between pump @ tank

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Any update and welcome to the forum! Sorry I didn't mention that before. I'm new to learning on fixing these trucks too. But ask your questions, these guys on this forum are extremely helpful!

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Just got off work , taking the carb off now after I rebuild it I'll check out the fuel system

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Props for rebuilding the carb yourself! Any luck?

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

First thing I would do. Get a Fan shroud on that thing!! That fan is not effective without a shroud.
It's also an extreme safety hazard.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Welcome, and that looks like a solid truck to start with. Appears it came with a couple spare thumbs too, good for when you bash yours while working on it. :jest:

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Update time! I did the carb and it began a whole new set of problems. I was soaking it and ran to go pick up the offspring from school and I had a buddy keeping an eye on things and he pulled the air mixture screws.... :( Such a pain in the ass. Now im trying to find a way to get to the bolts while the truck is running to set them the right way. Also as im doing this I look down to find that my fuel pump that I recently replaced is leaking now X( So im calling it a night and going back at it tomorrow. Also I am gunna throw a shroud on the fan soon.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

Im getting a LOT of smoke now and a little bit of back fire.

Re: Hello everyone I'm new around here, just picked up a 78 gmc sierra grande
 

All the smoke and back fire is from the carb rebuild? Hmm. Where is the smoke coming from? Exhaust or near intake?