1979 Woes
Thread Starter
Melting Slicks
Joined: May 1999
Posts: 2,230
Likes: 4
From: Allentown, Pa
1979 Woes
I have had a problem with my 79 since last fall and tonight things got worse. At highway speeds around 65, I get on the gas and for a split second the car stumbles and then it picks up and goes normal. Its hesitating when you first get on the gas. Also when its colder from being started up it will stumble and almost stall out but then I give it more gas and it will be ok.
Tonight I had it out on the highway and temps outside were mid 60s and it was running 220ish and when I got off the highway I noticed it didnt sound right. the exhaust wasnt as loud and low rumble and the rpms were about 200-300 below normal...it was idling at 400ish.
Its to warm to look at it now, I have to let it cool off but I wanted any input when I start to look at it tomorrow.
its a L-48, auto
any ideas?
:eek: :confused: :eek:
Tonight I had it out on the highway and temps outside were mid 60s and it was running 220ish and when I got off the highway I noticed it didnt sound right. the exhaust wasnt as loud and low rumble and the rpms were about 200-300 below normal...it was idling at 400ish.
Its to warm to look at it now, I have to let it cool off but I wanted any input when I start to look at it tomorrow.
its a L-48, auto
any ideas?
:eek: :confused: :eek:
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
Re: 1979 Woes (GreyGhost)
I had a similar problem. My secondary windup spring loosened all the way up. I'd check the secondary air valve flaps. Mine had NO resistance.
It sounds like it could be a bunch of other things too. I'm sure others will offer other things to check as well. Just sharing my experience. :D
It sounds like it could be a bunch of other things too. I'm sure others will offer other things to check as well. Just sharing my experience. :D
Burning Brakes
Joined: Sep 2002
Posts: 1,179
Likes: 3
From: SF East Bay CA
Re: 1979 Woes (GreyGhost)
Check your Carb secondaries. You should be able to just touch them while the car is OFF and they will open. Also check your distributor weights. you need to have them moving and quick so they will advance timing. I reworked mine as I would tend to bog between shift points, but I also added a different tranny (700R4). You may be running too lean as well. Maybe too much fuel also.. Alot of variables.
1st: Check secondaries
2nd: Check timing
3rd: Check dist weights (and cap)
You may also want to check out Lars tuning tips for Q jets in the archives.
1st: Check secondaries
2nd: Check timing
3rd: Check dist weights (and cap)
You may also want to check out Lars tuning tips for Q jets in the archives.
Thread Starter
Melting Slicks
Joined: May 1999
Posts: 2,230
Likes: 4
From: Allentown, Pa
Re: 1979 Woes (timbo79)
Well it was a simple fix. I looked around the engine on saturday and found that one of the big vacuum hoses from the front of the carb had some rub marks and a big hole in one of them. I replaced the hose and since it was saturday..that means rain here in Pa, I did not drive it till today but that was the problem. The car ran fine, really good actually.
thanks to everyone for their insight on the possible problem. :cheers:
thanks to everyone for their insight on the possible problem. :cheers:
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Re: 1979 Woes (GreyGhost)
That is probably the PCV hose. I realize the problem is solved but another thing to look at is the accelerator pump linkage. When I had my Q-Jet rebuilt the linkage was a bit off causing a mini-bog. Adjustment is by bending, yes bending, the linkage. That's the way GM designed it!
