New Member, Question About '84 Sierra

[hogodog]

Howdy to All,

Just got an '84 Sierra 1500. It has a 305, Quadrajet, HEI Dist., TH-350 tranny. It's hard as heck to start, then runs like it's on 7 cylinders and real rich until it warms up. Then it smooths right out.

Can this be related to the evaporative emmisions **** and all the vacuum lines and switches? Is there a computer on this year/model of truck? Can I abort all this?

I tried to find a similar thread without much luck. Any help or direction will be appreciated.

Thanks, John

[hotrodpc]

Welcome the forum Dog !!! Could it be your auto choke is to tight and is sticking fully closed, and not backing off much once it does finally start? The butterfly has to be open at least a little to let air in, or it will just crank like crazy acting if it might start but won't.

If there is a computer on it, I am sure there is for 85, but for 84 I think it would have had to be CA emmssions vehicle. IF so, you can tell by looking at the carb. On the passenger side up front on the carb, you will see a plastic round hood type object. That would be the AF mixture solenoid and therefore a computer opp vehicle. I believe it would be Computer Command Control aka CCC. If you have the factory tailgate and it says ESC aka Electronic Spark Control, those are usually comptuer equipped vehicles also.

[hogodog]

Thanks for the reply hotrodpc. I checked the choke. It was a tad snug but adjusting it did not improve anything. It just cranks and acts like it wants to start, but won't fire...

Nothing extra on the carb or the tailgate, so it must not be a computer version rig. It was sold new in NE Oregon.

Initially I found some cracked vacuum lines. Replaced all bad looking ones and checked fittings. Seemed to improve starting a tad, but now it won't fire up at all... read somewhere where the emmision system does all kinds of interaction during and after startup/warmup, but I don't understand any of that tech talk... I grew up with stromberg carbs, points in the distributor and tune-ups done by "ear"...

I'd like to tear out all the smog stuff and get back to basics...

John

[hotrodpc]

If it is not computer controlled, shouldn't be much smog on it other than maybe the AIR pump and an EGR. Have you checked the EGR to make sure its moving freely and not stuck open? Also when you say it won't fire, are you saying its not getting spark?

[leolkfrm]

is the vac choke pull off working? if it has been like this a while new plugs are in order

[hogodog]

The AIR pump was removed before I got it. Everything else pertaining to emissions seems to be there, as far as I can tell.

It was getting spark, but I'll recheck just to be sure... Before the no start, I started it, got it warmed up thru the rough running to smooth running, then moved it to another driveway, brought it back later in the day, then no start the next morning...

Couple dumb questions... Where is the EGR, so I can check it? Where is the vac.choke pulloff? Is it the big round diaphram looking thing right next to the distributor? It has vac. lines coming out of it and a rod that connects to the carb.

Thanks!
John