Couple of nagging 2.8L Questions

[Jay Dickey]

I've asked them on other forums, and I've used google so much they offered to buy the truck and get me a moped. (Ba-DUM-Tsss)

At any rate, I have a few problems that are making me anxious, and I have a bad time dealing with anxiety since the Army... I'll number them so that I don't get confused down the thread.

1. Ok, Well I have some vac lines I can't figure out. One comes from the firewall, behind the disty, and runs to a T with what appears to be a bulb (not like a light bulb) but it's large, and... ****, here, look at the pics.

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc6/254686_2258421858497_1186915035_2744210_7697649_n. jpg

^^^ Thats the one. Where is the hose that is SUPPOSED to be attached to the T supposed to be and can I substitute it for a standard T fitting?

2. Engine is running a little too rich. How can I fix it or lean it out some? Is there an idle screw that I can manipulate to adjust my air/fuel ratio?

3. Tach doesn't work, what's an easy way to trace the issue? Which wire should I be investigating? I have narrowed it down to a white wire... but believe me when I say that my truck is an 85 and it SHOWS it's age....

4. Engine makes a clattering noise. Oil is good, other than the running rich problem. Only happens when moving.

5. Besides it's a 2.8L, it has little to no pulling power.

6. Which PCV should I use to run seafoam through the engine? I'm a FI/automotive electrical diag and repair guy... not a Carb guy.

Any help is appreciated. Thanks in advance!

J

[Jay Dickey]

Oh... also I have air, but only via vents and defrost. Someone made mention that the funny looking vacuum doo-dad is what is preventing my actuators to... actuate... and make it flow through the dash vents. Should I cap it off? There isn't another loose line around, so I wouldn't know where it's supposed to go :/

[lonniejr]

i had an 84 with the 2.8l. for future reference you need to mention year, and drivetrain (4wd or 2wd). anyway heres what i can answer in order
1. im not sure where the open is to, where does the other line go?
2. it's not the idle screw you want to adjust, its the fuel adjustment or whatever lol, its on the front of the carb near the bottom, in very center. you need a special tool usually for roughly 15 bucks, first thing i would say if you adjust it is, first make sure timing is accurate and there are no vacuum leaks. next thing is, put your tool on the screw and turn it down(or up depending on which it is) you said its rich so adjust it counter clockwise to lean it out, the truck should begin to run smoother and keep going until it begins to run ill again and then turn back a little bit and your adjusted.
3. first things i would check with a tach are the wires, what does it do? does the background light come on? first check the grounds, the power wire, and the wire going to the ignition coil. generally what i've seen happen is people change the coil and neglect to re-attach the wire. also check for breaks in wires. after you do this come back and i'll give you some more options, as well as others too probably.
4. what do you mean by cluttering noise? you need to be more specific, upper end lower end, speed? rpm? front end, rear end? what?
5. thats your problem, its a 2.8L, they have no pulling power at top performance. the only time you truely have power is 4 low, other then that you dont pull to well. also a problem could be, if its a stick and your learning to drive a manual first ever, maybe your burning your clutch which degrades power greatly temperarily.
6. personally i would just pull the hose out of the break booster and pour into there. but remember do it SLOW. there are good reasons for so. like fires if you go to fast.

any other questions hit me up, i hope i helped.
P.S. welcome to the planet noticed you just joined today

[Jay Dickey]

It's an 85 2wd, sorry about that. When I was typing all of that, I was nearly asleep. About to head out the door, so I'll answer when I get back.

[neo71665]

That tee should hook to a line that goes into the cab. That should fix the defroster vent problem and running rich.

Clattering could be all kinds of things, where is it coming from

Only one pvc and hose on a 2.8

[Jay Dickey]

The line that comes from the cab is there, there's one I'm missing, or can't find or it's just not hooked up right... I don't know offhand.

[Jay-Sliver]

That little ball/bulb thing at the T-fitting is a one way check valve I believe. Im not a 2.8L Guru...Neo is. Neo can get you pointed in the right direction (I hope)

Jay

[spideyjected]

It looks like a check valve to me too. I think if it has a check valve in it from the factory then it needs to still have one.

[Jay Dickey]

Well.... hell... Anybody know what line is supposed to go into the transverse fitting? I'd try to trace it, but I don't know where it's supposed to go. Pics are golden.:hypnotize

[Tink]

I can look on mine tomorrow when it is light out for that first thing... don't know if there will be anything like that though, mine is an 83 so non-computer controlled AND I ripped all the smog pump BS off...

The tach wiring is pretty simple... white feed, black ground and pink (I think) power... it has never worked since you've owned it? If it isn't working at all, I'd say power or tach feed...

Also, since your's is a computer controlled carb, and you probably have a vacuum leak that will cause it to run rich...

[neo71665]

Does yours have the egr noid on it, I think even on those older ones they used vacuum and that other line might go to it. I'm a bit rusty on my carb versions as its been yyears since I've been under the hood of one. Trying to find my vac diagrams but all I can find is my 86+ ones.

[Jay Dickey]

If you find them, please let me know. I'm desperate to get it running right :( It blows a puff of black smoke, not very large, but noticeable upon startup. I need to replace the REST of my vac lines, what size do I need to get?

[Tink]

I might have some diagrams for 85... think my brother's s10 Blazer was an 85 and he gave me the books he had for it... I'll look when I get home, and I'll look at my 83 as well.

[Tink]

85 2.8L vacuum diagram (this one is for an automatic)

http://api.viglink.com/api/click?format=go&drKey=258&loc=http%3A%2F%2Fblazerforum.com%2Fforum%2F1st-gen-s-series-1983-1994-tech-40%2Fvacuum-diagram-1985-s10-blazer-30737%2F&v=1&libid=1312384688204&out=http%3A%2F%2Fi11.photobucket.com%2Falbums%2Fa1 87%2Fswartlkk%2Fgeneral%2520automotive%2F85_28L_au to_vac_sch.gif&title=vacuum%20diagram%201985%20S10%20Blazer%20-%20Blazer%20Forum%20-%20Chevy%20Blazer%20Forums&txt=&jsonp=vglnk_jsonp_13123847109372

[Jay Dickey]

You sir, are the isht! I'm copying this and putting it in my archives.

[Jay-Sliver]

You sir, are the isht! I'm copying this and putting it in my archives.

Tink, is far from a sir ;)


Jay

[Jay Dickey]

Ahh, Thanks ma'am! (sorry for the typo!)