Jump to content




Carb Re-Build/devac?


  • You cannot reply to this topic
15 replies to this topic

#1
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

Hi everybody, I am in the process of rebuilding my carb for my 1985 CRX and am wondering if I should do a devac at the same time. I have read in a couple different posts that "The car should be running well before you devac" but since the carb is out of the car and would be easier to re-assemble if I did the devac now, should I devac at the same time as I rebuild, or should I put everything back to stock make sure it's running good and then devac?

Thanx in advance, Matt 

*Note: First carb rebuild that I've ever done, so I want it to be simple, but I do have 10+ years of automotive tech. experience so I understand the automobile pretty well. :)



#2
PowerWheels86

  • Leadfoot
  • PipPipPipPipPip
    • Group: 2015 Contributor
    • Location:Houston, TX
    • Drives: 1986 CIVIC Si
    Garage View Garage

I'd recommend getting it running well first... but then again, i did a Weber carb swap and devac at the same time and the car ran great!! It's just that doing the devac without the car running well to begin with you don't know what to track down if there is an issue or line that's supposed to or not supposed to be capped... when i was trying to do my devac i spent about a month researching it before committing... 


Dark Side of the Power........
Posted Image


Wheels

QUOTE (RARECRX @ Jun 26 2009, 06:55 PM)
The ONLY BMW's I like are (Beautiful Mexican Women)

#3
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

Ohh yea I've been doing a good amount of research myself, still not enough though. I think I might just put it all back together get her running like a top and then devac. Thanx PowerWheels.



#4
niccer

  • Slowpoke
  • PipPip
    • Group: 2014 Contributor
    • Location:Atlanta, Ga
    • Drives: '87 Civic Si, '11 F150 Ecoboost

Note:  I'm someone who got frustrated with tracing a carb/vacuum issue with his DX and just swapped it all to be fuel injected.

 

I would imagine if you devac'd it, you'd have fewer problem areas to worry about.  On face value, it seems like you'd have an easier time figuring out any problem areas. 



#5
3rd gen sinner

  • Slowpoke
  • PipPip
    • Group: 2016 Contributor
    • Location:Tampa FL.
    • Drives: 15 Kia Sorento, 86 Civic
    Garage View Garage

My car did not run right before the devac. I followed the devac thread and had no issues after.



#6
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

^^^ That's good to know, because my car was running like $h*t before I pulled the carb for a rebuild. I'll let you guys know how it turns out. Hopefully I'll be able to get the rebuild done this weekend.



#7
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

OK, it's rebuilt, but...  It has trouble coming off idle.  It stumbles under any load while the engine it at lower RPMs (lower than 3k)  Climbing hills is difficult and it sputters and looses power.  I have to down shift to get the car up the hill (most times into 3rd at about 50MPH).  I have tried to adjust the float bowl level with the "forbidden" yellow screw because the level is too high.  I am wondering if it is flooding out?  At highway speeds it runs alright, except for the lack of power on hills.  Around town is a different story.  I came to a stop and tried to take off and the car died.  I sat and cranked for 5 min. until I finally got it to start and it drove fine for a bit then stumbled and almost died at another stop sign.  I was able to keep it running by giving a little gas.  I have replaced most of the fuel lines under the hood, need to do one more then those are all done.  Any thoughts?



#8
WhereIsMyWrench

Check for vacuum leaks. Just start it up and spray some carb cleaner around the base of the carb, the intake manifold gasket etc. Listen for a jump in rpm. I realize that doesn't solve your float level issue but it's something good to check.

#9
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

^^^ I can do that.  I think I might go ahead and do a devac while I'm at it.  It stalled out again today, only this time it was on an off-ramp, very unfortunate, and I had to push the car out of the way until I could get it to start 5 min. later.  I then had to keep the RPMs above 1000 to keep the car running.  It idles fine when it is cold but when it warms up it wants to die.  It also started, this morning, to sputter and loose power while driving on the highway when I try to give it any more gas (push the pedal down more).  Any other thoughts other than vac leak?  I am wondering since I replaced the fuel bowl level screw, did I mess this carb. up beyond repair?  I hope not because I need this as a reliable daily driver.

Thanx for the input guys,

Matt



#10
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

Bit of an update.  I found there to be a vacuum leak at the intake manifold gasket and it seemed like the egr valve gasket was leaking as well.  I just got a hold of the parts and I'm about to get started.  Wish me luck :)



#11
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

Done! This car runs pretty good now.  I replaced the intake manifold gasket and did a "devac".  Also had to replace CV boots, but that's another story.  I drove it to and from work (95 miles) and it ran smooth on the highway even up into the Rockies back to my house.  The idle is pretty good ~1000 rpm, little high...  The only thing I noticed was a little bit of backfiring on decel.  My exhaust has a pretty big hole right in front of the muffler, so that just amplifies it, but I'm wondering if anyone else noticed this after a devac? Thanx for the help guys, I appreciate it.



#12
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

HELP! I can't get this thing to start consistently.  It starts sometimes when it's warm(ish) outside, but even then it is occasional.  It also started one morning a couple weeks ago, cold(ish) outside...  I know it is running rich and I'm wondering if my elevation ~8500 ft. has something to do with it not starting, because there is less oxygen??  Is there any way to lean the carb out a little bit?  I think it is just flooding itself out while cranking, and it seems even while sitting (too much pressure in the tank?).  I also noticed excessive pressure building in the gas tank and it even blew some fuel out when I removed the gas cap.  Is there a vent for the tank that I may have blocked off when I De-Vac'd?  Any ideas would be greatly appreciated.  Thanx pepps.



#13
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

BUMP, please, anyone?



#14
The Quaff

  • Slowpoke
  • PipPip
    • Group: Members
    • Location:Barre, VT
    • Drives: 1985 CRX, 1998 Acura Integra

Bump... Anyway to lean this carb out? Does anyone know?



#15
circuit-maker

  • Granny
  • Pip
    • Group: Members
    • Location:Pacific Northwest
    • Drives: '85 Honda Civic 1500 S, Red Hatchback
    • Image Gallery

Did you ever get this figured out, man?

I just acquired an '85 1500 S (Honda Civic, of course.)  Its the 3-door hatchback. 

I'm not sure what a devac is, or I'd help you out. I'm very much a beginner, but I'm stoked to work on this beauty!

 

I would be interested in chatting with you about this car; first thing I'm doing is replacing all the filters and sensors I can. For example, air filter, PCV valve, EGR valve, the thermosensor for the radiator fan, the O2 sensor, ... I may be forgetting some; still waiting on the parts shipment. 

I'll also be replacing all the suspension bushings, and pretty much rebuilding the front suspension (the rear will happen next, budget permitting!); I also had to replace the CV joints, and opted to just buy the whole unit around $30 for each side. Not bad.

 

All in all, with a starting price of $750 for the car, I'm only in about another $300 bucks. Hoping to do a full restore and make this a snappy little drive-to-town-and-bigger-cities car. I hope your restores have gone well, and also hope for any tips/pointers from you, as this seems to be rather a rare car in the honda-fan world!