carb fuel problem

[ChaseR]

OK my 88 LX carb seems to be having issues.

now it only does this when its warm but I will be driving and it will lose all power all of a sudden when below 4000 RPM, If I pump the accelertor pedal it gets going again (being all jerky) until I hit 4000rpm and then all is well through the power band. like i said before it usually only does it when it warms up a bit. I did a test!

I first stoped the car (manual trans) pulled it out of gear and floored it, it went to 3,000rpm and stopped, engine still running but not gettin fuel! When I Pumped the gas it jumped past 4k and ran normal.

Then I got out popped the hood and pulled on the throttle cable, same thing happend, If i let the cable go and pull it again real quick it revved real high again. I am totally stumped on this one! SOMEONE RESCUE ME! :owned:

[ChaseR]

i changed both filters, lines and the pump to, still having this problem. I was unable to find any vacuum leaks...

[A20A1]

sounds like a vaccum leak... or maybe to one of the thermovalves... the bliping (quick trottle then release) builds up vacuum in the manifold and is probably creating a temporary good vacuum situation which causes your distributor advance and other vacuum operated parts to function normally, but when the vacuum fades the problem reappears.

[ChaseR]

OK I went back outside and started it, I hear what sounds like a leak towards the back but I just cant find it! Ugh I hate carbs. But since it only happends when its warm is the the probobale cuase?

[A20A1]

hmm have you ever removed the aircleaner? I think it might be a busted vacuum line, or the end of the vacuum line expanded and is leaking... if the thermovalve is cracked or stuck it will cause vacum to bleed... you also have a large vacuum hose form the rear of the manifold to the brake booster that could be leaking... do you nottice the car stalling or losing rpms when you apply the brakes? Other then that internal vacuum leaks from maybe the carb top-hat gasket getting old would be hard to locate using carb cleaner... plus the sound of the carb operating usually overpowers the sound of the leak.

[ChaseR]

well i dont notice power loss during braking no. I do have a flipped lid though, where is this thermovalve so I can see if its ok?

[A20A1]

rear right corner of the intake manifold one has 2 vacum lines and the other has 3 vacuum lines... there is also one thermovalve on the thermostat housing near the distributor... it has 2 vacuum lines.

[ChaseR]

so do you think it could be this...?

http://www.members.aol.com/magman2x4/valve.jpg

[ChaseR]

also it seemed this happend about a week after I cut my cat off, could have have anything to do with it?

[ChaseR]

would me ECU under the seat tell me anything?

[A20A1]

those hoses aren't connected? that pic is really blurry... anyways if the ports on that thermostat are broken then that sucks

the vacuum from that vavle goes to the secodary diapragm. I suggest you find vacuum caps and plug #17 and #28 at the hard line. don't worry about the thermovalve.

[ChaseR]

yeah they are not connected, sorry for the blurries. $40 digicam! so 17 and 28.. What do you mean by Plug at the hard line?

[A20A1]

the hard line is the metal vaccum lines that are circled by the upper right question mark in your pic.

esper05 is my aim, did you get my IM?

[ChaseR]

A20A1, I love you, you are gods gift to cars! i plugged those off and the thing huals ass. its kinda sluggish somtimes but it sounds so much better now, it runs better than ever! Its normal up to 4k but when it hits 4k it feels kinda like a vtec and snaps to redline.

[A20A1]

A20A1, I love you, you are gods gift to cars! i plugged those off and the thing huals ass. its kinda sluggish somtimes but it sounds so much better now, it runs better than ever! Its normal up to 4k but when it hits 4k it feels kinda like a vtec and snaps to redline.

wow, so flattering... blush
lol
anyways glad to have helped. :)