I had to change a hose and i took out the distributor to get easier access to it and now when it gets to operating temp it idles really rough up and down idle almost sounds like its starved for fuel... can anyone help me on what i should check.. thanks

 

Welcome new member!
Did you set spark timing with a timing light?
Did you bleed ALL the air out of the cooling system?

 

no i didnt set any timing i was told that the distributor was all electronic so it only would go in one way... and no i didnt bleed the air out of the cooling system either... what would be the best way to do that? And air in the cooling system really make it run that bad?

 

I have a 93 Accord which should be the same as a 91 for this. The three mounting bolts for the distributor have to be loosened so you can rotate the distributor slightly while using the timing light.

There is a rubber plug on the front of the engine that you pull to see the flywheel. Refer to a good manual for the exact procedure but I have one tip. There is a mark that shows up under the light for top dead center and then there is a group of 3 marks which is where you set the timing. If you try to line up on the tdc mark then it will be way off.

Not sure about Honda's with air in the cooling system but my Chevy Silverado with a V6 runs really badly if the coolant gets too low.

 

well i bled the cooling system it made no difference.... i know how you mean to time it like that but it doesnt do anything different no matter where you rotate the dizzy but it idles fine cold but the hotter it gets its misses and barely runs at all fuel pressure is good i cleaned throttle body it has new wires new cap rotor plugs... anymore more help would be appreciated thanks

 

The spark timing is supposed to be adjusted. I'm surprised that spinning the distributor didn't make any difference.

Air flowing thru the cooling system will confuse the FITV & IACV, which are parts of the idle control system. There's a bleed valve on the thermostat housing, looks kinda like a brake bleeder. Open it to let the air out, until you get no more air bubbles. Refill at the radiator cap.

Look for instructions on setting the "BASE" idle. I'm a little hazy about 91, there's a coupe extra components that I never had to deal with, but here's cliff-notes...

Fast-idle thermo valve is bolted to the underside of the throttle body. Search "FITV" for instructions about opening that & tightening something inside. When it works loose, it causes the idle to surge up & down. That FITV is supposed to be completely closed when the engine is warmed up.

When you say it misfires & barely runs at all, it sounds maybe worse than an adjustment problem with the idle control system. What about a coil or ignitor that's starting to fail as it gets hot?

 

i bled all the air out of cooling system doing what you said.. i turned in the FITV and cleaned the IACV i got rid the up and down idle and high idle but still as soon as it warms up it runs really bad i was thinking a bad ignitor or coil too do you know how i could test these to make sure before buying parts?
thanks

 

IIRC, there's something in the DIY section about "how to diagnose coil vs. ignitor" or something like that. I don't remember the details.

Problems with the FITV & IACV, or the base idle setting, usually result in surging idle. Acts as if you're using the gas pedal to rev the engine. Misfiring, sputtering, stuff like that seems to me related to ignition.

How about old, fouled spark plugs?
How about old spark plug wires with decaying insulation, shorting to ground?
(just ideas for you to rule out)

 

ok thanks ill look for that... but as for wires and plugs i just changed them about a month ago and all the plugs look to be good but im gonna try and figure out the coil and igniter thing thanks for the help ill figure it out sooner or later lol these hondas are confusing to me lol

 

Does your check engine light come on? If so, short the service connector to get the codes.

When the engine warms up, the ECU starts using certain sensors to adjust the air/fuel ratio. The oxygen sensor and coolant temperature sensor are two that come to mind that would cause the car to run poorly.