Hello to all, I have a 90 Accord that has doveloped a low rpm miss 1500-2500, that I have not been able to solve. I have replaced the plug wires,checked distrubitor cap, fuel filter and checked for vac. leaks. No codes are bieng displayed. Any advice as what to look for or what might be the problem. Thanks
JRP

 

As a test, try disconnecting the vacuum line to the egr valve. Does the problem go away like that?

 

on top of Chio advice,,

you mention that you replaced the plug wires how about the spark plugs?? what brand are they ?

might have EGR passage blockage

 

Thanks for the replies, the problem seems to be the egr system as you guys suggested, when I unplug the vac hose from control box to egr the miss clears up but the check engine light comes on. I'm getting vac. to and thru the egr sv.in the control box to the egr. The egr sv. in the control box checked ok when I applied 12v to it. I couldn't check any farther because I don't have a test harness to test the egr. I followed the flow chart in the service manual to this point. The plugs are new NGK's. Thanks
JRP

 

Hey there Jary, I see that we never Welcomed you to the forums when you joined...Thank you for joining [sm=happy046.gif]

Stop in at the new members area and announce yourself...it's easy![sm=bounceybounce.gif]

WheelBrokerAng [sm=americanasmiley.gif]

 

You probably have some clogged egr ports in the intake runners. You'll need to clean them out. Maybe DH has a how-to around here somewhere?

 

in a nutshell

1. Remove fuel rail
2. drill out rivits holding on access cover
3. remove access cover and soak in brake fluid or something similar
4. use a pipe cleaner to clean out intake ports (4 of them)
5. tap rivit holes on intake for 10-14mm bolts
6. reinstall access cover using same size bolts that you tapped the holes for

 

there is a write up on our DIY section

how to CLEANING EGR PORTS ..

But if there is vacc ad dile at the egr hose ,, and car stumbles .. it means that egr valve is staying slightly open ,, i do not think that the cause is egr ports clogged up ..
if that ws the case the engine would still miss even when he disconnected the hose from egr valve ,,

he has to diagnose and repair why there is vacc at idle at egr hose, going to valve,, there should be no vacc there at idle

 

I think your right DH I'm getting vac to egr. I'm going to pull egr somtime this week, it will probably be this weekend. I would like to find a test harness to check the egr's output. I'm running car with vac. disconnected from egr,no miss but the check engine light stays on. I'll let you guys know when i get it fixed. Thanks for all the advice, you all put me on the problem.

 

Didn't realize it was an idle problem. Sorry.