1988 Accord idle surge when warm

Hi. I just purchased an '88 Accord LX Auto yesterday. It sat for 2
years without being started, and I started it up within 30 seconds
with a new battery & some gas. 213K miles on the odometer.

It runs great when it's cold. It's got power, starts right up, drives
nice.
When it's warm, the idle surges between 600RPM [15 seconds] 1500 rpm
[15 seconds] and then 2500 rpm [15 seconds]. Then it repeats.

When I give it gas, it bogs down the RPM until it dies.
If I press the gas slow enough it will rev up to 3K before it dies.

ONLY when its warm!

Which sensor could be going out? Or is it a gizmo attached to the
carburetor? Maybe the radiator was filled without bleeding the air
bubble out of it? The guy that owned it knew nothing of mechanics.

I come from a Chevy world, building oldschool V8's. :]


ANY assistance would help! I don't know who to talk to about Honda
tech.

Thanks


Sean

 

A good place to start is to make sure the coolant system is full - no air
space in the radiator. If the coolant is low the temperature can't be
measured reliably and the engine will surge. Weird, huh? It seems to be a
Honda quirk.

Mike

 

It's absolutely topped-off. I can run it for an hour, get it really
hot, and take off the cap some minutes later & it's still absolutely
full.

I looked for the ECU to get some error codes from it -but I can't find
it.

I looked for the purge valve to bleed the air out of the coolant
system - I can't seem to locate that either...

Vacuum lines look well taken care of. Hm.

Think this will pass emissions in Washington state tomorrow?





UPDATE:

It doesn't bog-down when hot. It runs fine when it's hot, but the idle
still surges.

Idle will not surge in gear.

 

i had something like that on my 87 and it was the some sort of choke
issue with the carburator.
i forget exactly but it was a relatively minor fix that he jerry-
rigged...cheaper than a new carburator

 

ha.. Thanks, but my choke is working satisfactorily. I've got a nice
shop manual now. I've got 30 or so pages that troubleshoot this issue.
Sweet, 4 hours of systematic vacuum/power/frequency analyzing.
Freakin' Hon-duh.

 

wrote in

Newer Honda/Acuras are not so bad;they have EFI and fewer vacuum lines to
deal with. No choke,either.