98 Civic fuel economy: torque converter lockup?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

randyoo@gmail.com - 09 Jun 2007 23:02 GMT

On Mar 28, 5:04 pm, rand...@gmail.com wrote:

> I've had an intriguing issue with my 98 Civic, and thought I might
> describe it here, and see if anyone has some insight as to what could
> be going on with the car.

[snip]

> what, but the alternator is only spec'ed at like 80. I thought that
> maybe there's a wiring problem that may be causing a load on the
> alternator all the time, hurting my fuel economy. (I "only" get 25
> miles per gallon)

Hi guys,

A few months ago I posted about my poor fuel economy, and how I
suspected an electrical problem.

Suddenly I'm getting mid to upper 30's MPG, and I think I know why:
I'm pretty sure the torque converter wasn't locking up at highway
speeds. I haven't the faintest idea where to even start
troubleshooting something like this, or if it would even be worth the
time and effort on a 10 year old vehicle with 150k miles.... But I
*was* thinking of wiring up a manual override toggle switch, if it
stops working again. Get on the highway, set the cruise, and flip the
switch.

Any thoughts?

Reply to this Message

jim beam - 09 Jun 2007 23:17 GMT

> On Mar 28, 5:04 pm, rand...@gmail.com wrote:
>> I've had an intriguing issue with my 98 Civic, and thought I might
[quoted text clipped - 21 lines]
>
> Any thoughts?

you can hear whether the converter is locking - and see revs if you have
a tacho. it's the "fifth gear" rev drop.

if the solenoid is defective, it's relatively cheap and easily
replaceable. you should also get a code on the ecu. if it's not
working, but you get no code, check whether the ecu's giving signal to
the solenoid. wire an led in parallel with the solenoid circuit and you
can see it activate. or not. tegger has pics of the tool i made for
this exact task this past winter.

Reply to this Message

randyoo@gmail.com - 11 Jun 2007 04:53 GMT

> rand...@gmail.com wrote:
> > On Mar 28, 5:04 pm, rand...@gmail.com wrote:
[quoted text clipped - 32 lines]
> can see it activate. or not. tegger has pics of the tool i made for
> this exact task this past winter.

Jim,

Thanks for the reply!

That makes perfect sense: find out if the ECU is telling it to lock or
not, and then I'll know if it's the solenoid or the signal out of the
ECU. I assumed it was the ECU not giving the signal to lockup, but now
I've got an idea of where to start now, at least. Thanks!

Reply to this Message

motsco_ - 20 Jun 2007 04:21 GMT

> On Mar 28, 5:04 pm, rand...@gmail.com wrote:
>> I've had an intriguing issue with my 98 Civic, and thought I might
[quoted text clipped - 21 lines]
>
> Any thoughts?

====================================

If your thermostat is opening too early, or your reservoir isn't full
enough, (air in cooling system) the computer never generates the lock-up
signal. Check both.

'Curly'

Reply to this Message