Drivability problems on 91 Accord 2.2 MT

I'm hoping some of the old timers here (even the young old timers) can
recommend some course of actions here:

My car is pretty miserable to drive. There's a guy I work with who has a 92
Accord (also MT, also a 2.2l) and we were commiserating about how wretched
our cars are to try to drive smoothly.

Symptoms-
In 1st/2nd, with RPMs between 1500 and about 2700 the car seems to buck
gently. It's like I can't hold my foot steady on the acc pedal though not
that severe (not really obvious in 3rd/4th/5th, but is understandable since
ratio is higher)

It's very hard to declutch and not get jerked around. I've had other MTs
before, and this is by far the worst. It acts like the EACV is spastically
helping out and effectively blipping the throttle - if RPMs aren't exactly
matched. Admittedly, this could be due to bazaar clutch action, though
clutch is in good shape and behaved same before/after replacement.

Morning cold starts - man, this is the worst. Cold idle is about ~1600. If
you engine brake from 3k rpms (less if down hill) fuel control cuts the
fuel until rpms <1500 or so...but since cold idle is right at, or possibly
even slightly higher, it really spikes the throttle. This causes a pretty
violent surge. I pretty much have to sink the clutch before the injector
power is restored by the ECU.

Other tidbits-
I've checked PCV, seems good.
I *do* have the surging idle FAQ problem common to these 90-93, but it's
pretty mild.
I had EGR ports reamed, oddly made the car sound slightly different, but no
real change in driveability.
I know my EACV functions, but maybe it's sticky (how to test?), in other
words, maybe it's not functioning to spec.
Power is good, mileage seems good.


Folks, I would love some technical pointers on this one. It's driving me nuts.

Thanks for reading,
Arthur

 

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

You didn't mention your mileage (or country) but I'll bet your're at
about 120,000 miles? Unplug the TPS and put a ANALOG (dial) ohmeter
across the center pin and one of the others. You'll find an open circuit
at the same spot where the throttle is at your favourite highway speed.
Digital meters won't show it up as dramatically.

Shows up worst when trying to 'crawl' around a parking lot in first
gear. . . .

You need a new TPS, and a can of injector cleaner, and bleed the last
bubbles of air out of your cooling system.

'Curly'

 

The TPS cuts fuel when it thinks the throttle is closed or the voltage
goes 0.5 or less.

The TPS has, what, rivets of some sort? I hear that folks can drill,
open then replace with a nut and bolt. They tend to sell the TPS
as part of the throttle assembly- $250 estimation.

 

Thanks for the reply Curly,

I'm in New England, the car has 155k miles so you were guessing right. I
will test the TPS today if I can get the chance. Do you think that a
defective VSS would come in to play here? I don't, but I figured I'd ask.

Has anyone had an luck reworking a VSS that's making erroneous signals? I'm
suspecting noisy pulses, but haven't scoped it to see. I've had it apart,
and seen that it looks like an inductive pickup rather than a commutator.
There's a brush to the center of the pickup, but that's about all I can see
that would beg cleaning up.

Thanks,
Arthur


motsco_ _ wrote:

 

Still looking for advice on this one.

TPS checks out OK (finally got around to it). No opens-circuits in the
travel, resistance changes smoothly.

Can the EACV get sticky? Is it cleanable? What about the other air control
valves: there's a non-electronic IAC, and also some sort of cold start air
boost thing?

I *do* need to bleed the coolant, because I suspect that that is the cause
of the idle hunting a few minutes after a cold start.

-Arthur