Solid20vq

Okay, so white hose #2, which comes from the driver side firewall and runs beneath the battery is actually a very faded pink, the diff lock.

I hooked the other white hose to the cruise control pump, now I'm going to go get some coffee and breakfast, let her warm up, and see what happens.

IdahoDoug

So, the yellow/black vacuum valve already has 3 lines on it? One at each end, and on on the bottom of the yellow (literally the bottom where it's hidden from view)? Just want to make sure. I'll go take a better look for the white plastic hose, but be careful hooking up a vacuum line randomly - especially to something that can affect the throttle (cruise part).

DougM

Solid20vq

So the butt-dyno says throttle response is a little better, and the power curve feels more consistent. Unfortunately the engine still struggles once I engage the clutch; RPM drops to about 400-500, wavers once or twice, and then evens out at 800.

Most of my driving to and from work doesn't involve a lot of stops, so this doesn't really hinder my day-to-day driving. On the days I do drive around town a lot and the engine warms up more, it has been more prone to stalling at stops. But this was before I connected the fuel pressure regulator vacuum hose, the white hose to the cruise control pump (which may be incorrect), and the mystery hose to the pink diff lock hose.

I pulled the codes last night and got all 4s, no faults.

I was perusing the service manual and found this interesting little bit:


Though I received no fault code, the symptoms are an exact match. Would this apply to my early 7A? Also, the transmission speed sensor, is this different from the crankshaft pos sensor? I changed one of these, either crankshaft pos or engine speed sensor (same?), but I don't remember which one right now.

There are a few other factors which may be throwing me a curve here. First, when I took it to a local dealer-alternative european shop to get the timing belt and water pump changed, they advised replacing the fuel pressure regulator (FPR). They couldn't find the FPR specific to my 7A so they put in one from a 200, it has a lower pressure rating, but the head tech said the computer would accommodate and bump up the fuel pressure. Does the ECU remap itself and save the settings, or does it return to default every time the car is started and then adjust from there? Second, I wonder if the Hitachi injectors are causing some difficulties. My idle has an intermittent bump to it, making me wonder if they are a bit clogged.

thanks for the help

Solid20vq

Yep, check valve has 3 lines connected to it, two larger diameter, and the small black, with cloth cover.

yodasfro

The white plastic vac. line definitely doesn't go to the cruise control it's for the climate control and should hook up to the check valve. The cruise control is self contained and not hooked up directly to engine vacuum.
Yes having the 20vt 3B FPR is 3bar vs. the stock 7A FPR that is 4.2bar so that isn't a good thing especially with the stock hitachi injectors you are probably running lean.

IdahoDoug

I'm not finding a white vacuum hose in the area. So where does this hose "pulled toward the camera" connect on the other end? It's Sunday morning and I have time to help you for a bit, so waiting for the answer on that, and confirmation that your yellow vacuum valve already has THREE vacuum lines connected to it - two on the yellow part, and the one on the black half.

DougM

yodasfro

The white line is for the heater valve.

Solid20vq

Roger, hooking up random vacuum hoses is a bad idea, especially to something associated with the cruise/throttle; in retrospect I realize that was a pretty stupid move Thanks for the pointers.

In that case, this white hose is for the climate control? It disappears beneath the battery.

Solid20vq

I'll trace it, but the pink hose and this white hose are two different hoses. Climate control (black hose) works without issue.

I'll go climb under the car and trace the white hose which goes beneath the battery. I've hooked the pink diff hose up to my original plugged hose, I'll check to make sure it is fully intact.

yodasfro

Ok I got it now ignore my previous post about the pink line being broken.
The white line would go to the heater valve that has been bypassed on your car. Do you have manual or digital climate controls? So cars came with a heater valve some did not just straight pipe with sensor. You need not worry about hooking it up unless you replace the heater valve. For now just cap it off.