The car starts fine for the most part. After startup if i try and accelerate down the road i just get a lot of black smoke out of the tail pipe and no power. The RPMs will not go above ~800-1100. Once the RPMs manage to climb above maybe ~1200-1500(which could take up to 20seconds of just giving it gas waiting for it to kick into gear) it will all of a sudden kick into gear and run smooth. Once it stops doing it that first time most of the time it runs and idles perfect. If you then shut the car off and start it right back up it will then do the same thing. No power getting to engine,Climb above 1500 RPMs and start running good, Run fine until you shut it off again.


It makes me thing its something electrical since it only happens after you turn the car off. I changed the oxygen sensor. Maybe the OVP relay? Someone at some point had messed with the ?lambda tower? as i believe there is supposed to be a ball bearing in the top and that was gone, it idles so good otherwise i wouldn't think that would be the problem anyways.


I have been trying to research it but it seems like there are so many components to the fuel system im kind of lost on where to start. Any help is appreciated.

A new fuel pump relay did wonders for my SEC starting / cold engine issues.

I recently had both my fuel pumps go at the same time(leaking out of the crimp) so i replaced the pumps/filter/relay all at the same time within the last year or so. I was thinking maybe the accumulator is bad and its losing fuel pressure and causing it to lose power? Just seems weird that it only happens if i turn the car off and back on.

https://www.landiss.com/mixture.htm

I will give that a try in a day or to thanks for the advice. I have been reading through the instructions and had a couple questions
1.
"3) Detach the purge line at the electric switchover valve and seal. On my car, this valve is mounted on the inner wall of the left fender, adjacent to the ABS controller. The subject line is black tubing with white stripes".

I cant seem to find the switchover valve is that the correct name of the part i should be looking for? I attached a picture of what it may be but im not sure.

2.
"1) Idle Contact: Deflect the air flow sensor plate. The duty cycle should decrease to 10%. If it remains at 70% test the throttle valve switch (Job 07.3-121)"
What is the definition of deflect here? Judging by the next line being

"2) Full Load Contact: Open the throttle completely. The duty cycle should decrease to 20%. If it only decreases to 40% test the air flow sensor potentiometer (Job 07.3-121)."

does deflect mean to just push it down slightly and open throttle completely means to push it down all the way? I would think throttle would mean throttle linkage but that would have no affect on the airflow plate if the engine is not running?

https://gyazo.com/a59706e40036035f6dd7172216baf59a

check the basics-sounds like too much fuel or not enough spark.

too much fuel-leaking injector and/or fuel dist. MAYBE co is too high or the eha isn't getting correct orders. o2 sensor could be way off.

not enough spark-tired plugs ,wires, cap, rotor and or coil. look for any discoloration at the coil bracket. any white you see is spark escaping, looking for the path of least resistance.

So i did the tests today and everything at first seemed close enough but still off i went ahead and did the tests with engine on anyways.
Key on engine off:72%(3.75v)
plate down:18%(11.15v)
throttle open:27%(9.9v)
With the plate down and letting it back up it would go to 45%(7.45v) If i manually pushed the plate down maybe a 1/16-1/8 an inch it would return to the 72%(3.75v) but go back to 45%(7.45) when let go. It would only return to 72%(3.75v) fully up if i turned the key off and then back on again.

@ 2500RPM:30%(9.55v) Was steady 9.55v maybe fluctuating at times up or down .01-.05v
Adjusted @ idle to around 41%(8v) it was moving around between maybe 7.5v-8.5v. When i had first let it idle it was steady 13.08v i figured it was in open loop or something but it wouldnt change so i turned the screw ~1/8 turn CCW and it started reacting and adjusted from there think maybe i did 1/4 turn CCW but there was some back and fourth i didnt keep track.

Took it for a drive and it still had the same problem so i brought it home to check it again and with key on it was 8.69v and running it was 6.67v steady even after a few minutes.
I tried turning off and restarting and it went to 3.75v again at key on engine off but with engine running the readings were just so random counting up to 13v and down to .08v and did not seem to react to adjusting the screw at all. Every time i shut the car off and on seemed to produce a different set of results.

Kind of lost. I suppose my first steps would be to get the engine off numbers perfect? I believe i read there was some dowel pin to adjust the height of the plate if i need it down a 1/16 and take a look at the throttle valve switch/potentiometer.

I dont believe there is a fuel leak cant see or smell anything. Do you think i should try adjusting the EHA to lean it? O2 sensor is new was from Bosch i would hope it good.


I have put new plugs in. I believe the wires are relatively new. Rotor and points look to be in decent shape. I will check the coil out. Thank you for the advice.

leaking injectors or fuel dist will not smell like a fuel leak, only run rich.

do not adjust the eha.

MAYBE adjust the co with a meter on the eha looking at amps and another on the 10 pin connector looking at voltage. i also use a 3rd meter on the o2 wire and see how the sensor reacts.

i would give it to a shop and scope the ignition. just 'cuz it looks new doesn't mean it still works like new. have had 4 different sets of bosch wires on 3 different 450/560s out of the box run bad. now it's beru, karlyn or bremi, if you can find them for wires, never bosch for 25 years now.

May be a dumb questions but what is co referring to?

Also just some updated symptoms on my problem. Awhile ago maybe 4-6months this exact same thing was happening and i changed the plugs and it seemed to go away. I then went on to adjust my high idle by messing with the ICV which involved pulling a sleeve out of the housing a 1/8 of an inch or so which dropped my idle from ~1200 to ~750 but thats when the problem started with getting no power to engine again. I reversed that today and pushed the sleeve back in which raised my park idle up to ~1200 and drive idle to ~900 and it accelerates fine.

I dont really want to drive it like this as it slams into gears when you shift. Im just not sure if changing ICV was causing the acceleration problem or having a low idle was causing it. Or if it has to do with anything as i had the problem before i messed with any of that but it did seem to go away before changing plugs.