It's still not right!
 

OK I changed all of the vacuum hoses on my '75 1.8L L-Jet and clamped them all off, but I still have a problem with rough starts.

When I take off from a dead stop the car kind of "bogs down" and RPMs drop very low. If I just let it run its course keeping the gas pedal where it is and not letting up or juicing it then once it kicks in past about 1500 or so it springs to life and runs smoothly along the rest of the power band. Not sure if this is related, but I also notice that when I rev it in neutral and take my foot off the gas the RPMs drop VERY quickly. This might also be related, but if I drive it a short distance, turn it off, then get back in it within an hour It will hardly idle. :mad:

I don't regret the work so far, it needed it and I notice it's much smoother, but it still isn't quite right.

Any suggestions? Other than starting off at 3K RPM every time? :eek:

Thanks a lot for the help,

Does the door in the air flow meter move smoothly? You might have worn tracks in the AFM - a resistance check as you move the door by hand can check this.

the rev's drop quickly or the tach drops quickly. if it's just the tach, maybe your losing spark. could your distributor be worn and vacuum inputs change point gap or something along those lines

you may have covered this in an earlier post. sorry if i'm a come lately

PD

Well... the tach definitely drops quickly, which might be an ignition thing. The timing/etc was set a while back, like May or so. The thing is it doesn't seem any worse since I changed all the hoses. In fact, it definitely got better. It used to idle very low much of the time, now it only does that when I re-start it when its hot. I've always wanted to switch to a pointless system. Maybe I'll do that now just to get that out of the way.

Or.... I could just hit it with a BFH like I wanted to yesterday, drop the 1.8 and put something bigger in there..... :D

Thanks for the responses. James, I am going to check that air flow meter too.

Is the deceleration valve in good shape? I'd also check the head temp sensor and the wire that runs from it. When I had a 1.8, those were my troublespots (the loose wire was really hard to find until I accidentally bumped it and the car died).

Taking off the air sensor and checking the airflap for smooth movement would also be a good idea ---- and you can also check the resistance from the sender there at the same time, as James suggested earlier.


One subtle vacuum leak that's not associated with the hoses can occur with the o-ring on the oil filler cap. If it doesn't seat quite right, strange things can happen

I third the motion to check the air meter... I had one once that would stick at the high end of the range.... When it stuck and you came off high RPM... the car would bog down running rich ... I finally caught it one day while playing with the throttle in the garage... later when I took the AFM out, and played with it by hand, I could see how it was sticking occasionally at the top end, ie. open.... yours could be from sticking or dragging on the low end.... I did some repair to it, but not trusting it, I set it aside as a spare and put in a backup AFM I got from someone for free.

Take the AFM off and play with the door and check resistance out as others suggested... you will learn a lot in the process. Keep the BFH in the drawer for now. If you are adventurous, pop the lid off the AFM and have a look at the mechanism inside... just reseal with a bit of RTV.

- Dave

Maybe your distributor centrifugal advance is sticking at idle
position until you get enough rpms for it to break loose. No, maybe that's not it. Perhaps your vacuum advance diapham
in leaking, not giving you the ignition advance you need off the line.

Just thoughts.

Phil