Engine hesitation-4 carB talk!

[cth350]

Chuck, are you referring to the linkage from the accelerator pedal? That's only going to affect the delay between touching the gas and start of opening the throttle plate, and not how wide the throttle will open (unless it's severly screwed up). A cursory glance seems to show that spacing to be the requisite half inch or so of travel. [I was giving Christy & her dad phone support last night :].

I felt, at that point that one of two things is wrong, either the accelerator pedal is way out of wack, or the linkages on each carb going to the throttle plates are way out of wack.

I asked Christy to get a measure of the engine speed when it seems to be "idling normally". Since she's working inside the garage and doesn't know what 800 rpms "sounds like", a read off a tach is in order to have a hard number.

The other test to make (and I forgot to mention this on the phone, sorry), is to look down the throat of the carb with a flashlight as the engine is idling and make sure that there isn't gas pouring out of the whatchamacallits sitting in the middle of the carb. You know, the tidbits you cleaned & reinstalled last week.

-CTH

[bachlauter]

Guys...

Ok. Y'know how one must adjust a clutch cable to the right length...too short won't work...too long won't work. My problem seems to me, to be the gas pedal adjustment...if there is such a thing.
What I am trying to say, is that I NEED the gas pedal to DO MORE, while being depressed LESS.
Does that even make sense? My gas pedal will only DO ANYTHING when it is FLOORED.

When I talked to you, Charlie, I'm not sure if I was measuring the right thing. Did you mean the little part that stretches a centimeter or so, BEFORE the entire linkage moves??

What I think the car needs is something a little more MAJOR than the idle speed adjusting screw. I could be wrong...I HOPE I'm wrong, but something is wact and it may be more than one thing.
I know the PO messed with the fuel pump...it can be adjusted, right?
AND those brass nozzles AREN'T shooting ***** into the venturi..the rear one drips one or two drops a minute...NO steady stream happening here! I'm CONVINCED the pump pistons are busted! (accelerator pumps?....are they supposed to be continuously shooting gas down the throats??)

It is SOOOOOOO VERY CLOSE!!!! (I think!)

~Christy

[cth350]

You should only see fuel coming out of the preatomizers (I looked it up) when you're off idle and running. So at an 800 rpm idle, you won't see anything, but 1,000 rpm you will.

So, so far, your observations lead us to believe that you have to really move the pedal a lot to get a small opening at the trottle. Once you can confirm that you're not going past 1,000 rpm when floored, we'll no for sure.

I'm thinking that you need an assistant again. With the assistant flooring it, watch the throttle linkage. while the assistant holds the pedal to the floor, move the linkage by hand. Is there room to go? and if so, how far?

Do this first with the car not running, just so that you get a feel for it. There shouldn't be a lot of travel available for you to play with beyond the pedal's full range of motion.

Try the same test with the car running. Be prepared for one really loud backfire. Also, when you bring the linkage back to rest (with the assistant still holding the pedal), don't be surprised if it stalls.

Be sure to do that last test with the tach connected. If there is freedom to move the linkage beyond the pedal's travel, accelerate slowly to 3,000 RPM in 200 RPM increments, get the engine to stay at each speed for about 5 seconds w/o having to wiggle the linkage. I would be curious to know at what speeds it seems stable and at what speeds it tends the meter wiggles or the engine stumbles. Of course, I'm making a big guess that the current problem is the pedal linkage.

-CTH

[bachlauter]

HI!

As I pressed the pedal on one of the times we had it running, my Dad pulled the linkage back a bit (not THAT much) FARTHER, and it DID cause the car to stall and backfire! My Dad was just being experimental and all this sudden action was somewhat startling to him! He apaologized profusely but, he KNOWS I don't care!

So, what do ya think? Pedal linkage? Did it stall because my pump pistons don't work?? BTW Chuck, I DID take the nozzles out and found there to be NO blockage. I BLEW on the underside HOLES, with the screws removed, of course, UNDER the pump and beside, and air travels through the nozzle freely...so I've got bad PUMPS, huh.

Nothing like a girl working on a car with a pair of BAD PUMPS...

~Christy

[ctaylor738]

Christy -

I think that your first step should be to get the car to idle and then increase in RPM when you gradually increase the throttle. Once you get there, you can sync the carbs and eliminate them as a source of trouble.

Remember, you only need the shot from the tube when you increase throttle quickly. Like Charlie said, the accelerator pumps will not affect idle and constant speed.

Suggest the following:

1. Measure the distance between the accelerator pedal and the floor, at the top of the pedal. It should be three inches more or less. If it is not, then you need to figure out why. My bet is on the "bellcrank" under the front carb which is formed by two pieces of metal joined by a screw. I think that one can loosen the screw and move the two pieces to obtain the proper clearance between the pedal and the floor.

2. Have someone depress the pedal slowly while you watch the carb linkage. First, the quarter inch of slack should be taken up in the "slider" on the linkage. THEN, BECAUSE OF THE CONNECTING ROD (AT THE BOTTOM), BOTH CARBS SHOULD START TO OPEN. When the pedal is fully depressed, the primary throttle plates should be fully open as in verical in the throttle bores. You will have to look down the bores with a light.

3. Remove the connecting rod between the carbs. Adjust the throttles with the adjusters at the rear of the carbs until the top levers are about one-quarter inch below the flat surface from which the idle stops protrude. It is important that the levers be in the same relative position. Now put the connecting rod back on. Adjust the length so that the carb levers are not disturbed when you put it back on.

4. Give the throttle three good pumps, hold the throttle slightly open and start the engine. Once it fires, bring it slowly up to a fast idle and let it warm up.

5. Back off on the throttle and let the engine idle. If it will not idle, adjust one of the idle stops (on the underside of the cover) to increase or decrease idle speed as needed.

6. When you get it to idle, you can sync the carbs like the manual says. Then deal with the bad pumps.

If the engine does not start and run, then I suspect that you have fuel supply or fuel pump problems. Also remember that it has at least one dead cylinder, so it is not going to purr.

Chuck

[cth350]

Christy,

Let me alter Chucks instructions a little...

Start with last half of Step 2... With the pedal floored (assistant or a cinderblock), look down the throat of BOTH carbs and make sure that the throttle plate is up. [Good call on that Chuck, I was trying to think of how to check them, and was thinking about how closed they were, not how open.]

THEN, disconnect the linkage from the pedal to the front carb. BEFORE you do so, note the relative position of things. What we are trying to discover, is if the range of motion for the carb linkage is being restricted by any other component.

Can the throttles move better when the accelerator linkage is disconnected? If so, try to explain it to us, either that they can open more, or they can close more.

Can the throttles move better when the linkage between the two carbs are disconnected? If so, which carb has a greater range?

Most importantly, how fast is that idle? I presume you haven't had a chance to get the RPM rate w/o your dad being around.

-CTH

PS. Keep up the good work your work last night was good!

[bachlauter]

Guys..

I CAN'T increase the RPM...the engine will NOT rev...It doesn't make sense!!

Dad's coming over tomorrow...I will have some hard (rpm) numbers for you guys..

Meanwhile...last night I adjusted all of the linkage to the carbs....y'know the rod with the slider on it...I made it so that it would open the throttle more, sooner....it really didn't seem to help..

Note: Remember...I DON'T know what I'm doing!!!!!

WHY is it IMPOSSIBLE to rev the engine??? Lack of fuel?? Could it be some wacky electronic rpm switch??? It CAN'T be ignition, right???

~Christy

I wouldn't eliminate the timing from the equation. I don't know why, but before I took the carbs off I could set the idle when the car was hot, have it idling sweet, close the hood put my feet up open a KLB and pat myself on the back. However, when I wake up to go to the gym in the morning, it sounded alot like the condition you describe, mat the pedal to hold idle. So I turn the distributor CW a hair or 3 and I get my idle back, and I'm down the road fuming I haven't beaten the rush.

I'm not saying it is your problem but I wouldn't dismiss it outright either.

PS
Love those Pens!

[bachlauter]

Guys..

How free is all of this linkage supposed to be?? What I mean is, that when I got this car, all this linkage was soooooooo gunky that it didn't move very well. NOW it is sooooo clean, that it's sort of STIFF .

The amount of movement the linkage will do BEYOND what the gas pedal will make it do, isn't enough to matter, at least I wouldn't think. It will only open the throttle a touch more...

On another thread I mentioned the TIT...on the fuel return valve, being constantly pressed in. What the hell would that mean?? FUEL STARVATION????????????????????????????
Aka: MY PROBLEM????????????????????????

~Christy

[cth350]

The fuel return valve is that bronze button screwed into the front carb. On its bottom is a small silver button. The pedal linkages are designed so that the valve is closed as soon as you touch the gas. Otherwise, at idle, the valve is open and fuel circulates back to the tank.

The guy on the other thread is getting starvation at speed, not idle. The fuel supply at idle is sufficient to keep the bowl filled AND allow for the circulation of gas back to the tank. At speed, there isn't enough gas to do both, so they close the valve.

-CTH

[bachlauter]

Hi guys.....

I don't know what the hell happened....but my car won't even start now. It started the first try, ran for several seconds and choked out and died. The DIFFERENCE this time is that it will not start again. It cranks fine, seems to be firing, but no go...

We did discover that the points are bad. However, My distributor has an ERECT SHAFT inside of it and the points have a HOLE through one end that SLIDES ONTO THE SHAFT. The local auto store had no set of points (in stock OR for order) that even resembled my points. My distributor number is 114xxxxxxx so I think it is original to the car...all the points they had for sale had a rivited part (instead of a hole) on the "hinge" side of the points..
So...we filed my points to try to make them temporarily work, but we cannot get a decent dwell number unless we make the gap non-existent.

As for RPM...no can do...the highest rpm I could get while cranking was 400rpm...but the car wouldn't start..

Speaking of starting...that is partly the problem...the car cannot get a high enough rpm...it's just bazaar!! Even when it DID start, it idled so quietly and I couldn't rev the engine or raise the rpms...

I removed the fuel lines to the carbs...took off the center coil wire and cranked....gas spurted out of both lines evenly...cranking it for say, 2 seconds, resulted in 3-4 tablespoons of gas in two little containers..seemed ok to me.

The problem seems to be a lack of fuel...

About the gas pedal...I can start to depress it maybe 3/4 of an inch and it does NOTHING. It'll go down about 1 1/2 inches to the floor and it moves the linkage on the carbs back...however, the linkage still has about 3/4 of an inch to go back AFTER the peedal is fully depressed...
ALSO, tried to fool with that return valve....it didn't help...I moved the blades both below the acentuator so it sort of works better, but it is the only thing I changed and now the car won't start...the car did better with that TIT pushed in...hhhmmmmmmm

I am really screwed here. I know that replacing those points isn't going to make the car start. It might help, but I'm certain that they are not the problem.

I'm so bummed..the car won't start at all now!!!

~Christy

btw...I realized that the distributor number is completely different than what I had said above...but does it matter???

When I try to crank it...it won't even come close to starting and when I stick my finger in the primaries, they are all wet and have gas all over them...the point being, that I think that the engine IS getting gas....BUT it doesn't smell like gas after cranking and the plugs aren't wet...I AM getting spark and dwell is around 35...battery IS charged...compression should be good enough.....I'm soooo discouraged!!!!! I tried to make the mixture leaner..it didn't matter. I'm LOST!!!!


[Edited by bachlauter on 05-12-2001 at 08:09 PM]

[cth350]

Christy,

"there, there dear". OK, so much for patronizing....

The distributor number should be 0 231 116 052. I just checked some vintage bosche points, I have about 50 that are marked for your car (67-69 model 250) and sure enough, they all have the stud. So, see if your distributor number matches the one I wrote above.

Do you know if your points are any worse than they were when you first got the car? I presume they sucked then too. That's GOOD news, since a new set of points may make a big difference. Your plugging that vacuum leak to the brakes will also help.

-CTH

[bachlauter]

CTH....

That IS my distributor number!!!

The points have been like this ever since I got the car. They are very worn....do you think it'd make that much of a difference???
We couldn't tell how worn they were by looking, but we got real brave and revoved them from the distributor...and....WOW, who'd have thought! I NEED new points! Currently (no pun!) the contacts aren't flat and do not make a perfect contact. So...

~Christy

[ctaylor738]

While you are in ignition land, you might consider plug wires. I got my biggest single "gain" on the 280S when I replaced two bad wires. That got it to the point where I could work with the Zeniths to get it to sort of idle.

Hang in there!

And happy Mothers' Day!

Chuck

[cth350]

Christy,

I'm gonna send you a care package on Monday. In it will be a suitable pair of points (which I just happen to have laying about in NOS condition) and the book I've been sending you excerpts from.

Do you need another tool like the last one? I know you've put it to such good use.

I'd send you my unison, but Mitch has it.

-CTH

PS. New plug wires WOULD be a good idea, but you don't want to know what they cost. Since nothing but the real Bosch ones will do.