Engine dies when going into drive.. please help

I've been trying to help my friend get his truck going for the roundup for quite some time. Here's what it is..

'56 F-100
'75 Chrysler 440 Edelbrock 1405, Edelbrock Torquer 440.
727 Torqueflite
caprice clip

Basically it is a collection of random makes and models that looks like a '56 ford P/U

We've been struggling with it for a while. The engine is at least partially rebuilt. The heads were redone, but that's about all we know. It seems to have a big cam in it as well, be we don't know any specifics on it.

Ever since he got it it has had a problem with idling while in gear. Requiring you to keep your foot in the gas to keep it alive.. Problem is, is that it is not weak and keeping your foot in it a little will push the truck forward.

So here's what we've done so far and fixed so far..

Changed carbs, 2 times. Both would not Idle in gear, carbs weren't that great and had their own problems

Rebuild the original Edelbrock 1405, found that the Choke spring had been put in backwards and was closing the choke after warming up. Fixed that and fixed a starting problem it had.

Found that it did not have the +12V wire for starting to the coil, only the wire through the balast. Fixed it and is also seemed to help starting.

Checked for air leaks and found none.

Found several bad grounds (including bad batt cable) Fixed all of those, and fixed the no intermediate no power problem.

Once the carb was rebuilt we were able to time it. We first timed it the normal way at idle (although idle is a bit lumpy) to 8 degrees and it idled great and had great response. At the suggestion of a race mechanic we timed it again at 3krpm for full advance of 25 degrees( without the vaccuum adv.). Seems to run worse like this and is harder to start. Full advance the other way was 33 degrees. With full advance at 25 it also stumbles when you get on it, and is weak on power.

So I am going to time it back to 8 degrees at idle. after that it should run great, idle great, and have good throttle response when out of gear like it did before. I didn't get a chance to drive it like that before so not sure on the power. one thing that is not fixed is the kickdown lever is not attached. I don't know which way it is supposed to be pulled under WOT.

The problem we have had all along is that it still dies when going into drive. Even with the idle screw in and the idle being around 1k it will die. It feels like the trans is putting a big load on the engine when it goes into gear. But I've read that 727s had a habit of not filling the torque converter enough.. so that would be the opposite problem.

Is this just the penance you pay for a big cam? It doesn't feel like it has any other stall than a stock converter. Do I just need to jack up the idle until it will stay running?

 

What kind of distributor are you running? I had a very similar problem with my Pontiac wagon; motor timed well, sounded strong and everytime I would put it in gear, it died. Finally figured out that the HEI distributor (high voltage etc..) HAS to have constant 12v to run. If voltage dropped below 11 volts, as it did when in gear, it died. I ran a dedicated 12v line from the ignition switch to the disty and problem solved. I realize that HEI is GM, but check the specs on whatever disty you are running. Hope this helps.

51Fourdoor

 

is it shutting down like you shut it off? (Ie..switch) or is it like it will not take on the load of the trans and quickly loads the motor down?

 

It is a factory Chrysler electronic ignition. I checked all the voltages to it and had to fix a few things but I think it is correct now. The diagram I found still showed it using a balast in line to the coil.

It is bogging down like it can't take the load. it will try and it will stumble for a short time then it kills it.

 

did the trans rotate freely before you hooked it to the engine?

 

just for shits and giggles seperate the trans from the engine..or at least take the flex plate bolts out of the fly wheel to the torque converter and see if thats your load. be sure there is enough room between the flex plate and torque converter before you try to fire it back up.

 

Sound like to me in my uneducated guess is that you need a converter with more stall with that hefty cam you have. You might find out what cam you have and then find out how much stall you need with the specific cam you have. You'll get it. See you at Roundup!

 

thats a possibility i guess..im thinking you might have a locked up trans or fluid passages that are making the trans act like its locked up between rev. and 1st or the converter is stuck..just shooting from the hip

 

Sounds like your carb enrichment circuit is opening to soon due to low manifold vacum caused by the cam. Install weaker srings on the metering rods. Or you can remove the metering rod covers in the top of the carb and start it up and watch them. They should pull down into the bores and stay there. I'm guessing that they are sliding up and creating an overly rich mixture, and stalling it out when you load it up by putting it in gear. -Mike

 

dont forget about us..inquiring minds want to know ..what you find that is..

 

Thanks for all the suggestions..

Von Rigg - not sure if it rotated freely before, we didn't put this assembly together. I'll remove the bolts and see what happens.

Throttlein - You might be right, that is also what the machinist said next door.

BigMike - I will definitely try that. It does seem to run rich most of the time.

 

most large cams say right on the box that it requires at least x amount stall
to operate normally you can pull the valve cover install a dile indicater mark
your crank turn engine over get an idea of cam lift and duration then look on
any major cam manufactures web sight and get a idea for stall size needed
or you could allways just install a manual trans good luck

 

Move your vacuum advance signal from "manifold" to "ported" on the carb. (The port ABOVE the throttle plates) This will maintain your advance setting when you put it into gear. Your idle speed will not change due to retarding the advance at lower speed.

 

The big cam along with the stock converter is probably the culprit. You might try the following for a quick fix.

1. The timing on the engine is still a little slow. Most big-blocks will want between 34-38 degrees total timing. Again rev the engine to 3k rpms and set timing to 36 degrees to begin with;

2. Adjust the idle to acceptable level out of gear. This will be dictated by the cam and compression ratio of the motor. Hopefully you will be able to set at about 800-1000rpms. Check the idle fuel adjustment screws at this point. 1.5 turns +/- 0.5 turn out from the seat should provide the smoothest idle and result in the highest manifold reading vacuum reading.

Put the truck into gear. If the converter pulls the engine rpms down and it dies, adjust the idle so that the engine continues to run in gear (be sure to have a buddy hold the brake when you do this). Once adjusted to idle in gear, check that the idle transfer slots in each primary barrel of the carburetor are not uncovered. This is a small slot located just above the throttle butterfly when seated.

3. If it is still covered, that will be about the best it will get in the current configuration. If the slot is uncovered, the engine will run very rich and will act like it wants the idle fuel screws to be closed more that 1.5 turns out. If that is the case, you can drill small holes in the primary butterflies (start with 0.030" bit and work your way up). Increase the size of the hole until the idle is adjusted such that the transfer slot is covered.

4. Beyond that, you will have to play with air bleeds and that is best left to those with a more intimate knowledge of carburetors than I. Good Luck

 

I had the same problem in a car of mine turned out it was a bad valve. If nothing else maby this will help.

 

Another thing to consider, especially if you didn't install the trans. If the converter wasn't seated properly it would have hung up on the pump. This will ruin the pump and converter. It also ruins the trans. I did that ONCE, never again. This will result in the car moving slightly even in park. The converter has the ring gear on it, not like GM, so unbolting the converter will not allow you to start the engine. Also on the kick down linkage this adjust the line flow i the trans. MAKE SURE IT IS CONNECTED. A friend wanted more bang on his shifts and wired it open, shortly he had a split case from too much pressure. The kickdown linkage takes the place of a vaccum modulater used by most everybody else. Hope this helps you.




Good luck and good rodding!!!!!!!!

 

So to connect the kickdown.. should it be pulled when WOT is reached or pushed? I don't know whether to connect it to the lower part of the throttle lever or the top part.

 

Sometimes when you have a big cam, you have to crack the throttles open really far just to get it to idle.

Here's what happens:

"Often, in an anxious attempt to improve a poor idle, the idle-speed screws are adjusted and as a consequence butterflies opened – opened further than they were originally intended to be in the idle position. This causes the idle-mixture circuits to cease, or partially cease their fuel delivery within the carburetor. Now, idle fuel is being drawn through the line of least resistance, namely the increasingly exposed transfer slots, which are small slots located in the bores of the baseplate that adjoin the butterflies. The chief function of the transfer slots is not to act as idling circuits, but instead to add fuel during the carburetor’s transition from the idle-mixture circuits to the main circuits. Therefore the tuning (the positioning) of the butterflies in relation to the transfer slots must be correctly made, or symptoms of disproportion will occur: excessively rich idle, bellowing black smoke, teary eyes, and idle-mixture screws that have been rendered useless."

(from here
http://www.barrygrant.com/demon/default.aspx?page=newsarticle&Articleid=IdleEZSolve


But where I come from, people just drill a couple of small holes in the butterflies. This allows enough air in to get the thing to idle, and allows tip-in throttle to work okay too. It's kind of hit-or-miss (read the article above) but it works. But only if you've got the throttle cracked far open just to get it to idle! Good luck.

 

If you have a large cam you will need a Stall converter to let the engine idle some where around a 2000 RPM stall.A factory converter will lock up the trans at idle causing the motor to just die a way from you. I'll bet if you were to keep you foot on the gas and keep the Engine up around 1500 to 1800 hundred RPM she will stay running for you. Hope this helps you out.

 

here's a quick update..

I attached the kickdown.. hopefully correctly.

Checked the plungers as per MikeC and they are working correctly.

Reset the timing per BTmatt. better starting and throttle response.

Still dies at idle. I've cranked up the idle screw a bit and am almost at the point that it will stay running, but I bet it also has exposed the transfer slots..

I'm a bit scared to drill holes in the butterflies without actually knowing it is a big cam or some other problem.

 

Get a stall converter with more stall. I bet thats what it is.

 

Same problem when I bought my T, quick converter change and traffic is fun again.

 

We found out it was not enough convertor on the baby hemi. When we went to about 3500 stall convertor, it would idle and stay running in gear...

 

Well over the weekend I'll go out to the other shop and get the dial indicator and try to find out what the lift and duration is.. or at least a rough idea.

I put a vaccuum gage on it and out of gear at a decent idle (around 750) it had 15 inches.. Seems like plenty to me. When i blip the throttle it drops to 5..

Will a big cam still provide decent vacuum with no load?

 

It seams the only thing left is the converter

 

Had one do the same thing. It turned out to be a minor carb base gasket leak. Fixed it, ran fine.

 

A friend told me a quick check for a carb base vacuum leak is to lay a shoprag (you know the red uniform service type) over the carb airhorn while the engine is running. If the engine speed picks up, it is running lean - indicating a possible vacuum leak. Don't fold the rag, just lay it flat as a single layer over the air horn while the engine is running. Oh yeah, the rag color must be red for this trick to work properly

 

PssssT
Say Holmes.

Choo need more converter.

Big blocks are typically more forgiving when it comes to "lower" stall speeds. I would start with a 2k or 2500. 2K will be almost unnoticed...cept for the whole idles and drives nice part.

 

i second this!

 

OK, 2 really dumb questions.

Did you put the wires on with the pattern going counter-clockwise? B/RBs and small blocks take the same cap, and they are sometimes marked for the small blocks which go clockwise. This happened to me with my 383 once.

Are you SURE the timing is right? I had the same exact problem you had. My 383 wouldn't idle in gear, but would start and idle in park or neutral. I changed the timing chain and chased the problem all over. Finally I just completely disregarded the timing marks, set TDC manually (pulled #1 plug, stuck a screwdriver in the cylinder and turned the motor with a breaker bar until I felt TDC). As it turns out the balancer was off by 25 degrees. I set initial timing from there, and it has run like a song since then.

Hope that helps