petermcg

My dodge 440 is in a 6 ton motor home with a 727 trans. It starts reluctently and then has no power when shifted into drive It will crawl forward about 1mph for a few metres then cuts out. It may be slightly better when cold and gets worse as things warm up. It has an electronic ignition. Carb rebuilt, new mechanical fuel pump. I took it for a drive, it run a bit for a while, I went to garage and fueled up and it was much worse, very hard to start and would only crawl. I played with it for about 1/2 HR and finally got it to move starting off very slow and building up enough speed to get home.
This problem has existed for quite some time now.
I have tried electric fuel pump, different electronic module, different coil. So I think it might be the timing chain has jumped, but how do I check that, I dont think it will start now.
I set no 1 so the rockers were loose and the valves closed, the rotor was then pointing to the no 1 cyl on the cap. But at this point the mark on the crank pulley is about 3/4 to 1 inch away from the tdc. I just need to confirm that it is worth looking at the chain as it is an akward job on a motor home. Any Ideas?

Coronet 500

Welcome.

Take a wrench and move the crankshaft back and forth against the resistance of the valve train. Crank movement of 5-10 degrees is acceptable, 15 or over is too loose.

If the chain is ok and the balancer has slipped maybe the last time it was timed with a timing light was wrong.

petermcg

I now cant get the engine to fire, and run, I did get 1 backfire, I have spark and fuel, but unsure of the cam timing. Engine has only done 49000 miles, there does not appear to be much play when I rock the crank, so chain is probably OK but still not convinced about the timing, any Ideas.What is the best method to check if cam and valve timing is correct or not.

EDIT compression test done 70psi up to 100psi, plenty of fuel dripping from plug hole and has spark.

Skwerly

sure sounds like it could be a timing issue.

RacerHog

In my book 70-100 are to low of numbers (125)..... With what you have described... If all that is correct. What i red is that you need to open up the front and make sure it has moved time on the chain. From what you stated I dont see it jumping time at all. But when you say the dist is not lining up and also the crank is not lining up with the mark. Ether something has moved or you just not doing it correctly?

Pull the valve cover for the number one side.... Roll the crank over to DTC on number 1 Compression.... Making sure the rockers follow.... And make sure the damper sets on 0 @ TDC.... If the all this lines up ok to this point. Reset the dist and see if it starts... If it starts look at all the rockers and see if they are all moving about the same amount up and down. It so. you should be good to go... if not, may have to dig deeper. Make sure the exhaust is not restricted...
Hope this helps Keep us posted..

petermcg

Since the compression test,which I did wrong, (throttle was open but the choke was closed),, I have come to realise that the carbutetor is flooding bad and has been for quite some time, probably since the carb was rebuilt. I think there was a lot of fuel in the sump. I removed the carb and found that allthough the needle and sets where working, there was a leak from the threaded part of the seat on one side, there is a copper seal under these and they dont seem to be thick enough for the new seat to seal. I replaced these with a rubber o ring from the carb kit and managed to solve that problem, I checked the float levels as close as I could and remedied another couple of problems in the carb. With new oil the engine is running and idling well, I think with no flooding. I need to do some more test drives to be sure. I reset the distribrutor timing with some advance. when I done the rocking test..

I still am unsure if my cam valve timing is correct but would presume it to be OK as the engine is low miles and there did not seem to be any slack when I done the rocking test.

Skwerly

keep in mind, valve adjustment and cam timing are not the same thing. glad you are finding culprits!

RacerHog

Glad you found the flooding issue... Much easier to fix... Keep chipping at it....

petermcg

I am sure I have the flooding sorted out, Starts and Idles well,, will only accelerate up to about 40mph or about 2500rpm and then it stumbles and missfires a bit, I dont know what this is, could it be float levels?

RacerHog

I dont think thats going to be it at this point.... Is the exhaust restricted ???? Bent / Plugged? Make sure it feels like it has enough flow...

petermcg

I have set the piston no 1 to TDC, lined up the thing in the dist and checked clearance with the rotor pointed to no1 plug wire. The timing will be close now. But the marks on the harmonic Balancer seem to be a bit off. Have taken for another drive and still stumbles and cuts out about 2000 to 2500 rpm. I will check the filter and lines next, I have electric fuel pump in the line with the mechanical for priming, so I dont think its the pump rod.

RacerHog

ALso Check the tailpipe and see if it feels like enough exhaust is coming out of it... Check to see if the exhaust is restricted inflow?
Sounds like you have the rest covered at this point...

petermcg

My pipes seem clear no bends or breaks, I also done a check with my vacuum gauge to check for blocked exhaust, all OK. I also have checked the timing with vacuum gauge. The vehicle starts, idles and runs good just stumbles about 2000 rpm. I need to move soon and have a journey of about 100 miles so I was hoping to do this the way it is I can travel around 40 mph. I think my distributer points to No 1 at a different place to what it used to, it seems to be advanced quite a few degrees, as well as this my Harmonic doesent land on TDC mark either, it looks well advanced but this must be because it has moved because It is now checked with the piston no 1 at TDC.

RacerHog

ok.. Try this..... Back some of the timing out..... And then reset the idle... And give it a test drive and see if it act any better? You could be rite and the balancer mite have spun... Normally you get a vibration when that happens... But, Let see if this will take care of the 200 rpm missing issue... I think what it happening is that your getting to much advance? You could try just disconnecting the Vacuum advance hose first and see if that will help and if it does then move the timing back... What ever you feel comfortable with....

petermcg

I have just read through what I have written so far. I should add that prior to the first post when the carburetor was flooding it seemed to Rev OK. But I still now have the situation after fixing the flooding problem that I cant when driving get it to rev above 2000rpm,, it will rev freely when stationary up to 3500rpm, but when under load it justd I have taken out my inline filter and have tried it on 2 fuel sources as I have 2 tanks,,oes 2000rpm and stumbles and sometimes slows down and stops,, so is it in the carb, it is a thermoqaud and I have been inside it and fitted the parts from a carb kit., I have also tried with the electric fuel pump which is in the system,, next I will remove the electric pump from the lines and see if that is restricting.Any further Ideas.

RacerHog

From the description you are giving... I would say Yes... Try a different Carb and see it that makes it better...

RacerHog

If you can get ahold of one of these to try....