# IH 674 (78bhp) Running under load issues



## Casiat (Jul 5, 2011)

Hi there from Norfolk, England.

I have had a browse through the forums tonight but am unable to find an exact answer so am posting in hope of some advice.

I have a 1977 674 with 5100 hours. I bought it to 'top' a 3 acre paddock and have owned it for 7 years without problems.

I am not massively good with mechanics but have a rough idea of the principles.

Problem started last week when cutting the grass and the engine started 'hunting' then died. I was low on fuel but not completely empty so i assumed a blocked fuel filter as I had a similar problem a few years ago.

Now having changed the filters it took almost 12 hours for the fuel to feed its way back, however the Tractor eventually started but would not rev - again it would start hunting, cough and die with a burst of black smoke.

I could see bubbles in the moisture traps and each time it stalled, I could release air via the bleed screw.

I let it idle for ages and then having cleaned the air filter as well it started and seemd to run ok at higher reves and even let me lift the topper up on the hydraulics.

So I gave her a run and all was well for 3/4 hr until she started hunting again. This carried in again and eventually got worse and stalled.

I was then back to square 1 - starting fine but at high reves or lifting the topper she would start hunting for about 10 seconds and die...however always restarting fairly easily.

Throughout I have seen bubbles in the bowl, however I am not now getting air released via the bleed screw.

I have tried loosening each injector in turn and fuel seems to flow ok.

The only thing I found tonight was an old brittle pipe running between some of the return pipes and what appears to be a switch with an electrical connector on the left side of the cyclider head. I have replaced this, however the fuel in the old one could be seen and had massive air bubbles in it.

uSo is it air on the injection side, air on the return side, a broken or worn injector pump or another problem I haven;t considered. Any advice greatly welcome as I might need to get some sheep in to keep the grass down soon....

Cheers

Athers


----------



## rsmith335 (Jun 2, 2010)

I think you are on the right track, I would replace all the tubing and clamp with good clamps.


----------



## farmertim (Dec 1, 2010)

Welcome to the forum casiat, you might have sucked something into the fuel lines, Maybe try to blow back through to ensure all is clear
Cheers
:aussie:


----------



## cyrush (Apr 20, 2010)

To save copying it all out again !! read my post's here http://www.tractorforum.com/f48/ih-484-will-not-start-17578/


----------



## Casiat (Jul 5, 2011)

Thanks everyone for the replies so far - Cyrush - that is a good thread with lots of good info. I wish I had blown some of the lines through when I changed the filters. I should have thought about 474/574 for similar threads.

I am still convinced it is air - I can still see small bubbles in the traps when running and it invariably has trapped air when I open the bleed screw after it stalls..

It is possible I suppose that there is a hole in the line to the filters or the tap in the tank is partially blocked causing air to come down the line.

It always starts first time everytime and idles fine....until you load it.

HOWEVER it is getting better....I was able to run it tonight just above idle and it would lift the topper and turn the PTO without stalling....although lift the reves above 1000 and it coughs splutters and dies (still starting immediately again)

I am going to remove and reseat the filters again and pop the taps off to see if there is any crud in them.

It is going to be trial and error I think. Wish I could take a week olff work to sort it....


----------



## cyrush (Apr 20, 2010)

Any holes in metal compnents allowing air to be drawn in will show external signs of moisture (moist fuel residue) but on hose joints you can get situation where air can leak in but it is difficult / impossible to see an external leak.

SUSPECT ANY RUBBER HOSE JOINTS AND RUBBER HOSE THAT IS AGED.

Inspect the filter heads very carefully, they are made from cast alloy (Monkey metal ??) and sometimes there can be porosities in them that start to leak or let air in after a time. they seem to work ok for first few years of life !!!


----------



## Casiat (Jul 5, 2011)

Cured!!!

Haven't had a chance to do anything because of work commitments - but a rainy day at home gave me a spare hour.

I took off the fuel pipe after the filters and was convinced there just wasn't enough fuel.

Removed the most rearward tap on the offside of the fuel tank (connecting the balance pipe) and the fuel gushed out.

Did the same at the inner tap (last in line for filters) and nothing but a dribble.

Screwdriver up the hole and 'eventually' out came the fuel.

There was a real caked up deposit in there and loads of crud came out.

Reconnected and started her up and low and behold an instant cure.

It seems so obvious doesn't it! I could be cross for not checking weeks ago, however I am just glad the old girl is up and running again.

To celebrate I cut 1/2 mile of local bridelway that was knee deep in nettles - that should satisy the locals who had to put up with hours of bellowing and coughing tractor over the last few weeks!!

Thanks for all the help!

Athers


----------



## cyrush (Apr 20, 2010)

Glad to have been of help. Know the area you are in well, used to work with JOHNSON Bros, FRAMLINGHAM TRACTORS & SUFFOLK AGRICENTRE, on a regular basis.!!!!


----------



## Casiat (Jul 5, 2011)

cyrush said:


> Glad to have been of help. Know the area you are in well, used to work with JOHNSON Bros, FRAMLINGHAM TRACTORS & SUFFOLK AGRICENTRE, on a regular basis.!!!!


The Agricentre is quite close to me.

There is a place I have just discovered in Attleborough itself that I was going to call if I hadn't sorted the problem.

Whilst they deal with some big modern stuff, I saw a Fergie and an old MF outside, so I assume they take anything on!


----------

