Loss of power at 55- 60mph

After travelling for about 20 mins and on the motorway there has been a loss of power , this has happend on a few trips .but is intermitent , Acceleration up to 60 for short bursts is ok but the steady speed causes loss of power , this morning while on the way to southport it happend again so i pulled of on to a slip road , the fuel pump made a noise for a few seconds , it never stalled and was fine coming back about 10 miles ,

2ltr type 4 engine

The fuel pump is nearly a year old ( electric pump )

The coil i replaced in November

i think the pump runs of the coil



any ideas

 

There was a thread on this some time ago. IIRC you need to get your pump power from somewhere other than the coil. Maybe it's own relay switched fused supply from the starter connection with a feed from the blue regulator wire to trip the coil so engine stops, pump stops whether ignition on or not.

 

Either that or it's overheating a seizing...

 

just had look at it , it is wired from the starter and there is a relay

 

Can we assume it's not petrol starvation then (though it still might be)?
Check the timing next (full advance).
Then look for air leaks that could result in overheating? - manifolds, carbs, connecting pipes, servo vacuum pipes.

 

shes due for service soon so i might bring it forward or at least check it over for leaks and check the timing . also i might invest in a dwell meter .
i have just had a look at the bently manual they suggest
1 fuel starvation at driving speeds
2 low fuel pressure
3 dirt in fuel system
4 low level in float bowl

 

Yep, could just be a clogged filter or dirt in the carbs. Does it always do this or does it sometimes drive fine?

 

Reading your first post again about being ok for short bursts, I'll put my money on your timing being a few degrees too advanced and overheating. We'll see when you get it back from the garage. I agree you should do it sooner rather than later just in case it's something that could cause damage. Probably not, but better safe than sorry.

 

Check the wires and terminations to your coil, mine when i first got it had one termination connected by only 2 or 3 strands and ran for a while but then things got hot and stopped, 10 mins to cool and all well again!

Does this sound similar?

 

I'd say overheating.

 

I just had this problem discovered my tank was full of rust so out it all came bought a por15 kit resealed the tank and running a treat.

 

So today i set about the beast and gave her a service the timing was a couple of degrees out a couple of valves were a little bit out , i changed the fuel filters x 2 ,air filter . checked for loose or missing hoses , replaced a dodgy choke wire connection put in new plugs the old ones were a bit sooty ,( setting the mixture is a bit beyond my ability , so im thinking the rolling road is the way forward with this ) changed the oil/ filter .

first job in the morning is to go for a blast up the motorway and see if there is any difference

 

Setting the mixture won't effect top speed as it's the idle circuit. Air leaks will big time. Check for a loose carb/manifold/head nut.

 

checked carbs are bolted down and i will look for manifold loosness in the morning

 

Same happens to me worth checking.

 

Just out of interest, why do you have two fuel filters?

 

My 1700 type 4 doing the same I'm going to try replacing the fuel pump pushrod as on new manual fuel pump and its like fuel starvation. If it was overheating I think it would have done some serious damage to bores by now you would think

 

One before and one after the pump ( electric pump ) I have looked in the tank and 1st immpressions are it looks ok

 

I see, I take it that is common practice for electric pump installs? I have the same engine and started to wonder!

 

power loss at 60? if my bus ever gets to 60 it'll be a bloody miracle!!