Running problem
Discussion
Just got the girl back on the road after changing heads and manifolds.
Now for some reason at low speed in a higher gear it shudders and kangaroo's, example 4/5th gear at 30 mph. i have to be in 2nd or just 3rd.
It idles absolutely fine and when foot down its fine, it seems a little slower than it used to but that could just be the heads.
any ideas guys?? bearing in mind I moved 3 days ago and absolutely broke lol.
Now for some reason at low speed in a higher gear it shudders and kangaroo's, example 4/5th gear at 30 mph. i have to be in 2nd or just 3rd.
It idles absolutely fine and when foot down its fine, it seems a little slower than it used to but that could just be the heads.
any ideas guys?? bearing in mind I moved 3 days ago and absolutely broke lol.
GreenV8S said:
james280779 said:
example 4/5th gear at 30 mph. i have to be in 2nd or just 3rd.
You're labouring the engine, stop it! 
I'd check for inlet air leaks and chech that all vacuum pipes are fitted. The other thing is that I assume you removed the distributor. In which case is it timed up properly? Don't know the 2.8 but if it is anything like the 2.9 then you need to set it into service mode before setting the timing.
Edit: Forgot that I had a Haynes manual for the 2.8 until after I posted the above. Mo service mode for the 2.8, just need to remove the vacuum pipe when setting the timing.
Edited by Jed-S on Monday 30th July 21:05
It does sound as if it is drawing air somewhere. Try checking all of the vaccuum pipes as suggested.
Other possibilities, seeing as you say you have just changed the heads, are manifold - the inlet manifold to be precise - is it seated right? the V-shaped gasket can be difficult to get a good seal on, and if that is drawing air you may need to refit the manifold.
It could be an air leak anywhere in the intake system upstream of the air flow meters - the intake hoses, the throttle spindles, the plenum chamber are all possible candidates. It could even be drawing air past the valve seats (although then it would be drawing oil too and you would see the smoke when you accelerated after a period on over-run)
Can you maybe borrow a vaccuum gauge and fit it say to the brake servo connection? That will give a good indication if vaccuum is low - it should be about 20 to 22 inches of mercury on a well-running engine at idle. You can also tell a lot from the behaviour of the vaccuum needle, although that is too detailed to go into here! Gunsons (I think) sell a diagnostic one that comes with a wee leaflet that tells you how to use it to diagnose everything from broken piston rings to worn valves etc. Mine is older than I am, and I ain't no spring chicken, but it still works (which is more than can be said for me).
Other possibilities, seeing as you say you have just changed the heads, are manifold - the inlet manifold to be precise - is it seated right? the V-shaped gasket can be difficult to get a good seal on, and if that is drawing air you may need to refit the manifold.
It could be an air leak anywhere in the intake system upstream of the air flow meters - the intake hoses, the throttle spindles, the plenum chamber are all possible candidates. It could even be drawing air past the valve seats (although then it would be drawing oil too and you would see the smoke when you accelerated after a period on over-run)
Can you maybe borrow a vaccuum gauge and fit it say to the brake servo connection? That will give a good indication if vaccuum is low - it should be about 20 to 22 inches of mercury on a well-running engine at idle. You can also tell a lot from the behaviour of the vaccuum needle, although that is too detailed to go into here! Gunsons (I think) sell a diagnostic one that comes with a wee leaflet that tells you how to use it to diagnose everything from broken piston rings to worn valves etc. Mine is older than I am, and I ain't no spring chicken, but it still works (which is more than can be said for me).
Work out for yourself how safe you think this is but I'm sure someone said to squirt lighter fuel (gas I think) around the inlet manifold, plenum etc and if you find the leak the revs will increase.
The problem you may have is that the leak may not be apparent until the engine is under load.
I've never tried this so have no idea if it works or not.
Also not sure how you get the lighter fuel to come out without getting frostbite in your fingers!
Chris
The problem you may have is that the leak may not be apparent until the engine is under load.
I've never tried this so have no idea if it works or not.
Also not sure how you get the lighter fuel to come out without getting frostbite in your fingers!
Chris
Barkychoc said:
Work out for yourself how safe you think this is but I'm sure someone said to squirt lighter fuel (gas I think) around the inlet manifold,
I think you'll find that it is butane gas and not lighter fluid. Use a blow torch but don't light it 
I've never tried it myself but have heard this from several mechanics.Jed-S said:
Barkychoc said:
Work out for yourself how safe you think this is but I'm sure someone said to squirt lighter fuel (gas I think) around the inlet manifold,
I think you'll find that it is butane gas and not lighter fluid. Use a blow torch but don't light it I've never tried it myself but have heard this from several mechanics.Gassing Station | S Series | Top of Page | What's New | My Stuff