Hi guys,
I am just new to the forum and intend to spend lots of time going thro the various threads....

I have a 4x4 Sapphire from new in july 1992 and recently it has started to cut out when i floor the throttle.It runs perfectly at idle or even 80 mph on motorways. If I accelerate "gently" it will go right up the rev range but when I floor it the engine just cuts out as if I have turned off ignition (rev counter stll remains at current rev). After a split second it starts again.If I continue holding down the throttle it stops/starts and jumps violently.

Any help will be most greatly appreciated.

 

I'm no expert but sounds as if its blowing the spark out, have you tried new leads and plugs

 

I agree with bpspa, that is the first thing I would do, plugs and leads.
Gap at 0.65mm, and use decent plugs and leads like Magnecore, plus a group a coil, just for a bit better spark.
tabetha

 

Could also be the boost limit kicking in.
What boost do you have currently with gently acceleration and what's the reading when you floor the throttle?
Is it chipped or not? When chipped what level of boost are you supposed to have?

 

Many thanks for this. Will will get new plugs and leads this weekend and fit them. Will let you know how I get on . It seems really odd because I never thought of plugs/ leads as this is not a misfire at all. Its just like I switched the engine off and back on again real quick. That would mimick the exact problem that I have.

 

It is chipped; stage 1. I put the old chip back in to test with the same result. I do not have facility to check boosts but if leads/ plugs do not sort it out I will turn my attention to boost. Someone else has told me to change the fuel filter but I really do not think it is the filter??

 

There is a faint possibility it could be the filter, though I don't think so, but if not changed within the last year I would do this anyway, check pump voltage at the same time, under load.
tabetha

 

check the pipes that come from the turbo to the amal valve sounds as if its hitting the boost cut off.

 

got a similar problem on mine, would love to know the answer!

 

has your petrol tank got a swirl pot ?? try filling the tank half full..then boot the car see what happens

i only run my car on a half a full tank...as i have no swirl pot in the tank

needs to be upgraded

 

Guys,
I have fitted the new fuel filter, new plugs (Motorcraft AGPR 902P) and leads and the fault is still there. The engine just stops on the way up. My gut feeling is maybe the boost as Ians2RST and oldford have indicated.
Not knowing too much aboiut the boost can you tell me what to look at? Where is the boost unit anyway? And can I just turn back the boost w/out using a guage just to see if it stops the engine completely cutting out??
Your help is appreciated...

 

17-APG do you have a so-called "ämal" valve? This is an electrically controlled brown valve normally placed on the right hand side of the intercooler. It has 3 connections for air hoses and an electrical connection. Disconnect the electrics. Now your engine should run with low boost and should not reach the boost limit. Just try it on the road and see if the engine cuts out. You should feel a substantial loss of power, but this is normal, because the boost is a lot lower now.

 

Yes I believe there is oldford. There is a small round plastic valve positioned to the left side of and on top of the intercooler quite close to the actuator ( as you stand and look at engine bay). This valve has a brown centre with a number of air pipes and an electrical connection on top ( from memory maybe 3 point connection). I will remove this and run road test to see what happens at weekend....

 

Not sure on swirl pot, I dont think so but what I do know is the problem exists whether i have just a few litres in the tank, 50% full or full. I really believe my problem lies with tirbo. The engine just stops under hard acceleration; it doesnt splutter or misfire it's just " lights out" for a second and then fires up again.