i have a sierra sapphire that was converted with the 24v boa engine a couple of years ago and it has been running very under powered and i have tried numerous things and have came to the point where i dont know what else to do,

it has the egr system removed

an after market alarm fitted with engine start button on the key fob (doesnt really work that well)

has manual type 9 gearbox with lsd

modified stainless exhaust with rear silencer no other silencers

no other mods, everything else is standard, injectors, cams etc

first thing i done was changed the inline motorsport fuel filter with a new one, didnt do anything

then i changed all the air flow sensors, didnt do anything

changed the complete air manifold, didnt do anything

took the manifold off again and changed all the injectors and fuel rail including the fuel pressure thing on the rail and cheaked the wiring for injectors, didnt do anything

took the petrol tank out and cheaked pump and it was perfect and no dirt in the tank, all the fuel lines are not kinked or squashed anywhere, it is the 2.0 twincam tank with twincam pump

took the crankshaft sensor off and cleaned it, didnt do anything,

the car is running on super unleaded and recently put octane booster in it aswell incase it was shit petrol but didnt do any difference.

thought the middle silence was mabye f**ked and holding it back so took it out and put a straight pipe on it which just left the back box, very loud now but still goes shit,

all the parts i used was taken off a standard granada cosworth boa that i knew was running perfect so knew everything i took off it to try was working how it should, i bought the car with the conversion already done,

it has an lsd and escort cosworth wheels and it will spin in first but not second that well, and thats in the wet, i have 2.0 twincam sierras and they would sit with the v6 no problem thats how under powered it is, it is firing on all cylinders and i put new plugs in it when i bought it, they were just standers ones out of my local motor factors.

engine isnt smokey and has good oil pressure and doesnt heat up or pressurise, knock or rattle anywhere or choke out at the end of the road,

only other thing i can say is that when you drive it in any gear and you put your foot down it just doesnt want to pick up and go the whole way till it eventually reaches the limiter, you can nearly feel it giving a nudge now and again when you are accelerating it through the gears as if it wants to give full power but you can tell that somthing is holding it back. my standard auta granada cosworth would eat it for breakfast.

getting very pissed off with it now to the point i dont even want to drive it so if anybody on the site here has experience on these engines or any tips on things i havent tried it would be very helpful,

also i am from northern ireland and i dont know many poeople over here that knows much about them as there isnt that many of the 24v sierras as in england that i am aware of so any help is appreciated guys,

thanks for reading!

 

check your vacum pipes and all hoses and do a compression test on it aswell

 

Pm ed you mate Has the tps been changed?

Ade

 

was it running perfect and then all of a sudden this happed or was it always like this?
i would check your timing chain to see if the guide blade has shattered and the timing is gone slack as it sounds like a timing issue

 

As above regarding timing chain issues - but would expect you would hear the chain rattle.From memory the crank sensor feeds signal to the EDIS module, which then fires the coils.The ecu outputs a spark advance signal to the EDIS to provide spark advance as engine speed increases.If the EDIS is not getting this signal the engine will still run (EDIS will give default advance, 10deg I think) but will feel really flat and unwilling to rev.Check wiring from EDIS back to ecu - I did quite a bit with the BOA some years back and seem to remember the harness was sh$%*!

 

It's been running like this a couple of years he said. The blade would have deffo shat it's load by now.

 

Bob cams with the wrong washers ?

 

could be!!!

seen it done before

 

Were abouts in nireland you from. I have converted several sierras to 24v. i am located in northern ireland to so maybe i cud help if ya want.

 

as said have you looked @ the timing/cams/washers.ps the 24v needs 3 box's so the box you have took out not a good job (but that's not what it would be

 

fuel pump??you say its just a twincam one?are you getting good fuel pressure @ the back off fuel rail

 

how does it run?

just fine but with not as much power or just like a bag of shite?

wiring would be my first port of call

 

Is it EDIS6? If the saw wire is broken it will run at 10 degrees btdc timing all day long, and would feel very flat at that.

 

been told its possibly a wiring problem so going to look into that when we get a chance. Was running fine but just got bad recently. Cheers for all the replies!!

 

Maybe a bit late for this post now but im in ireland as well and have converted my sierra to 24v. Its def not the exhaust boxes thats the problem cos mine only has one and was running with the twincam pump for a good while without any problems. The only problem i had with mine was i put the plug leads on the coil the wrong way as some of the nos wore off the coil. The car didnt miss or run rough or anything just down on power. Sounds silly but worth a check anyway.

 

fault was found. Turned out that the fuel pump was shot so replaced it. Problem solved!