Hi all got a mk4 xr3i efi , could anyone give me the best way to check if timings in line , as it seems to be a bit powerless even though camshaft looks ok . Any info appreciated

 

Have you measured the lobes, looking down the tappet port will only tell you so much. I have to be honest, I found my wife's XR2i to be slower and flatter than my K-Jet XR3i but the thing with CVHs is that they vary so much.

Best thing to do is get it on a rolling road, they can check the mixture all through the rev range and load and can then tell you what is going on with the engine. A lot more accurate than replacing bits in the hope that it sorts the problem.

One thing on those is the map sensor, they tend to go a bit wonky. Check that there are not any air leaks in any of the hoses as this could be upsetting things. What colour are the spark plugs and does the car drive well or does it hesitate a lot?

Breather pipe on the right side of the engine, remove from rocker cover and the block and check that it is clear

 

To check the timing, line the crank pulley notch up with the 0 on the cover and see if the triangle on the cam pulley points to the mark on the head

 

Hi plugs look ok , its got a new map sensor ,and a potentiometer , and runs ok but doesnt seem to get up to speed quickly though .

 

Yes this to check camshaft timing rather than spark timing:

Remove the top cambelt cover, then align the notch in crank pulley as mentioned above with 0 on the lower cover and make sure the triangle on the camshaft pulley (located on the inside of the pulley in one of the circles) aligns with a small hole on the head.

Seriously consider a rolling road though, it will save you money in the long run and it isn't as expensive as you think. In the SW it's usually Ł35 for a session, from here you can then replace or optimise as required, it could be something simple like the fueling needs to be adjusted. When you replaces the potentiometer was it brand new and was it setup on a gas analyser?

 

check the tcp is set right as this can cause some sluggishness just done my festa as it was gutless even for a 1.1 struggled to get 70, hit 98 last night!

 

whats tcp or am i being a bit thick

 

Throttle position sensor maybe although that is TPS

 

throttle control positioner should be 0volts with ignition on and when throttle is open fully should be 5volts if i remember right, there is a page tht tells you how to set them think this it it:
http://www.allfordmustangs.com/forum...r-voltage.html

copy and paste into search bar does make a difference!

 

yep tps me being thick lol worth a check with multimeter green wire i think?

 

Thankyou all for your feedback ,appreciated will do some checks and hopefully will get somewhere .