Race Engine Forum UK

Hello everybody, I am new to the forum.
I am experiencing some problems with my 8v Delta under full load acceleraion (fourth and fifth gear). the car pulls nice upp to about 4000 rpm and then it feel like I would lift the accelerator for a millisecond and after that it keeps pulling. If I accelerate harder it appears more often throu the rpms, but it´s only in high gears.
I have an idea that the problem is in the head. I am running on stock headcams but the head is match ported to the inlet and exhaustmanifold, it has 16v injectors and throttlebody, tubular exhaust manifold. It´s currently running at 1,5 bar overboost, and it is proffesionally maped a little rich on fuel for everyday use.

From Sweden
Hector

Hi Hector,

Can i ask which ECU/Management you have on the car? if you are using the original ECU it maybe down to the crank sensor position, if the crank sensor is not positioned or spaced right you may experience a large jolt or big missfire, you must gap the sensor away from the crank pulley teeth betwwen 0.4mm and 1.00mm, it will be very time consuming as it will be trial and error until you find the correct gap.

I hope this helps.

Nino

check the fuel pump condition

Thanks for the tips!
The engine management is original so I will go and meassure the distance between the crank-sensor and triggerdisc. The fuelpump is a new walbro 255 lph. Testing will be in the spring because the engine is out for gearbox reinforcement and a new clutch. Unfortunately it´s below zero outside and soon they will put salt on the streets. Wich I do not want the car to experience.

//Hector

Walbro pumps are not "bad" as such, but they are not suited to very high pressures like the old bosch roller cell design is. At higher pressures the walbro pumps flowrate drops off dramatically. If you are running 1.5 bar boost and a rising rate regulator you could be running out of fuel flow. It may not be the source of your problem but just something to be aware of with those pumps to use them close to the rated pressure.