QuestionQUESTION: Dear Von Sudderth
My car is Aro 4*4 modified ; the specs are as follows :
Weight : 1300 KG
Engine : reconditioned Nissan Datsun 1488 CC
A15 A (original was Renault 1397 CC) RWD
Gearbox : 3N 71B (I think it is JATCO 3 speed ) with Kickdown sensor under throttle pedal . Original was renault 4 speed manual .
Differential: Mazda Ratio is 4.44 (original was Aro 4.3)
Wheel : 195/70/R14
the problem is the performance and consumption (150KM/20L);acceleration is poor and top speed is 120 KM/H . Local mechanic told me that gearbox has no problem such as slipping and the problem is the Diff ratio and I need to know the gears ratio of gearbox . Any solutions or comments are welcome . Thanks in advance .
ANSWER: Nebras,
The differential ratio is not helping the mileage. But, I would look at the engine and see about the plugs and make sure the vehicle has a nice tune. Make sure the timing is correct and the plugs are gapped properly.
---------- FOLLOW-UP ----------
QUESTION: Hi pal .....
I am using NGK BP6ES plugs and the gap is 1 mm (I don't know the right gap settings). I tried to set timing (mechanical distributer) to every possible position but the difference is very slight ! Also I dont know how to set camshaft with right setting . You mentioned that diff ratio is not helping the milage ,How about performance (acceleration) ,It matters, Isn't ?? Is the gearbox suitable for my car ? Are there any substitutes for it ?
Thanks in advance
AnswerNebras,
A higher ratio differential would help but I would not bother with changing the gearbox unless you could find one with an overdrive unit. An automatic overdrive out of an old Maxima or 280 Z would probably fit. On your engine I would check the fuel pressure and if you have carburetor be sure that the float is set correctly.
