Single Point Injection Advice

[MC]

Have any of you guys heavily modified an SPi engine whilst maintaining the SPi, i.e head, cam, exhaust? If so how did you alter the mapping or fueling to cope?

ANyone got any ideas?

Does the SPi just use throttle position to determine airflow?

[Dicko]

thought they had a MAP sensor. i could be wrong though ill get the manual out in a bit

[MC]

Cheers Dicko, you're a star. Thought that might be the case.

[Dicko]

yup same as the later MPi's it has a MAP sensor according to my haynes

[Aragorn]

so what does the MAP sensor do then?

allows the ECU to compensate for mega engine mods :D????

u'll have noticed my post over at MiG MC but il;l say it again here

i wanna know yer findings with this as do a few other folks around here

[Dicko]

no a map sensor is what they used insted of a 'hot wire' system where a wire is used to calculate the air density going into the engine, or the 'gate' method which opended a gate and also had a seperate sensor to measure the temp.

A MAP sensor monitors the 'maximum absolute pressure' to calculate how much fuel to put into the engine and by how much to advance timing and other bits!
they are ok but i know of many problems that occur when you mod parts of the engine sometimes to the extent the map sensor cannot produce readings to compensate.
a problem some people have when putting on filters or a decat and the car cutting out on tickover it down to the map sensor not likeing it basically so beware!!

[locky]

Dicko, u no u say you have probs when modding the engine with the MAP, is it resettable like an ecu?
coz wen u fit an air filter/cam/wotever, arnt u sposed to disconnect the ecu for at least an hr so that it will reset itself!
so, does this map work the same way?

[Dicko]

all the MAP is, is a sensor. yes resetting the ECU helps but im saying certain mos cuase problems that cannot be fixed. sometimes byt adding an uprated chip fixes the problems.
not actually got a MAP sensor on my 16v but had 1 on my sri engine and had 1 or 2 probs wit that

[Stuart]

i may be wrong but i thought MAP was manifold absolute pressure :)

[Aragorn]

it is :D

[Dicko]

lol thats the 1 i was thinking of something else at the time ;) theres 2 meanings for MAP sensor stuck in me head :lol: