240 starts but then wont turn on again ??? plz help

[CHRISTIANELIO]

ok here is the story.. i have a 1991 240sx 5 spd . i blew the rings in that motor so i just purchased a 96 240sx motor obd 2 . i put the 1996 ka in the car already . i swapped my old dist. and throttle body like i researched on nico . i also tried lining up the dist like the dist. post said at tdc on compression stroke . well my car does not wanna start with the dist. at that location . the way i have gotten it started was by just turning the dist and cranking like 20 times ... well once i get it started it will stay on with tps unplugged and maf unplugged . once i plug them in it dies . and i will unplug them and car wont start again . it seems like the ignition timing is changing or something ... i dunno thats why i am posting .. only differences from my old motor obd1 and new one are... dist. throttlebody/tps/coolant sensor which i have already swapped to the 96 engine..

any ideas guys i tried searching already and i donot know what to do ! any help will be appreciated /...thanks

[jdmxbB]

make sure that there are no spliced wires that

were damaged during the install.

that may also have caused it to malfunction.

are you sure you have the right ECU in? Check

all the connections.

could be a bad starter? battery?

[CHRISTIANELIO]

i am still running the 91 ecu and wiring ... it cranks over . so its not battery or starter .. it will start then when i turn it off and try to start it again it wont like the timing changes

[90 S13 VG30ETT]

dude you need the OBD 2 ECU, and harness. and use the OBD 2 TB and Dis

[CHRISTIANELIO]

i have researched everywhere . they say to just swap tb with tps and dist. buying a whole ecu and wiring would = alot more confusion with wiring in the dash and stuff from what other member have said . only diffrences in the 96 ka and the 91 are tps and dist and coolant sensor plug. if i swap all these things the ecu should should not read any differences in the 2 motors am i right ?

[mac_daddy]

do u still have the 91 engine harness in it? obd1 ecu needs obd1 harness

[90 S13 VG30ETT]

is it the dual cam? varible timing?

[CHRISTIANELIO]

yes it is a dual cam engine . and since it is a 96 i guess it does have vtc . i still have the 91 ecu and 91 wiring hooked up to the 96 motor . would the vtc have to be hooked up ? on a 91 ecu and wiring harness ? ok here are some things that are not connected . on the 96 motor there are 2 connector right above the tps location (not the actual tps) on the 91 motor there is only one connector . so right now i just have the one connector plugged in since i do not have any more connectors on the 91 harness to connect to . also in the back of the engine there is a brown square connector from the ecu that is just there since the 96 motor doesnt have that sensor /connector on it i just left it hanging . here is my aim if someone could really help me figure it out (christianelio). i am really confused since i can get it started then when it dies or i turn it off i cant get it started again ..

[90 S13 VG30ETT]

i really think you need all the sensors pluged in. to feed the correct info to the computer.

[CHRISTIANELIO]

well it makes sense but to get it started ? the old engine didnt have the extra plug ? and the new motor does .... so i dunno if i need it or not

[Snake820]

I would pull the distributor make sure your car is on TDC and stab it back in but make sure your also not off a tooth. Most of the sensors are easily tested with a DVOM so try to find the specs for the TPS sensor it should be over 5 volts i beleieve during wide open throttle and check for a short to ground using a resistance test.

[CHRISTIANELIO]

yeah well with the tps and maf plugged in it wont start . i have tried putting motor th tdc by the 2nd mark from the left on the crank and stabbing the dist. back in with the lil rotor pointing to the number one spot . it wont start ??? is it possiblethat the dist timing changes ? /????? the only way i have gotten it to start is stabbing the dist in random spots ...... and once it is started i give it a lil gas and it dies or it dies when i plug in the tps or maf .... can timing fluctuate ?

[s13mike91]

to use the obd2 motor you have to use the obd1 intake manifold and exhaust manifold.

[CHRISTIANELIO]

i thought you could just use the tb and tps from the obd 1 motor on the obd 2 intake mani ?? instead of having to swap the whole intake manifold ??

[mac_daddy]

yea all you need is the lower intake manifold not the upper. i have a 98 ka in my s13

[s13mike91]

it would be better to use both obd1 manifolds.

[CHRISTIANELIO]

why would you need to use the lower intake manifold???? the difference is only in the plenum isnt ? the tb and emissions crap ? i didnt even think you had to swap them at all as long as you put ur obd 1 tps and tb on and the obd 1 dist

[mac_daddy]

that could be true but every writeup i ever read said to use the whole lower manifold. you could always try it and see if that was the problem