20V MK1 Engine Swap st 20v not quite perfect!

honeyborne · 06-07-2007, 04:06 PM

ok the car starts runs and drives. it seems to be over fueling a little and gives a few small pops etc from the exhaust. it has no power at all, its completely gutless... i have had suggestions from people that it could be the afm or the tps. i have replaced the afm and its the same. i have tried to test the tps and it is recieving a 5v constant positive and another pin decreases in voltage when the accelerater is applied, surely this means it works. the other thing the car idles perfectly at 750rpm. if you open the throttle and hold the revs at anything say 3000 revs it sits there perfectly and will sound fine. surely this means that the timing signal, rpm signal, air mass signal, fuel mix etc is all getting to the ecu.... the only problems are it will only rev upto 6000 revs max and sounds like its red lining.... also if you try and increase or decrease the revs quickly it sometimes pops or back fires etc.

i know a bit about the mechanical side of cars but i'm learning about the electrical side now.

help required please. i think its a electrical issue?

mopwer · 06-07-2007, 04:34 PM

Usually backfires are an idication that it is leaning out, or the timing is off. Also, a tune up never hurts (plugs, wires, cap rotor).

Greg

lsgheero · 06-11-2007, 10:17 AM

i agree sounds like a timing issue specially due to lack of power.

06-07-2007, 04:06 PM	#1 (permalink)
honeyborne No Skills Join Date: Apr 2007 Posts: 9 Thanks: 1 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	st 20v not quite perfect! ok the car starts runs and drives. it seems to be over fueling a little and gives a few small pops etc from the exhaust. it has no power at all, its completely gutless... i have had suggestions from people that it could be the afm or the tps. i have replaced the afm and its the same. i have tried to test the tps and it is recieving a 5v constant positive and another pin decreases in voltage when the accelerater is applied, surely this means it works. the other thing the car idles perfectly at 750rpm. if you open the throttle and hold the revs at anything say 3000 revs it sits there perfectly and will sound fine. surely this means that the timing signal, rpm signal, air mass signal, fuel mix etc is all getting to the ecu.... the only problems are it will only rev upto 6000 revs max and sounds like its red lining.... also if you try and increase or decrease the revs quickly it sometimes pops or back fires etc. i know a bit about the mechanical side of cars but i'm learning about the electrical side now. help required please. i think its a electrical issue?

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06-07-2007, 04:34 PM	#2 (permalink)
mopwer 933SGTE Join Date: Nov 2006 Location: Peoria, AZ Posts: 1,096 Thanks: 24 Thanked 14 Times in 14 Posts My Google Map iTrader Rating: (12/100% )	Usually backfires are an idication that it is leaning out, or the timing is off. Also, a tune up never hurts (plugs, wires, cap rotor). Greg

06-11-2007, 10:17 AM	#3 (permalink)
lsgheero RAR! Join Date: Feb 2007 Location: Arizona Posts: 747 Thanks: 9 Thanked 31 Times in 31 Posts My Google Map iTrader Rating: (1/100% )	i agree sounds like a timing issue specially due to lack of power.