S5 na motor into S4 NA chassis woes
05-26-09, 05:24 PM
#1
S5 na motor into S4 NA chassis woes
Okay I recently have swapped in a motor from an 89 and I just can't keep it running, but I'll have updates on that later.
I am using the S4 electronics/injectors etc, s4 TB/tps, went premix to avoid front cover/omp problems, s4 water pump and wp housing.
*NOTE* when using the s4 WP housing you can remove the front pulley on the s5 motor without pulling the WP housing off, pretty neat.
What I am using from the S5 are the intake manifolds, alternator, primary and secondary fuel rails.
all of the emissions were removed, even the old S4 NA motor had no emissions on it so I'm familiar with the procedures
Issue #1 IDLE/BAC
there was a vacuum leak but that was fixed by not using the spacer for the primary fuel rail (go figure) and now without the BAC installed its having a hunting idle (which i normally wouldn't care about) but I cant time it with a 1300rpm idle.
BUT I would have kept the BAC except that the S4 BAC does not fit on the S5 intake manifold when using the S5 secondary fuel rail. I don't have an s4 fuel rail laying around to try and see either. The problem with it is that the electrical connector on the N326/7 BAC valve hits the fuel rail so you can't plug it into the harness.
so can I use the N350 BAC valve on the S4 electronics? since the electrical connector faces another way
right now I will live w/o the BAC if I can lower the idle by using the adjusting screw and see if I can bring it down to an timeable level.
issue #2 WONT STAY RUNNING
when ever I can get it started it will run great cold and then when it warms up it dies, the fuel pump just went out in it and with that replaced it actually wants to start this time which is nice. I've gone through 2 bottle of seafoam through the intake and got TONS of white smoke but that wasn't enough, I think it is still pretty carboned up apex seal spring on the rear rotor and I cant drive it around under load since I dont think its timed right. I tried going around the block and it began to miss and backfire a little bit before it just quit on me.
it ran awesome on seafoam you could tell the engine liked it and not to mention I got it to puff out white smoke rings lol
I am using the S4 electronics/injectors etc, s4 TB/tps, went premix to avoid front cover/omp problems, s4 water pump and wp housing.
*NOTE* when using the s4 WP housing you can remove the front pulley on the s5 motor without pulling the WP housing off, pretty neat.
What I am using from the S5 are the intake manifolds, alternator, primary and secondary fuel rails.
all of the emissions were removed, even the old S4 NA motor had no emissions on it so I'm familiar with the procedures
Issue #1 IDLE/BAC
there was a vacuum leak but that was fixed by not using the spacer for the primary fuel rail (go figure) and now without the BAC installed its having a hunting idle (which i normally wouldn't care about) but I cant time it with a 1300rpm idle.
BUT I would have kept the BAC except that the S4 BAC does not fit on the S5 intake manifold when using the S5 secondary fuel rail. I don't have an s4 fuel rail laying around to try and see either. The problem with it is that the electrical connector on the N326/7 BAC valve hits the fuel rail so you can't plug it into the harness.
so can I use the N350 BAC valve on the S4 electronics? since the electrical connector faces another way
right now I will live w/o the BAC if I can lower the idle by using the adjusting screw and see if I can bring it down to an timeable level.
issue #2 WONT STAY RUNNING
when ever I can get it started it will run great cold and then when it warms up it dies, the fuel pump just went out in it and with that replaced it actually wants to start this time which is nice. I've gone through 2 bottle of seafoam through the intake and got TONS of white smoke but that wasn't enough, I think it is still pretty carboned up apex seal spring on the rear rotor and I cant drive it around under load since I dont think its timed right. I tried going around the block and it began to miss and backfire a little bit before it just quit on me.
it ran awesome on seafoam you could tell the engine liked it and not to mention I got it to puff out white smoke rings lol
05-26-09, 06:01 PM
#3
nope all leaks are gone, its like its running out of fuel, when I can get it to idle I crack open the throttle and it quits. either that or a reallly bad sticking seal. which I'm not looking forward to fixing.
I haven't removed the CAS at all so its still in there right.
the injectors are fine, had them cleaned and balanced and they have the correct spray pattern.
this is really pissing me off since right now it should be running.
I haven't removed the CAS at all so its still in there right.
the injectors are fine, had them cleaned and balanced and they have the correct spray pattern.
this is really pissing me off since right now it should be running.
05-26-09, 07:56 PM
#6
The S4 BAC can be made to fit under the S5 secondary fuel rail if you trim a little plastic off of the harness-side plug. I used one on my S4 engine w/ S5 manifolds. But as 2slow4stock mentioned, an S5 BAC will work too if you adapt the plug to fit. They work exactly the same.
Have you tested the coolant temp sensor on the back of the water pump housing? Maybe there's something going on with it once the coolant temp rises, which could give the ECU bad info. Its resistance values are used in the fuel injection calculations.
Have you tested the coolant temp sensor on the back of the water pump housing? Maybe there's something going on with it once the coolant temp rises, which could give the ECU bad info. Its resistance values are used in the fuel injection calculations.
05-26-09, 08:24 PM
#7
the coolant temp sensor is fine and the car wont stay running when its cold even because right now it seems like its a fuel pressure problem.
I jumper the fuel pump connector by the AFM and I can hear the thing turn on but I squeeze the return and feed lines I dont feel any pressure. there is gas in the tank, its not a whole lot but its enough to register on the fuel level gauge around 1/8th tank.
normally when you jumper the connector you can hear the fuel lines build up pressure but this is not happening again.
I unhooked the fuel line to the pump and it like puffs out just a little bit of fuel from time to time not like a steady stream or anything.
this is a known good fuel pump that I just swapped out my old bad walbro 255 thats been in there for 5 years and it fired right up and idled.
its liked my car is eating fuel pumps. WTF?
and yes the fuel filter and lines are new.
I'd try swapping out for the S4 sec fuel rail but I'm missing the large end banjo bolt, opp side of FPR.
I jumper the fuel pump connector by the AFM and I can hear the thing turn on but I squeeze the return and feed lines I dont feel any pressure. there is gas in the tank, its not a whole lot but its enough to register on the fuel level gauge around 1/8th tank.
normally when you jumper the connector you can hear the fuel lines build up pressure but this is not happening again.
I unhooked the fuel line to the pump and it like puffs out just a little bit of fuel from time to time not like a steady stream or anything.
this is a known good fuel pump that I just swapped out my old bad walbro 255 thats been in there for 5 years and it fired right up and idled.
its liked my car is eating fuel pumps. WTF?
and yes the fuel filter and lines are new.
I'd try swapping out for the S4 sec fuel rail but I'm missing the large end banjo bolt, opp side of FPR.
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05-27-09, 05:31 PM
#10
Defintely get a gauge tee'd in to check fuel pressure. What kind of pump is in there now? A stock pump or another walbro? If it's a walbro did you get it off ebay or somewhere you can trust not to sell you a chinese knock-off? The FSM has fuel pressure specs for stock pumps. It should be around 40 psi, if the engine is off & a gauge is tee'd into the feed line, and I think 70 or 80 psi or so if you dead end the feed line with a gauge.
