Hard cold starts and pretty low vacuum???????

[rps13drift]

So i finaly got my sr20 runnig after like a year and a half rebuild. It took a few weeks to figure all the little bugs out to get it to idle and everything but it seems to start and run pretty good now every time.
There is 2 problems that i am having and I would appreciate some advice from my fellow 240 owners.

1- The car is pretty hard to get started when the motor is cold. it takes quite some cranking to get it to fire then i have to rev it some to keep it alive or else it will die.

2 low funky vacuum? I have been having a hard time with my low vacuum readings. I recently did the boost leak test thing and realized that all my swivel fittings that came with my topspeed manifold were pouring air through them. I couldnt find any BSPT replacement fittings so i brazed them at work to seal them and they dont leak at all any more. When the car is idleing my vacuum gauge literally is going bizerk from 4inhg to 8inhg? It never stays still at a reading! The needle is constantly moving. Im starting to think that i might need a new boost gauge for this one has been dropped a few times from trying to diagnose the motor.

So if any one has any helpful info please feeel free to share!
thanks
-mike-

[SoSideways]

There's a section in the FSM that deals specifically with mechanical issues.

You should look into that section, IIRC there's a specific procedure to go through for checking why your car is hard to start cold, and your vacuum readings are off.

My guess is, your cam timings are off.

[rps13drift]

There's a section in the FSM that deals specifically with mechanical issues.

You should look into that section, IIRC there's a specific procedure to go through for checking why your car is hard to start cold, and your vacuum readings are off.

My guess is, your cam timings are off.

Wouldnt the car not even start if my cam timing was off? I just recently timed my car about a week ago mechanicly and with a timing light and its perfect.

[SoSideways]

Wouldnt the car not even start if my cam timing was off? I just recently timed my car about a week ago mechanicly and with a timing light and its perfect.

Your cam timing can still be off from the crankshaft.

If it's off by a little, your car will still start, but it would be really hard to start (which is 1 of your symptoms), and it will also run very rough, with whacked out vacuum readings (your 2nd symptom).

If you were to rev the car, it will rev very slow and your car will drive very sluggish.

Provided I'm correct in that your cam timing is off.

[rps13drift]

Your cam timing can still be off from the crankshaft.

If it's off by a little, your car will still start, but it would be really hard to start (which is 1 of your symptoms), and it will also run very rough, with whacked out vacuum readings (your 2nd symptom).

If you were to rev the car, it will rev very slow and your car will drive very sluggish.

Provided I'm correct in that your cam timing is off.

Interesting! My car runs and idles spot on and it revs easily! Nothing that would concern me. The car isnt super hard to get started but i have to prime the fuel pump atleast 4 times for her to want to even start! I ran all new -6an lines and i have a pretty big fuel rail. My DSM buddy said that these fuel system upgrades would do that but i wasnt sure and thats why im asking here. Once the car has been started and its warm it will sart instantly. It just seems like if i let the car sit for a few hours the pressure will completely drain itself to 0 while when i was running stock lines it would always have some pressure in the lines.

[SoSideways]

Well, I have no clue what your mods are, and judging from your first post, I was diagnosing it per a stock SR.

You need to list your mods man.

[rps13drift]

Well, I have no clue what your mods are, and judging from your first post, I was diagnosing it per a stock SR.

You need to list your mods man.

Sorry
sr20det
apexi 1.1 head gasket
hks 264 in/ex step 2 cams /peakperformance valve springs
topspeed intake manifold
jim wolf ecu/740cc injectors/z32 maf
gt3076r
turbo 240 fuel rail/-6an feed-return fuel lines/aeroquip regulator/255lph pump

http://i220.photobucket.com/albums/dd107/rps13drift/Picture223.jpg

[Sileighty_85]

1) Sounds like its your Coolant Temp sensor - Hard starts when cold

2) are your RPM's fluctuating with the vacuum readings?
Where does the needle sit when the engine is off?
it should sit at "0" if not then you need a new gauge

[blueshark123]

o2 sensormay cause hard starts if u dont have all the wires connected or if its bad

[rps13drift]

1) Sounds like its your Coolant Temp sensor - Hard starts when cold

2) are your RPM's fluctuating with the vacuum readings?
Where does the needle sit when the engine is off?
it should sit at "0" if not then you need a new gauge

My coolant temp is 1 week old! lol! I changed that last week hoping for the best. I think my gauge could be fucked up though. It sits at alittle above 0 like positive boost when the motor is off

[Sileighty_85]

My coolant temp is 1 week old! lol! I changed that last week hoping for the best. I think my gauge could be fucked up though. It sits at alittle above 0 like positive boost when the motor is off

The dual CTS plug or single plug?
Did you check the ECU for Codes?

I see you are running some Cam's, because of the lift if will cause a "lope" which will cause your Idle to fluctuate
Is the ECU tuned for the Cams?

[djcobra]

I'm also thinking 'Coolant Temp Sensor' I have a similar problem, whenever I start the car it hunts for idle (which is set at ~1100rpm due to the cams i've installed). After 10-15 seconds of the car hunting for idle it runs great. I'll be changing my Sensor this week and i'll let you know if it made any diff..

Mods:

S14 SR20DET (kouki)
GT28RS (disco)
Apex'i 1.1mm HG
HKS Step 2 Cams, 256in/264ex
HKS Springs
Peak Performance Retainers
HKS 555cc Injectors
PowerFC

bleh bleh bleh bleh...

[rps13drift]

The dual CTS plug or single plug?
Did you check the ECU for Codes?

I see you are running some Cam's, because of the lift if will cause a "lope" which will cause your Idle to fluctuate
Is the ECU tuned for the Cams?


i changed the dual plug cts for the ecu. Not the gauge. My idle from the cams does indeed flctuate but not like crazy! Your can realy hear them in the exhaust note at idle though. And for the record No ecu tuner tunes for cams! i spoke with ben from jim wolfe a few weeks ago about that topic and he said you cant rom tune for cams.

[Sileighty_85]

The Idle fluctuation is normal when running cams, if you had a PFC the Idle would level out.

Do you have Adj. Cam Gears?

[rps13drift]

The Idle fluctuation is normal when running cams, if you had a PFC the Idle would level out.

Do you have Adj. Cam Gears?

No im running factory cam gears. Should i have got those? I heard that they barely do anything

[Sileighty_85]

Some One made a thread about it here it is

http://zilvia.net/f/tech-talk/202945-aftermarket-cam-gears-how-much-power-expect-them.html

Its not really for gaining power more like recovering and for tuning the Cams

[rps13drift]

Interesting! Maybe ill look into them. I just talked to a friend and im going to hook up his boost gauge tonite. Hopefully all is well and its indeed my gauge that is fucked up.

[xsparc]

not sure if this has been said... but for having to prime the fuel system before starting sounds like a FPR problem. same thing happend on my gfs sentra.