SR20DET harder and harder to start....smokes on accel - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

tire_machine · 08-05-2010, 09:24 AM

I am trying to figure out what cause(s) could be the root of my troubles.

It is just easier if I list this:

-Cold start / Fuel pump fuse : The car has always had a cold-start issue, and I haven't been able to fix it. (ECU is microtech). If it doesn't crank over the first time I try, it will blow my fuel pump fuse if I try again without turning the car completely off. Just recently the car has begun to do this even during the summer months (morning only). The fuse for my fuel pump is 10A

-Oil in the spark plugs / intake pipe : The car's compression is fine, but I found oil in spark plug 1 & 3. Also, the car has always shown blowby from having oil in the intake pipe

-Smoke after hard accel : After a hard pull (usually in 2nd), the exhause starts to smoke white (coolant). Car has test pipe.

I don't know if this is an issue, but after installing an AEM wideband, my AFR jumps all over the place when cruising with 10-20% throttle, going from rich to lean. This is most likely a tuning issue that needs to be looked at.

Sank you!

didderson · 08-05-2010, 11:40 AM

As far as the fuel pump goes, you might have a dying ground or connectors that are going bad and oxidizing somewhere along the line.
I'd suggest adding another ground to the fuel pump wiring directly from the source where it comes out of the gas tank. Might just be the fix.

Smoke after hard accel, seeing that oil pressure drops wrt rpms, could be turbo or valve seals for oil, but if it's coolant that's a head gasket leaking issue. If your coolant an oil stay separated and they aren't mixing, this is how you rule out if it's coolant or not. It's probably just oil from old seals creating smoke as pressure drops.

Clean your pcv valve might help blowby, get a catch can. for cylinders 1&3 being oily it's simple, either rings or valve seals letting oil in. I would assume it's not turbo related because it doesn't effect all cylinders equally. Some blowby is normal for journal bearing turbos.

nismoracingsx · 08-06-2010, 04:54 AM

Gonna put my money on valve seals since the car is getting harder to start and the plugs are getting oiled...guessing 2/4 of your plugs are getting fouled from oil and that's why your car is getting harder to start, and having fuel pump circuit issues isn't helping..

KiLLeR2001 · 08-06-2010, 06:37 PM

The fuse for the fuel pump should most definitely be 10A, not 5A.

tire_machine · 08-07-2010, 02:43 PM

Quote:

Originally Posted by KiLLeR2001

The fuse for the fuel pump should most definitely be 10A, not 5A.

my fault, 10A. Corrected

From this thread and others searched, valve seals seem like a probable cause. I don't have the tools to do this type of job at home, any idea on how much a shop would charge to do this? Would I have to get my head remachined as well??

I am going to change my spark plugs for the time being, and see if this changes anything

tire_machine · 08-09-2010, 12:46 PM

Something I forgot to mention is that my car only smokes at IDLE
does not smoke under load or decel.

Also, when I first start the car in the morning and drive, the rpms will initally drop when I give it gas, then rise. This problem only happens for the first 10 min of driving. When coming to a complete stop (during the initial 10 minutes), the rpms may drop all the way to 100 then slowly rise back up, almost killing the engine.

Is this still a cold start issue?>?

j87w · 08-09-2010, 09:31 PM

Why dont you just do a leakdown test and pinpoint the issue (if there is one) with the long block? If nothing comes up there then keep troubleshooting.

Hashiriya415 · 08-10-2010, 04:33 AM

i would not go anywhere unless fuel pump is working the way it should, get fuel pressure gauge, and check fuel pump flow 1quart in 30seconds minimum. Check voltage at pump, do a continuity test from the positive cable for pump to ground. I'm so sleepy its the best I could do for now.

08-05-2010, 09:24 AM	#1
tire_machine Leaky Injector Join Date: Dec 2008 Location: canada Posts: 104 Trader Rating: (0) Feedback Score: 0 reviews	SR20DET harder and harder to start....smokes on accel I am trying to figure out what cause(s) could be the root of my troubles. It is just easier if I list this: -Cold start / Fuel pump fuse : The car has always had a cold-start issue, and I haven't been able to fix it. (ECU is microtech). If it doesn't crank over the first time I try, it will blow my fuel pump fuse if I try again without turning the car completely off. Just recently the car has begun to do this even during the summer months (morning only). The fuse for my fuel pump is 10A -Oil in the spark plugs / intake pipe : The car's compression is fine, but I found oil in spark plug 1 & 3. Also, the car has always shown blowby from having oil in the intake pipe -Smoke after hard accel : After a hard pull (usually in 2nd), the exhause starts to smoke white (coolant). Car has test pipe. I don't know if this is an issue, but after installing an AEM wideband, my AFR jumps all over the place when cruising with 10-20% throttle, going from rich to lean. This is most likely a tuning issue that needs to be looked at. Sank you! Last edited by tire_machine; 08-07-2010 at 02:41 PM..

08-05-2010, 11:40 AM	#2
didderson Zilvia Member Join Date: Apr 2006 Location: Phila/Lancaster, PA Age: 39 Posts: 291 Trader Rating: (6) Feedback Score: 6 reviews	As far as the fuel pump goes, you might have a dying ground or connectors that are going bad and oxidizing somewhere along the line. I'd suggest adding another ground to the fuel pump wiring directly from the source where it comes out of the gas tank. Might just be the fix. Smoke after hard accel, seeing that oil pressure drops wrt rpms, could be turbo or valve seals for oil, but if it's coolant that's a head gasket leaking issue. If your coolant an oil stay separated and they aren't mixing, this is how you rule out if it's coolant or not. It's probably just oil from old seals creating smoke as pressure drops. Clean your pcv valve might help blowby, get a catch can. for cylinders 1&3 being oily it's simple, either rings or valve seals letting oil in. I would assume it's not turbo related because it doesn't effect all cylinders equally. Some blowby is normal for journal bearing turbos. __________________ Last edited by didderson; 08-05-2010 at 11:41 AM.. Reason: clarity

08-06-2010, 06:37 PM	#4
KiLLeR2001 Post Whore! Join Date: Jun 2007 Location: オーランドフロリダ Posts: 7,955 Trader Rating: (46) Feedback Score: 46 reviews	The fuse for the fuel pump should most definitely be 10A, not 5A. __________________

08-06-2010, 04:54 AM	#3
nismoracingsx Zilvia Addict Join Date: Sep 2007 Location: Alachua, FL Age: 37 Posts: 969 Trader Rating: (32) Feedback Score: 32 reviews	Gonna put my money on valve seals since the car is getting harder to start and the plugs are getting oiled...guessing 2/4 of your plugs are getting fouled from oil and that's why your car is getting harder to start, and having fuel pump circuit issues isn't helping..

08-09-2010, 12:46 PM	#6
tire_machine Leaky Injector Join Date: Dec 2008 Location: canada Posts: 104 Trader Rating: (0) Feedback Score: 0 reviews	Something I forgot to mention is that my car only smokes at IDLE does not smoke under load or decel. Also, when I first start the car in the morning and drive, the rpms will initally drop when I give it gas, then rise. This problem only happens for the first 10 min of driving. When coming to a complete stop (during the initial 10 minutes), the rpms may drop all the way to 100 then slowly rise back up, almost killing the engine. Is this still a cold start issue?>?

08-09-2010, 09:31 PM	#7
j87w Leaky Injector Join Date: Feb 2006 Location: nm Posts: 122 Trader Rating: (2) Feedback Score: 2 reviews	Why dont you just do a leakdown test and pinpoint the issue (if there is one) with the long block? If nothing comes up there then keep troubleshooting.

08-10-2010, 04:33 AM	#8
Hashiriya415 Zilvia FREAK! Join Date: Jun 2007 Location: San Francisco Age: 36 Posts: 1,007 Trader Rating: (22) Feedback Score: 22 reviews	i would not go anywhere unless fuel pump is working the way it should, get fuel pressure gauge, and check fuel pump flow 1quart in 30seconds minimum. Check voltage at pump, do a continuity test from the positive cable for pump to ground. I'm so sleepy its the best I could do for now.