Sentra hard start when cold

[omegaman316]

I have a 2005 Nissan Sentra S 1.8 with 150,000 miles. Which does a Very, Very, hard start when the engine is cold. (I am in GA in the summer here). And sometime does not want to start at all resulting in a flood. I have to pump the gas paddle and one by one the pistons catch and it starts. I get the p0300 (Random miss fire) and p0303 (Piston 3 missing). Once the engine is warm/hot or running, it does not miss. Here is what I have done so far troubleshooting:

All sparks are wet.
New Battery.
Shuffled Sparks, Coil packs, and injectors but I keep getting p0303 and p0300 code.
Compression when cold is 85 PSI+ cold crank on all 4 pistons. No mix of coolant/oil or loss of coolant.
I have replaced the fuel regulator, filter, and pump about 6 months ago and I wait unit the fuel pump turns off before cranking.
Cleaned MAF and it got worst. Replaced MAF and it still hates me.
Replaced the crank position sensor and swapped CAM position sensor with the crank position.
Cleaned the throttle body and now I get the code p0507 (Idle too high). Tried to get the ECM to relearn it by the ignition cycle and throttle pump method and still get the code.
Reset the ECM by the similar ignition cycle and throttle pump.
Replaced the spark plugs with NGK Platinum and it now starts better, but still have to pump the throttle.

Now I am getting the code p0507 (tank level sensor issue).

I am getting sick of working on this but really hate to take my car to someone and pay a ton of money.

Any ideas that I might have missed. I have googled the issue left and right and read up on the TSB about this car and similar models. The FSM does not help much on troubleshooting hard start or I must have got lost in it's 2,000 something pages.

I am going nuts on this problem! Any ideas?

[OMGFWDSRB13]

Ok,

The FSM spec for compression on your QG18 is 192psi, +/-14psi, at operating temperature, and (importantly) with the throttle on the floor. You'd be surprised how many people aren't aware of that last part; sometimes it can make a significant difference.

85psi seems awfully low. Did you have the throttle open when you compression tested it last time? Any mechanical issues with your car before? Had the engine replaced before?

Next time, if you can, grab a friend and test it after it's been running.
/h

[omegaman316]

Sounds like I have a project tomorrow! I found the instructions on page EM-55. I have no idea why I was thinking anything above 80 was good.

Never any mechanical problems. No loss of HP, loss of gas mileage, or rough running other than crappy starting when cold. I had it since 85,000 and I took good care of it.

Will report tomorrow!

[omegaman316]

I just did the compression check. I have 195 to 205 PSI per piston. I checked the gap on the plugs and all are good. 0.043 per the FSM.

Anything I might have missed?

[06_blkout]

Have you tried doing an idle air volume learn?

[omegaman316]

Figured it out! I noticed that the coolant was low. I topped it off and drove it for about a week and my heated stopped working. The coolant was very, very low. I remember looking at the spark plug for piston 3 in the past and it had rust on it. I popped plug 3 and found water in the piston.

After a hard start, it ran fine so I drop it to my parent's place and swapped the head gasket. Now it starts great!

Stupid thing is that I good good compression at 195 PSI+ on all cylinders.

Thanks guys for your input!

[Pulsar-nx-kid]

Ok so just so you know if your heater core is bad you can blow the head gasket! is you heat working proper? You don't want to replace the gasket again.

[06_blkout]

Glad you got your car fixed without bring it to a shop, always a good thing.

[omegaman316]

Pulsar-nx-kid,

I flushed the system about 4 or 5 months ago and I was getting good flow from the water hose through the heater core. I think the reason why the heater crapped out was because the air bubbles was getting trapped in the heater core causing it not to work. So far, no fluid loss and the heater is toasty!

06_blkout,

I was just about to break down and take it to a shop. The stupid thing was I get getting good compression. The head gasket must be working like a one way valve allowing water in but not pressure out. In the end it cost me 95 bucks for the head gasket kit (intake, exhaust, head, and such) from Advanced Auto (Yeah, I could have paid less online, but I needed it then and now) and my father and I 1.5 days working on it. We are very slow mechanics, but know how to work a ratchet and read the FSM. That does not include the 40 bucks for a MAF off eBay, Sparks, hours of frustration, and the possibility of a weaken starter.

Since age 10, I was working on cars and such. I have never taken any of my cars/trucks to the shop less tires and alinements. I have rebuilt engines and transmissions. Mainly out of nessassity because I was in college and broke. Now since I have some money, I still rather work with my hands. Pushing paperwork gets old fast.

Once again, thanks guys for the input!

[06_blkout]

Pulsar-nx-kid,

I flushed the system about 4 or 5 months ago and I was getting good flow from the water hose through the heater core. I think the reason why the heater crapped out was because the air bubbles was getting trapped in the heater core causing it not to work. So far, no fluid loss and the heater is toasty!

06_blkout,

I was just about to break down and take it to a shop. The stupid thing was I get getting good compression. The head gasket must be working like a one way valve allowing water in but not pressure out. In the end it cost me 95 bucks for the head gasket kit (intake, exhaust, head, and such) from Advanced Auto (Yeah, I could have paid less online, but I needed it then and now) and my father and I 1.5 days working on it. We are very slow mechanics, but know how to work a ratchet and read the FSM. That does not include the 40 bucks for a MAF off eBay, Sparks, hours of frustration, and the possibility of a weaken starter.

Since age 10, I was working on cars and such. I have never taken any of my cars/trucks to the shop less tires and alinements. I have rebuilt engines and transmissions. Mainly out of nessassity because I was in college and broke. Now since I have some money, I still rather work with my hands. Pushing paperwork gets old fast.

Once again, thanks guys for the input!

Not a problem man, we're always here to help. No worries about being a slow mechanic, I was in a shop for 8 years, and I'm still slow lol. All that matters is that it comes out right!