Hayk

iTrader: (1)

Ever since I bought the car, it always took a while to fire up on cold starts. I put in a new battery(Lexus), since the previous one was dead, and it seemed like it helped, but the problem is in something else. It cranks hard and turns over, but it takes a few seconds to fire up. And it seems like it got worse ever since the weather got colder.

I also had a few rough idles in the first few weeks of driving, I haven't experienced one in over a week (possibly two). The car starts up fine if it's still hot and it hasn't sat for too long. I believe it gets bad after about an hour.

I've had a couple of CEL's. One was for an O2 sensor(P1153) - it popped up when I was already on my way with the engine warmed up, but it hasn't reappeared since I cleared it. Another one was for a misfire at idle with cylinders 2, 4, and 6 (P0300, P0302, P0304, P0306). I got another one today while on the highway and with the engine warmed up, but I'll only be able to scan it tomorrow morning.

Here are some things that I knew prior to the purchase

-I am the fourth owner
-The car had about 175,400 miles and is 13 years old
-Previous owner just recently put in a new alternator (possibly aftermarket)
-Had some minor engine work to pass inspection (replaced a valve of some sort)
-Both valve covers were leaking and had quite a bit of dirty oil built up around the seams
-Camshafts seals were leaking
-The front brakes were shot (seized calipers)
-The owner said that he used to get a CEL when the gas needle was below the half way point
-The car threw out some blue smoke on my first start up (it sat at the PO's house for a while), but I haven't noticed it ever since I started driving it.
-The previous owner doesn't know when and if the timing belt has been changed


Here are some things I found and/or fixed after the purchase

-Replaced the valve cover and spark plug gaskets
-Replaced spark plugs
-Replaced spark plug wires
-Replaced Intake Manifold Gaskets (manifold to head)
-Replaced Intake Plenum Gasket (manifold to plenum)
-Replaced all 3 coolant hoses
-Completely drained and filled the cooling system
-Replaced Engine Oil and Filter
-Overhauled the front brakes (calipers, hoses, pads, and rotors)
-Replaced the Brake Fluid
-Noticed a lot of gunk in the throttle body and the intake plenum
-Cleaned up the butterfly valve with some Brake Cleaner but the IAC might still be gunked up
-Replaced the PCV valve, grommet, and hose
-Replaced the Battery
-The three front ignition coil connectors have been replaced

-The rear sway bar links and bushings are shot and need to be replaced (the bar is loose and the rear end clunks over bumps)
-Noticed some old gas stains around the tank, especially around the rear sway bar
-The rear sway bar was corroded right under the gas tank stains
-Front sway bar links are on the way out, but are not as bad as the rear.
-The heat shield for the catalytic converter was hanging loose due to rust - removed.
-The car remote is still weak after replacing its battery and the car battery


Here are my guesses:

Idle Air Control Valve
Crankshaft and/or Camshaft Position Sensor
Low Fuel Pressure/Fuel Pressure Regulator

What do you guys think? I understand that I need some professional diagnosis, so I'll try to get somebody to look at it this week. I don't want to get stranded...

mdbrown

Based on what you posted I would say IACV. A failing/failed cam or crank sensor would not cause a cold soak extended crank issue, it would cause a no start issue. Fuel pressure might be an issue but it wouldn't be the fuel pressure regulator in this case, it would be the fuel pump. There is a check valve in the fuel pump that closes when you shut the car off to keep fuel pressure in the line. When that goes bad the fuel will leak down back into the tank and it takes a few seconds for it to build back up again once that happens. Try this, next time it sits for awhile and is cold, turn the key on but don't start the car. Wait for 5 -7 seconds. Turn the key off and then start the car. If it starts right up then it's the fuel pump (when you turn the key to on without starting the car the pump runs for approx. 5 seconds to build pressure). If it doesn't change anything then the pump isn't the issue and it's likely the IACV.

Hayk

iTrader: (1)

I cycled the fuel pump about 3 times this morning before starting and it helped a bit. The car started up faster, but it still wasn't perfect. Oh and it was a bit warmer this morning, so that could have something to do with it too.

The CEL turned out to be P1153 with almost the same conditions as the first time I got it. (engine warm with the car travelling at about 60mph and accelerating)

mdbrown

Well, it sounds like you might have a failing O2 sensor but that has nothing to do with the extended crank time as you are in open loop at startup. Has the extended crank time ever not been an issue (like right after plug replacement) or has it been consistent since you bought the car. If you really want to verify the fuel issue you'll have to hook up a fuel pressure gauge and let the car sit and see if it bleeds down. If it does, that's your issue and you need to find out why. If it doesn't bleed down (after maybe 4-6 hours) then it may very well be the IACV. How does the car idle? Have you checked for leaks? If you have an injector seal leaking you could be sucking a little air... not a problem for a warm engine but a real issue for a cold one.

Hayk

iTrader: (1)

The car was always sort of weak on cold startups. After I replaced the battery, the first few weeks it used to crank really fast - to a point where I had to readjust how long I was holding the key for. This was probably a result of too much "juice". It has since gotten back to normal, but the start up still takes a while.

It runs very smooth once it fires up. No issues there, aside from the three times when I had a rough idle (vibration and possible misfire).

I bought two cans of Carb Cleaner, I just didn't have the motivation to take apart the throttle body again. So I'll try it out now.

My guess is that the problem is in the fuel pressure - it would definitely explain a lot of things. I just need to figure out how I'm going to get to school and my part time job without a car, once I drop it off for my mechanic to take a look. So that might take a week or two of planning.

Btw, I recorded about 24.5 mpg on Premium (93) with me flooring it twice, but mostly driving on the highway at 60-70mph.

pauloil

use the carb cleaner on the IACV!

Hayk

iTrader: (1)

I unbolted the throttle body and cleaned the IAC port with the carb cleaner - it was already pretty clean. I couldn't remove the actual valve, because I was afraid of stripping the Phillips screws, so I left that alone.

I think the issue is somewhere in the fuel lines. I now cycle the pump before starting and it seems to help a bit. I did notice that there is some gas smell out of the tail pipe when the car first fires up - but that could be normal (not sure).

mdbrown

It's possible you might have a malfunctioning fuel injector. If it's carboned up it might not be atomizing the fuel properly or it might be dripping. That would account for the raw fuel smell...

MikeLex

Check carefully your fuel pressure regulator to see if its leaking.

Hayk

iTrader: (1)

Where exactly is the fuel pressure regulator? I'm not good with fuel systems...

MikeLex

It's located between the engine oil filler cap and the throttle body. It looks like this: http://www.google.com/imgres?q=fuel+...UofT3Dw&zoom=1

Hayk

iTrader: (1)

I don't think the fuel pressure regulator is leaking. If it is in fact the fuel injectors, would I have to replace all of them at once or can I replace only the bad ones? I heard somewhere that mixing old and new injectors will cause the engine to run rough.

mdbrown

The injectors on this engine have plenty of room to spare so you shouldn't run into an issue mixing them. OTOH, check your fuel pressure first to see if you have a problem with the check valve in the fuel pump, that is far more likely than an injector issue.

tomjensen

Cold Start Valve?

mdbrown

Cold start valve is old school. On modern engines they increase injector pulse width to richen the fuel mixture. Verify proper operation of the coolant temp sensor as well, if it's getting a false warm signal then the ECM will not enrich the fuel mixture to compenstate for a cold start.