starting issues after car sits for a while

[CrisZenithBlue]

updating this thread.

I havent had a CEL for a couple of years now, granted i drove it a lot less. But i continued to have the "hot start" issues, where if the car would sit for a while after being hot it would have a bit of an issue to crank, like take 2-3 seconds and maybe a touch of throttle to get it going. Also had this issue when starting right after filling with gas on a hot day.

The other day i was driving and P0455 pops up. because i already checked fuel pressure, smoked for leaks and replaced the purge valve (next to the intake), i went ahead and bought the Fuel Tank Bleeder Valve and Purge Valve that's on the charcoal canister (figured, while in there). i'm going to replace these soon, reset the CEL and see if i still have the hot start issues. oh, i replaced the crankshaft position sensor a long time ago to eliminate it as a possible cause.

i'll report back after these fixes

[maxnine11]

Cris, did you ever get this issue resolved ??

[CrisZenithBlue]

Not yet. I drove the car less and kinda lived with it because it wasn't a big problem. Im driving the car more now so will need to get back on it, maybe replace that one valve that I haven't yet, the one behind the headlight. Ill probably do that soon, if that doesn't do it, its back to the drawing board..

[blue62]

Cris,
Your P1128 and P1130 codes are telling you that the fuel system on both banks has reached the rich limit trigger point. So your fuel trims should be showing negative trims or taking fuel away. Your P0455 is as you know a fuel tank ventilation major leak.
So what is happening is you have a situation where fuel fumes from the fuel tank are coming into the intake from the EVAP system.
Causing hard starting when hot and most likely the P1128 and P1130 codes

Because of the above condition when the car is hot or warm it has trouble starting because the fuel mixture is to rich.
When you step on the gas pedal the reason that it helps is because you are giving the engine more air not more gas. Thus leaning the fuel mixture in the cylinders out and allowing the engine to start.

On a car with electronic fuel injection the ECU controls the fuel.
All that happens when you step on the gas pedal is the throttle plate opens farther allowing more air in and also the throttle position sensor tell the ECU/DME the throttle plate position.

[deemce1]

"remember these issues started as soon as i refurbished injectors and the gas tank was opened as well by my mechanic who supposedly tightened down the fuel pump which was loose. car never had an issue starting up before. "

thanks,

Cristian[/QUOTE]

When this happens to me, I always go back to the old saying "If it was working and you did something and now it no longer works..... you broke it. Go back and retrace your steps"

Good luck. We can feel the frustration in your posts.

[CrisZenithBlue]

Wanted to update this post, because i did and learned some things in the meantime. The P1128 and P1130 codes were actually caused by having the wrong MAF version, i did sort that out quite a while ago and no more codes, definitely closed the book on those.

The P0455 code was indeed from a major evap leak, it was actually the fuel sender unit. Under the battery tray the plastic neck that the line connects to snapped of, it was old yellow brittle plastic. i replaced the fuel sender, made sure the fuel pump was sitting right and fixed that issue right away, no more fuel fumes coming into the cabin.

I still have the hot start issue, and i believe what is happening is what Blue62 and particlewave (in an older post here) mentioned, fumes ending up in the intake, when i press the gas a bit more air is mixed in and it starts right up, never takes more than 2-3 seconds. it's most likely something in the EVAP ecosystem that is not doing its job.

I was going to change that valve that sits behind the right headlight, i have the part just never got around to replacing it. I thought it was supposed to go on the charcoal canister according to DYI guides but i guess that was for a different version, mine goes behind the headlight along with another valve. If that doesnt do it i'm considering replacing the charcoal canister.

I'm gonna do that soon and report back. Thanks to all that shared really valuable info, very much appreciated!

[Stl-986]

Originally Posted by CrisZenithBlue

Wanted to update this post, because i did and learned some things in the meantime. The P1128 and P1130 codes were actually caused by having the wrong MAF version,

Not sure where you read that, but that isn't right at all. 1128 & 1130 make many people think it's the maf and it almost always isn't the maf.

[CrisZenithBlue]

Originally Posted by Stl-986

Not sure where you read that, but that isn't right at all. 1128 & 1130 make many people think it's the maf and it almost always isn't the maf.

I know what you're saying. Those codes were the first issue I ever had with the car and i did the whole shebang, smoke tested for vacuum leaks and all that good stuff. I later realized that I didn't buy the correct MAF for my car, I bought the updated one but it wasn't the right one for my ECU. When I replaced the MAF with the right one the codes went away. This was a few years ago.

[blue62]

Cris,
The EVAP system can cause all kinds of issues.
It is a simple system the issue is access to all the hoses and valves.
Stay with it and concentrate on that system. As you know your hard starting is from an over rich mixture when hot.
Not many things can cause that.
The EVAP system is the most likely at this point.
Let us know how you go. Always interested in outcomes.

[Rob175]

STILL wondering...........IF the car didn't have this problem BEFORE you had your mechanic work on the car AND NOW YOU DO.........why didn't you just take it back to the mechanic and tell his "it's not right, fix it!".........Just wondering?

[blue62]

Cris,
Have you tried reclibrating your E-gas (throttle)?????
To see if it helps your hard starting when hot issue???
It's a long shot but easy to do.

I do really think it is an EVAP issue.
Perhaps when the mechanic removed the intake he did something to the EVAP hoses valves or connections. Hoses and some valves for the EVAP are right there.

If you want to give recalibrating the E-gas a shot, this is what you do.
Disconnect the battery for a few minutes so the ECU drops the E-gas calibration settings.
Reconnect the battery.
Turn the ignition to the on position "do not start the car"
Do not touch the gas pedal.
Let it set that way for at least 1 minute.
Turn key off for at least 10 seconds.
Start car.
Thats all there is to it.

[CrisZenithBlue]

Originally Posted by Rob175

STILL wondering...........IF the car didn't have this problem BEFORE you had your mechanic work on the car AND NOW YOU DO.........why didn't you just take it back to the mechanic and tell his "it's not right, fix it!".........Just wondering?

Looking back, i think i might have had that issue before but i didnt realize it or pay attention to it. In that time i was only doing round trip drives with the car and would almost never shut the engine off and restart except once when first starting up so i didnt notice. I think i noticed the hot start issue when filling up with gas on a very hot day but chalked it up to "probably not a big deal" since it started right up.

the only work the mechanic recently did was taking the injectors out, i got them refurbished and then he put them in again. i think i did eliminate the possibility of the injectors not sitting correctly or having a pinched seal and losing fuel pressure because i did the fuel pressure test and it seemed fine (also documented on here). Also, the car starts right up even after sitting for days so that tells me the pressure doesnt bleed out.

[CrisZenithBlue]

Originally Posted by blue62

Cris,
Have you tried reclibrating your E-gas (throttle)?????
To see if it helps your hard starting when hot issue???
It's a long shot but easy to do.

I do really think it is an EVAP issue.
Perhaps when the mechanic removed the intake he did something to the EVAP hoses valves or connections. Hoses and some valves for the EVAP are right there.

If you want to give recalibrating the E-gas a shot, this is what you do.
Disconnect the battery for a few minutes so the ECU drops the E-gas calibration settings.
Reconnect the battery.
Turn the ignition to the on position "do not start the car"
Do not touch the gas pedal.
Let it set that way for at least 1 minute.
Turn key off for at least 10 seconds.
Start car.
Thats all there is to it.

I'll try that, nothing to lose
also, i'm doing the plenum and 74mm throttle body upgrade soon and will have a look around the intake. The only thing i tried there was replacing the purge valve that sits on the left side of the engine, what else is there from the EVAP system that i could look for?

[blue62]

Originally Posted by CrisZenithBlue

I'll try that, nothing to lose
also, i'm doing the plenum and 74mm throttle body upgrade soon and will have a look around the intake. The only thing i tried there was replacing the purge valve that sits on the left side of the engine, what else is there from the EVAP system that i could look for?

There is a diagram of the system in the Bentley service manual if you have one.
Or do a search here on the forum. I am sure there is a picture.

If that purge valve and the vacuum hose is easy to get to????
you could try pinching it off or disconnecting it from the intake.
Plug the intake where it disconnects.
Take the car for a drive to get it warmed up.
Then see how it restarts while hot.

If something is in the EVAP system that is causing the hot start issue.
disconnecting it for a short time may make a difference.

Keep us posted.

Just another thought: Have you looked at your fuel trims????
If your getting fuel vapors in the intake from the EVAP system, you should be showing Negative Short Term Fuel Trims.