Hi guys,

since ive repaired my car after broken lash adjusters, i have some cold start issue (that happened once or twice per year before even getting tuned.., but never had any cel,

at first(after repair) it happened every 2-3 cold start but now its every cold start...
idle was fluctuating before i broke the lash adjusters though....

The car will run bad the first 2 second then the idle will be fluctuating, the vaccuum sound from the intake is also fluctuating, you can hear and then not, then yes etc... as the rpm bounce...

About 3 weeks ago i got a P0496 CEL, i thought the cold start issue was related, my car had less throttle response than normal, not bad, but not what i remembered it was, so i tried the purge valve disconnect.

With it disconnected the car has better throttle response, sound smoother as well, feel very quick and has better fuel economy, it sound like its going from normal-to-rich-to-normal all the time with it connected...

But the cold start are still bad after the purge valve disconnected...

I did a video for a friend so he asked to hear the difference with the catless downpipe, but you can also hear the bad cold start

YouTube - ‪stock downpipe vs catless downpipe sound‬‏

I got a retune about a month ago thinking it may been the intake as my fuel mileage was also worst than normal, it did help the fuel trims were slightly off, but its still not as nice as normal... Vince said the tune was really good i had zero knock at that time.

Im a bit lost now that the disconnected purge valve do nothing to my problem, any guess what it can be?

I have no other CEL or DTC from the last time i scanned it at a garage.

Im going to change the plugs soon to test, but im thinking its the O2 sensor or may be maf? but im not sure if the maf would do that...

Once car is warm idle is stable, and with the purge disconnected the car runs good.


Thx for any tips

 

mine does the same thing! I have a catless downpipe, and i had the same thing happening to me..
is this bad?

 

Im sure its not too bad unless you never get it fixed, im trying to see what it can be...


I remember some saying if the oil was old it could do something like that because of the crank postioning sensor... if i remember right...

Thing is i did not changed the oil since the repair and used some assembly grease to reassemble the lash adjusters and rocker.... may be that didnt help? im changing oil soon and will replace the plugs...
hope that solve the problem..

 

Hey Mike, I had something similar happen to me last spring. Very up and down cold idle.

I unhooked the battery, cleaned the maf sensor, reconnected the battery.

Haven't seen it since. Hopefully, that might help.

 

What can i use to clean the maf? last time i looked at it there was some kind of electronic on it didnt wanted to apply anything on it...
can i just unhook the maf and see if that solve the cols start issue?

 

Mine has that to once in a while. A lot of time when I start mine up first thing in the morning my car will idle up and down alot. I replaced my purge solenoid and it didn't help.

With the lash adjustors, what were the symptoms of them being broken? Sluggish, underpowered?

 

I accidentaly gone from 3rd to 2nd at 100mph... lol
I had 3 rockers laying in the head and 1 broken lash. The car sounded like a subaru and didnt had power.

But my idle problem begun before that, and i think the coldstart is just a progression of that problem...

A friend told me it cannot be the O2 on startup because it is not used until catwarmup is finished, or something like that... may be someone can confirm?

Once warm, especially with the purge disconnected, the car run awesome, once the purge valve will be replaced all ill need to fix is that cold start issue...

 

Yeah mine just does this on cold start. It idles fine once the cars warm. It'll even do this if my car sets for a few hours it'll be like baaaa bumpbumpbump baaaa bumpbumpbump baaaa

 

Yeah same for me, only on cold start, at least im not the only one...

 

Yeah but I'm having other issues with my car that I can't seem to figure out. It spark knocks like a bitch and pulls timing all Over the place. Gotta love those mystery issues that can't seem to be resolved.

 

Yeah i know what you mean, just that problem is frustrating, hope you get it all fixed!

 

Yeah, I wish I could get it fixed. I wish someone around here knew a thing about these cars. I would be willing to take it to a shop if there were some good reputable ones. I have the car for sale because I'm tired of dealing with it.

 

P0496 is Evap purge selenoid on the intake manifold.

It causes all kinds of weird fueling issues at startup.

Fuel trims get wacky sometimes?

Dealer fixed mine under warranty and haven't had a problem in a month.

 

Hey Mike,

I got the exact same problem at startup. It just started a few weeks/months ago at most. Maybe a few weeks after I got tuned.

You think the purge valve could solve this issue? I read about that too, but I didn't kake ay move towards this issue yet.

By the way, where are you form around Mtl? Maybe I'd like to discuss with ya stuff about our cars. You can hit me up on MSN I guess doomtor@hotmail.com.

Dominic

 

From what Vince said my fuel trim were slightly off because of the intake, and all was good...

I have no way to see live though what is happening... but i could feel with the purge valve still connected that it was acting weird, less throttle response, spool slightly longer and less fuel economy...

With the purge valve disconnected it spool quick as hell and with 95F temp outside normaly i slightly spin the tires in 2nd gear on good pavement but now i roast them, i can really feel the downpipe and intake response now...

I got my purge valve today from mongorat a member here(thx mongorat) and will install it before the end of the week and see what happen....

But the purge disconnect did nothing to the cold start issue, today its very hot and after the job today, the car sitting all day, it started fine but idle was still going up and down...
i primed the car twice though... but i seen difference when its hotter the car start better...

I hope to get that fix and still keep the kind of power i get right now from the disconnected purge valve... lol

 

Im from south shore, just PM me when you want to meet, we can discuss about the cars no problem.


For the purge i dont know, i dont know if stamina had that problem too when he did all those test with the purge disconnected...
I need to change oil and plugs first and start from there.

If i can get some free time from the job ill order a set of NGK 5476's


If anyone find a cure to this issue please post!

 

Ok, just an update for anyone that had this problem after the install of an intake, at least the K&N...


Today i changed the purge valve and reconnect the line. I also changed all 4 plugs, gapped them 0.032, surprisingly the original were also at 0.032... i thought it was 0.035, one was 0.033 thought...


anyway... then i looked everything in the engine bay that ive messed with when i did the repair.
I found the 2 lines that go from the turbo to the front of engine bay were squeezed between the intake tube and the head...

The bigger line that go to the radiator have a dent, but theres no leak, and the smaller one that go from turbo to a sensor in front engine bay was really squeezed... but no damage really...

i re-route the smaller line over the bigger one, to make it free, then replugged the battery, started the car and the idle was really stable, and the vaccuum sound was steady as well. car was still a bit warm, cold enought to be in cat warmup mode, but tomorow morning will be the real test....

so far seem like the lines were the problem, so those that had this problem after the intake install may want to give it a look.

And the ne purge vavle made a difference over the old one, car run much smoother sound less 'loaded up'' or rich... but the throttle response is not as crisp as the disconnected purge valve trick...


The plugs on piston 2 and 3 were brighter than they were before i did the purge disconnect, almost like light tan color... does it mean lean? not too familiar reading plugs color...

instant fuel economy is better than it was on the old purge valve, but again the purge disconnect had even better instant fuel economy....


Will let you know if it is still going well tomorow..

 

Same issue here, but kinda intermittant, checked my hoses and look O.K.

 

Well this morning same thing happened... boooooo lol

But it was not as bad as in the video, but still does the same...
Once warmed the car run very nice tho with the new purge valve..

I think ill try some seafoam.

 

Hey Tony, I sprayed some brake cleaner on the maf wire then used compressed air to dry it. Technically, you aren't supposed to use brake cleaner for that but if you don't allow it to dry on the maf, it's fine.

I had already tried the purge valve disconnect before doing the maf. It didn't help at all.