purge valve testing

[SEA320]

In trying to figure out the various issues with my 95 E320, I was checking the purge valve. (my car, apparently, while a '95 technically, has '96 engine components) It's the special edition from '95, not sure what that means, if anyone can shed light on that, just out of curiosity.

anyway, the purge valve...if I take the vacuum line (from the engine) off, the engine runs poorly. If I take it off and plug it, the engine runs fine. What is this information telling me? I'm assuming it's saying that the valve is working. I don't hear or feel any clicking though (I guess this is the sound it's s'posed to make?

thanks

[Arthur Dalton]

Do you have a purge code??

[SEA320]

well, I've been dealing with this idle surging issue as of late, although I replaced the EGR valve, O2 sensor, fuel pressure reg, cleaned the MAF. Has been running good for 3 days so far.

no specific code, the little black box indicates a 4 and 5 code, CEL is on. I'm rebuilding the code reader tonite to see if I can get anything more specific.

Really, I was just curious what that particular scenario meant, the one I stated in the original post.

[Arthur Dalton]

You mean this one ??

>anyway, the purge valve...if I take the vacuum line (from the engine) off, the engine runs poorly. If I take it off and plug it, the engine runs fine. What is this information telling me? >

That only means you have taken a vac hose off and created a vac leak that has resullted in a lean mixture , resulting in a poorly running engine...and then you fixed the vac leak you created by plugging it and now the car no longer has that vac leak and that has corrected the fuel mixture and is running Ok again..that's all it means,,it has nothing to do with checking the Purge system , as that would be upstream for what you did.
You simply made a vac leak.
If the purge was not working, you would most likely see a purge code.
Check if you do. You would be looking for a 21 on DM or a 36 on HFM [pin#8]

[SEA320]

Ok,
Pin 8- code 36 (purge valve) could this have been caused from me pulling the vacuum line off?

pin14- codes 5, 10 and 11. can you help interpret these for me?

thanks

[Arthur Dalton]

<< Pin 8- code 36 (purge valve) could this have been caused from me pulling the vacuum line off?>>>

It could have , but it should have reset when you put the hose back ON
The purge system has an ECU criteria that has to be met in order to energize.
The demands are :
>80 C coolant temp
MAF sensor quanity spec./ flow range
Engine load condition

When the gas tank reaches 30 ml/bar pressure , the vent opens to the canister.
When purge demands are reached, the HFM module sends are sig to the purge switch-over valve in the form of 5/10/20 Hz.. which hz sig required is determined by engine load input to HFM.
You can feel these pulses if you put the purge in your hand.. the reason for the pulsing is so the engine does not get a large gulp of air to the intake, which would be what you did by disconnecting the vac line..the amount of intake air through the purge is determined by which Hz range the ECU uses, with each having a different time duration, so it is metered.

So, the purge is regeneration/emmissons control of tank venting at a metered pace as to not effect the a/f/ mixture to any large degree.
The most common problem with them is they get full of crap from the canister and they stick either open or closed..each will bring up a code 36 on HFM..a trick/remedy is to squirt WD40 in the valve and the hose downstream [ towards canister]..that allows the engine to suck the fluid through the valve as it pulse, thus cleaning/clearing it from the vac and pulses.

If it is to far gone, replace it, but only after confirming that the ECU is getting an electrical sig to it...



<<>>

You have a bad brake switch and your Throttle cable is sticking or there is not enough slack in it. Lube it and check for slack at the adjuster...make sure you don't have a bunched up rug/mat on the floor near the gas pedal.
On the brake sw. it has been detected to have an intermittant fault and you should just chanage it b/c it will get worse and it is not the brake light circuit that is going bad , it is the other set of contacts that are used by various other systems...so don't post back that " But My brake lights are working fine"..that is not the circuit/contacts of the sw we are concerned with.........it is a multi circuit/function switch with more than one set of contacts.

[SEA320]

Ok, I'll try the WD-40 remedy for the purge.

as far as the cable goes, there is slack at the adjuster end. what do you recommend lubing it with, WD-40?

and the brake switch, where is this located?

[SEA320]

or better yet, a part # for the brake switch?

any thoughts as to why my particular vehicle has 96 engine parts and is technically a 95?

[Arthur Dalton]

Originally Posted by SEA320

or better yet, a part # for the brake switch?

Want me to come put it in for ya..??
Go to the top of the page and look it up.



any thoughts as to why my particular vehicle has 96 engine parts and is technically a 95?

I don't believe it does...........

[SEA320]

could ya? that would be great!

what do you recommend lubing the cable with?

thanks for the help

[Arthur Dalton]

grafite stick or any cable lube....

[Arthur Dalton]

<>

More likely that the '96 [ 210 chassis] uses the same '95 104 engine ..than your '95 124 usinig the '96 engine and parts, because that is what the factory did............your car is the last years of 124 chassis, not a 210 chassis..so you car is not just Technically a '95, it IS one and it is a 124.

[SEA320]

huh, well, it is what it is.

Ok, I wd-40'd the purge valve and it is now ticking away. graphited the cable where I could and lubed the linkages, although nothing was really obviously sticking, there is slack on the cable. also replaced the stop light switch.

after wd-40'ing the purge, but prior to the graphite and switch, the car went into the surging thing again on the way home from work. the additional code from pin 8 was 13, the same I always get when this surging thing happens. I cleared all the codes after the work above was done, we'll see what happens over the next few days. I'm not optimistic though.

What does the code 13 mean exactly? I have changed the O2 sensor and the fuel pressure reg., as well as the coolant temp sensor, cleaned the MAF, replaced the EGR (had a code for that previously). The throttle body is gummed up a little on the edges of the butterfly plate, but not bad. surging is an intermittant thing, once every few days, sometimes corrects itself. thoughts?

[Arthur Dalton]

Well, if you have some Special Version, I would not know exactly how to go about diagnosing it ...My possible remedies are posted with the assumption you have a 124.032 chassis with a 104.992 ebgine

[SEA320]

that's fine, any thoughts to my previous post?