whalebird

Perhaps a skim-coat of antiseize on the threads Shepp...dissimilar metals.
Please do let us know on the fuel pump/pressure/mixture findings. I just did the fuel screen/filter on my car and some fuel lines as well. I was musing the thought that an aging filter or tank screen could draw more amps on the pump and thru the relay. I have some old DME relays that obviously got hot on some of the terminals. Could chronic DME relay failures point to a neglected fuel system? Yes is my obvious guess. But these cars are getting older and the logic chain leading to component failure may also need to be scrutinized. Same egg...different chicken.
I've been looking for a CO meter too. I don't have one but want one badly. IIRC, rus has a LM2. However, I think I could get some useful data just metering the O2 sensor thru a dash mounted gauge. Some people claim this is useful, but i'm not certain it tells the whole story. I would like to set my idle mixture at the AFM but get inconsistent results just reading volts right off the O2. Ideally an original Porsche Lambda meter would be ****. I also like the idea of viewing the mixture changes throughout the drive cycle. This is not rocket science and I know about the wideband O2 and such. I don't want to go to a ton of trouble and expense for a car that otherwise runs perfect. If I'm spending a wad of cash, I'm getting a wireless 4 gas that can be used while driving, ya know what I mean!(?)

dshepp806

Thanks for the advice, Bird...

I will certainly post my findings on the fuel pressure readings (X3) as soon as I gather the data...can't wait to use Len's gauge set,..quality is there, for sure.

Should you find a proper instrumentation piece for measuring CO2 and HCCs (per Porsche spec),..let me know,..geeze,..I'll go half on the cost , with you,....and it can "live" at your place....?????? Sounds like wideband is the way to go (precat, I presume)...lemme' know what you think on this,...I'm not necc'y in to modding my dash for now (as to reading actual AFM lambdas).......BUT would like it to be quantified, at present.....

As to other RL's, we could ship these out to needy RL's...to show the kindness of humanity....naturally...

Lemme' know Ace,..we could half our costs and double our efforts,..not to mention helping many other RL's.........Have you a wideband product that tops your list?

and lemme' know about the RUSH show (needs),..hehehehehe.

BEST!

Doyle


BEST!

Doyle

dshepp806

Speak to me of this "wireless" approach,..sounds very interesting (pardon my ignorance in the automotive world)..

Doyle

whalebird

http://buy1.snapon.com/catalog/item....re&dir=catalog

By wireless, they mean handheld I gather. No photo in link, but I have seen one and they are compact and well made. Gunson for $250 is probably the deal.

KNS

My DME relay gets warm while driving (not hot). Is this normal? Also, the previous owner of my car replaced the fuel pump a few thousand miles ago, the car has got about 106K on it now. I believe the DME relay in there now is the original, and yes, I carry a spare (KAE I believe).

The tank screen is on list of things to do...

dshepp806

I wouldn't really know about how warm mine gets (honestly).

I definately replaced my screen with a new one,..dhipped my perfect looking original one to a fellow RL friend in Australia.....

Tank was good-2-go!


BEST!

Doyle

rusnak

I have "short attention span" syndrome when it comes to wrenching projects these days. It's not so much me, as it is my schedule. I have to move on before I can complete anything anymore.

I have been meaning to check the fuel tank screen but never have.

I have the Innovate LM-1. I never got the data logging to work, and the CD-ROM never worked. I am happy with just reading lambda % while driving down the road. It's super interesting to watch the mixture go full rich when you floor it.

rusnak

I'd say warm is ok. Hot is not. Try switching out the spare and see if there's a difference. I carry two spares, lol.

theiceman

its gonna get warm. its carrying fuel pump current.

whalebird

which is my point as well. If there is a log jam in the fuel supply like the tank screen upstream, or the filter downstream, amps have got to pile up in the circuit. I thought that a fuel delivery volume test would be the tell-tale, but the Bosche pump is very hearty(compared to cheaper knock offs) and has enough headroom to flow in the presence of a slight restriction. Which brings us to the discussion at hand: does the relay have the same 'headroom'? The discussion of amp rating of the various available relays may be very relevant to the condition of the fuel filters (especially the screen that has been overlooked since these cars were new, but now that they are so much older...)
If your relay is hot, (warm would be expected) then I bet your pump is hot too. I can see a variety of downsides to this condition. Hot fuel is bad, some of you may be familiar with the fuel coolers on Mercedes cars that use the A/C suction line as a means to cool incoming fuel.
I can't count haw many of these various car (CIS/motronic especially) get a 'noisy' fuel pump in hot weather when fuel pressures and flow spec out as they should. All the while, many people will say this is normal, myself included-as some fuel pumps are noisier than others, but now I'm thinking this could be an indicator of fuel flow restriction. I think it's prudent to make sure the fuel suppy lines from the tank to motor and back to tank need to be replaced(are the old stock fuel lines rated for ethenol mixed gas? are new replacements?)
Something to think about, no?

KNS

Hopefully all new replacement fuel line supplied by Porsche would be Ethanol friendly.

Lorenfb

"If your relay is hot, (warm would be expected) then I bet your pump is hot too."

A simple resolution to the issue would be to use an ammeter and measure
the actual current. Ideally a clamp-on ammeter would be perfect. The pump
current should be between 7 & 10 amps. Bad pumps or excessive loads
would cause 15 to 20 amps on the high end.

dshepp806

Fuel pump pressures were 30.7 PSI while idling......It kept a residual 32 PSI for over 45 minutes. (((I would note that I loaded a fresh fuel pump about a year ago,..reworked all hoses down there...she has new fuel lines throughout the rear from about 2 years ago......and changed out the FPR about 6 months ago...Did not replace the FPD....)))

Removed and cleaned the ICV and all related hoses. Installed a fresh throttle adjustment screw and O-ring,..with light oil on the O-ring and light antiseize on her threads....The old O-ring wasn't cracked or broken but has surely shrunk a good bit....the old screw had a VERY small amount of play in it when you grabbed it and appied pressure L/R.....the new one DOES NOT! New new O-ring looked a bit FATTER!!!!!!!! It's quite tight

Disabled (centered) the ICV and adjusted until I see 880 RPMs,..removed jumper,..everything stayed put,..

Had PP ship 2 KAE relays for a Sat delivery,..so I installed one right away.....

Adjustment was textbook,..all was and is smooth as silk...and at spec.....SO,..IN goes the new yellow throttle screw cap!!!!!

Although I have no time to check the pump's current draw,..that will be next on the list, just for datapoints...no time to snapshot the DC voltages on the O2 sensor, as I've a new Bosch one to install....Lastly,..to get the damned mixture checked.

Funny to see the outside of the KAE relay read "Made in Germany".....while the guts (potted, no less) state the origin of the composite relay,..THAT being Malaysia (ain't gonna clean no contacts in that baby). I've attached a super crappy pic, of both the removed relay innards and the removed throttle screw....will be glad to get my damned camera back soon!!!!!!!!!!!!! I'm sorry (again) for the blurry pics....this flip phone isn't good at any close ranges.

These KAE relays are rated at 30 amps....(unlike it's Porsche brothren at 15 amps,..mmm?)

Purring like a kitten !!!!!!!!!!!!!

Rusnak/Bird: this fuel gauge from Les is great,..let me know if you guys need to borrow it...

Best!

Doyle

whalebird

That's my approach too Loren. A quick clamp-on ammeter at the pump leads could tell a lot, and may be a good idea in any instance of a major service. Perhaps before and after filter replacement to "see" whats inside the filter(S) or going on with a pump combined with other tests.
As for OEM fuel hoses: one would hope they are manufactured with the latest technology, as they are made to Porsche's 25 year old specs, or have been on the shelf for ten years one may wonder. I am vaguely aware that there are ISO/EPA regulations that dictate to manufacturers what minimum standards are for various components, certainly fuel system components. One would hope the new parts are compliant IF so dictated.

dshepp806

Think I'll go get myself a clamp on for my fluke.....I hate having to disconnect things.....can't find my original clamp set.....

My question still remains, gents: and that is the inquiry as to how the pumps behave with various (resultant) voltages to it's terminals (regardless of where the voltage drops could be occuring). I'm not speaking of any obstructive flow issues,..just voltage supply levels to the pump. What is the relation of the pump's output relative to voltage input?

The last thing for me to do (aside from quantifying a year old [NEW!] pump's current draw) is to gauge the performance of what's left:

1.) Maybe someone can give me a cliff notes on the Fuel Pressure Dampener's function,..and what could be symptomatic in it's failing performance. Since I installed a new Fuel pressure regulator about 6 months back,..it would seem practical to replace the ORIGINAL damper with a new one...making the system new again.


2.) Get those injectors out for flow testing and rework (if needed)...I've no records of this ever being done by the PO....I bet it's time...even though she's running great,..

I'll never know if there's some compromised performance unless I quantify the elements (I figure)...I don't call this "throwing parts at something",..instead, I call it "replacing 24 year old parts" !!!!!!!!!!! Quite preventative....

After completion of these items: I gotta' tell ya,...the fuel supply/injection system, top to bottom, will be in perfect working order!!!!!!!!!!!!!!!

BEST!

Doyle