mskar

Yeah, a couple of dozen $100 parts here and there start to add up! My other go-to hack is epoxy resin and cloth repairs on things like cracked inner door panels and wheel-well liners.

I never kludge brakes or anything with the potential of fire (Fuel lines, ATF lines). Also there's no getting around a TB/WP job on an interference engine but I think you're good there since yours is an early car and non-interference.

Take every bit of advice you can get on the forum its a GOLD MINE!

dr bob

Guys--

Keep in mind that these standard AMP-style connectors are, well, standard connectors with readily available replacement pieces, including pins, contacts and shells both male and female. Not much need to kludge damaged connectors, In fact, since these are critical to the car running, I'll go out on a limb a bit and suggest that it's a Bad Idea to do so.

My too sense...

mskar

Silly question, and I may have missed this, but have you replaced the fuel and air filters since it's been sitting? You're going to replace them at some point anyway why not now. Any new-to-me car I work on gets cap/rotor, air filter, and fuel filter if its been sitting.

You mentioned running fuel injector cleaner through, there is a big difference in fuel injection cleaners, some are nothing more than ethanol. I use 44k, I've heard Techron is good, maybe others can chime in with their recommendations.

Also, I'm unfamiliar with your particular fuel injection but I've worked on lots of Bosch systems over the years. One of the resistance values on the AFM should be a range of resistance as you operate the barn door through its range of motion. Its basically a rheostat and they can develop flat spots or intermittent faults where the wiper-arm carbonizes the track it rides on. If there are Idle and WOT switches, test them from the electrical end to make sure they are closing and opening when they should.

Some other random thoughts on fuel injection
- back to basics: verify spark, fuel, compression before delving into the long process of diagnosing FI
- Temperature sensors are usually absurdly reasonable and worth replacing if at all unsure
- O2 sensors (if equipped) are not even remotely reasonable but when bad will cause rough running, as will exhaust leaks before the o2 sensor
- fuel pressure regulators and dampers can degrade internally and dump unregulated fuel into the intake. If they're vacuum operated, test the vacuum side with a vacuum pump. You can test fuel delivery at various points in the system with a fuel pressure gauge according to the manual as well.
- just as guessing and replacing parts gets expensive, buying every possible tool for diagnosis is too. Your friendly local auto store may have a loan or rental program.
- start with the easiest test first to maintain your sanity and save you time
- Never get complacent when working with fuel. It hates you and wants you dead.

Search this forum using google appending "site:rennlist.com inurl:928" to your search, ie:

weak spark site:rennlist.com inurl:928

I forget which saint posted these search modifiers but they're a time saver!

mskar

I did a quick search and these connectors are $3-$4 a piece. Maybe its time to fix the end of my knock sensor properly.

Landseer

Chuck, I've probably got a good spare used thermo-time in a drawer here that I can send to you gratis. It drives the cold start injector. PM me your address if you want it.

Keep up the good work, its great to see another one of these cars getting back onto the road. You are on the right track. Please verify where you got the replacement injector relay and that you got exactly the right part number.

Prior to replacing, did you happen to try to start the car by applying a three-way jumper to the injector relay slot, linking 30-87-87a?

Did you access those grounds on the passenger cam cover yet? Those are for the engine electronics and are critical. There are 2 of them, one located just above the "O" in "Porsche", the other above a point between the "C" and "H". The one above the "O" is pretty much completely hidden beneath a valve on the USA version of the car (for the emissions air injection system ). That valve has to be removed first. It is easier to accomplish than it looks!

BTW, there is no ground wire to hunt back in the valley on a 1984 car. Engine electronics were grounded in the back of the valley beginning in 1985, not 84.


I'll link a thread, the first few pictures of which shows those grounds. Note that the thread rambles and shows some things your car doesn't have like CPS crank position sensor (the gray car is an 84 euro with a different kind of electronic injection system). But lots of other stuff is the same.


Also, there are divergent opinions and some best practices on topics such as cleaning contacts (deoxit is best, I've been using dremel wire brush though) and fuel line selection ( best are the expensive but impressive solutions from Greg Brown; I've used specific hoses and clamps and accept the risk).



http://forums.pelicanparts.com/porsc...-16v-euro.html

Its been a while, but here's one where I replaced injector hoses on my 84 USA car:

http://forums.pelicanparts.com/porsc...placement.html


I have a pretty well sorted 84 USA in the driveway. Can snap pics as needed of details.

Finally, maybe somebody will link the work treatises of Dwayne. He's produced some tremendous detailed refresh threads. His first car was 84 USA, so he has some really, really good procedures for certain subsystems. Gas Tank. Brake rebuild ( very easy on 84). other stuff too.

Chucks928

So, On Monday I ordered an injector filter kit from Mr Injector. It seemed that my problem was narrowed down to fuel starvation and the filters were the culprits. I was outside poking around on the 928 today and decided to reclean a few ground spots,the ones on the passenger side cam covers to be exact. It couldnt hurt to double check everything before jumping in on those injectors. I cleaned off the grounds and was double checking for bad connections or leaky vac lines when viola! I noticed on the passengers side of the throttle body what appeared to be a recessed plug,just below what looks like a cap. So I squeezed my hand in there and poked a small screwdriver in there and lo and behold theres nothing there! And there is remnants of old RTV all around the outside of it. So for kicks I manage to stuff the end of a rag in there and try to fire the car up....nothing.
A little fuel down the tb and it fires right up! And,though the idle is running high,it runs smooth and needs no help. I let it run for about 5 minutes and it seems to be fine. I shut it down and restart it 3-4 times and no problem.
Then I popped it in reverse and it shifts easily from drive to reverse,but.......

It starts smoking out the exhaust like an old locomotive!! I mean REALLY smoking! White smoke and steam..Damn! I shut it down and let it sit for a few minutes.Then fire it up again and it idles easly at 1500rpm with very little smoke. After emailing my friend Wayne he says I may have loaded up the exhaust with fuel and moisture from all the attempts at keeping it running with that vacuum leak. I let the car sit for a couple hours and it fired up no problem and idled right down at about 750 RPMs.....backed it up and down the drive with no smoking issues! So I may be very close to a running 928!

Now the question..what is that open port? Should it be plugged or is it a vacuum source for something? Right now its plugged with a rag corner but I want this fixed properly. I added a pic....any thoughts?

Mrmerlin

there should be a diaphram on that port,
at this point i would make a plug and JB weld it into the hole

Chucks928

Heres a pic of the same port...passengers side of the throttle body..I have a long screwdriver resting inside of it to identify it... It must have been a vac source for?
I also see that the main vac line coming from the front of the intake is cut off and plugged..thats the hose in the lower right corner that curves downward..its plugged shortly past this pic.

Majestic Moose

You are missing the decel valve. Cap the ports or replace it.



The hose from the front of the intake goes to the A/C idle valve hanging from the crossbar.

Chucks928

Thanks guys! Sounds like its not a major component so I,ll plug it for now. Looking around I found what appears to be a homemade plug rolling around on the windage tray below. My assumption is that somewhere along the line the plug was put in to replace that valve and when it fell out,the gentleman who owned the car before me could not figure out why the car wouldnt start so he decided to sell it. It seems to run fairly well now,other than the cold starting issue which I,ll work on next!

Chucks928

And just a extra note....I downloaded the 82 owners manual and it states that the Decel valve ( Vac limiter) is only used on manual tranny cars. Mines an auto,so it gets plugged.. Just some fyi!

Chucks928

Well,now that the weather is finally breaking here in the East,its time to peck away at the 928 and get it up and running. This week I got around to changing the plugs,the dist cap and replacing the Temp 2 sensor. The plugs I pulled looked pretty worn and showed signs of running rich which I suspected as it does smell like its running rich at idle. The Temp 2 sensor didnt fix the cold starting issue but the car does seem to run a lot smoother with the sensor and plugs installed.
Sooooo...as of now..here is where it stands.
Still wont fire on a cold start,but... if I crank it...let it sit 15-20 seconds,then crank it again,it does attempt to fire.If I repeat this 4-5 times it will fire up,but will run like crap. If I just hit it with a little gas down the TB right off,it will fire up and run,but will idle around 1000rpm.Idles high but runs smoothly.
Once it has fired up, I can let it warm up,shut it off and it will start right up with no help.
I finally took it for a short run down the road..she shifts ok and at idle throttle runs good. If I try and put my foot into it a little too much it will stumble and stutter, it may be starving for fuel.
So, I,m slowly getting there,and I think my next step is rebuilding the injectors. I have the rebuild kit,just waiting for a warm day to do it. This 928 has been a learning experience for sure, but when its finally all sorted out I,ll have a good grasp on whats been done to it and will have some knowledge to maintain it down the road! Any thoughts or suggestions are always appreciated.

VanD

Chuck - somehow I have been asleep and missed this thread until now - as noted I'm in Rochester (Pittsford, actually) as well - have to get together someday and check things out - maybe with Hinchcliff and do a C&C- feel free to PM any time and exchange numbers.

BTW If I were you I would replace that green wire ASAP - it will save you much grief now and later on - I have a couple new ones if you don't want to wait for shipping. I'm around most of the time now that Hockey season is over and I'm 'retired' so have time when the kids aren't around. I also have a manual set if you need to borrow a hardcopy or make a copy of what you need.

I have a few that are in the same stage as yours so could always use a hand as well.

Chucks928

Van, thank you for the note! PM sent.

Chucks928

Just in case anyone is curious...heres a pic of a bad green wire and a good green wire! Thanks to Wayne Strutt and VanD and the countless others for insisting I replace mine. It hasnt taken care of the cold start issue,but it does seem to run a little better and idle down a little better than before.