Decided to take the plunge and do an intake refresh - using David Chamberland's excellent guide. Status so far:

Intake off
2 broken injectors (fragile little suckers)
1 broken Bosch connector (still usable, but frustrating)

Got a few things I am stressed about, not sure if I have to tear deeper into the car to fix:

1. Coolant in the intake valves - 2 of the bolts that had to come up in order to release the rear intake bolts had coolant in them? Apparently a resivoir of some kind. Sealed them up as quick as possible, but some leaked out and apparently got into #8 intake. The valves were closed, and I vacuumed out the intake, but do I need to be really worried about this?

2. Oil in the intake valves - the rubber gaskets obviously need replacing on the intake, because oil has been seeping into the intake, particularly in #1 and #2. You can see in the pic I also had a nice little pool of oil in the bottom of the throttle assembly - this can't be good I imagine...

3. Grimy injectors - is that typical? I am sending the unbroken ones out to be checked out, I just wondered if it is typical to see them so grimy and dirty.

4. All of the intake valves are in a closed position except for #7 - is that bad? I posted a pic of that too - should they all be closed if the engine is off?

As always, any guidance from the experts is appreciated...

Bill

 

Did you use the special tool the guide recommends?

What broke? The plastic connector? Or the insulation?

If these are the bolts that bolt the bracket for the fuel damper and regulator then you have no issues. Those bolts go through to the water jacket. Remember to get them tightened back as you go or you will leak coolant. Also, expect to need to top-off with a little coolant to replace what spilled.

Actually, it's pretty standard. The oil is coming into the throttle-body via the oil breather hoses. The amount of oil you show in the t-body is more than I've seen before - but not more than has been reported before. I would suggest a few thread searches to find similar occurrences and their causes and fixes (if any.) 928s ingest oil through the intake - period. Some more than others.
I assume that you've checked and that the coolant is free of oil and that the oil is free of coolant? Is your oil consumption normal? If so then it's nothing to lose too much sleep about.


Yup.

Just the unbroken ones?? I assume that the 'broken' ones are broken because you cracked the yellow caps? If so, the shop to which you are sending the broken ones should be able to fix them. I'm not sure what you are planning on... but...

Marren Motorspors (and perhaps Cruzin) will clean and balance the injectors and replace the o-rings and broken caps.

Was the car running right before? If so then I doubt you have a problem. The intake valves only look really open when they are fully open. You could use a 27mm socket on the front crank bolt and rotate the engine (clock-wise!) through two full rotations and watch all the intake valves.

 

I think the little yellow fuel injector caps are called "pintle caps". Mine were carcked too, but cruizinperformance.com replaced them as part of the service.

 

Stress out later. those valves look perfect, clean with no deposits. If you had a timing problem, the car would not have driven into the garage. Stuff some clean rags into any runner with open valves so that nothing gets into the cylinder. That is the only thing you have to worry about right now, and it is crutial that nothing gets in there. Looking GOOD !!!

 

I used some yamabond on the water jacket so it will not leak next time I have to remove the intake. I sent my injectors to cruzin perf and when I got them back I noticed it came back with the old lower seal installed. Rich said that is unique o-ring and he does not have it in stock and that I needed to get it from Porsche (BUMMER!, Big 3 sells in it a kit and cost about $5 for each injector). When you reinstalling the injector be sure you connect them to the injector rail first (this way you know they are sitting properly in).

Good luck,

 

Thanks everyone - especially for the encouraging replies As you all probably well know, it can get a little frustrating working on these machines...and it is a little scary to have your whole engine open up in front of you for the first time...

Dave - to answer your questions:

The drivers side knock sensor was the connector that broke. I didn't have the Bosch Connector (order now in progress!), but I had good luck with a couple of small screwdrivers for all the other connectors. With this one, the plastic was just too brittle. The actual connection still works, so I am just going to have to zip tie it to keep it snug I think - so on the whole, not too bad.

The two injectors broke when they slipped out of my hands while disconnecting them from the harness (again, would have been facilitated by the Bosch tool). The ceramic ends on the injector end cracked on both of them - I didn't know that those could be fixed, so I will send the whole set out to Marzan or Cruzin for cleanup and repair. Anyone have any recommendations between the two?

As for the car running right, this one seems underpowered when compared to my other, and I had an erratic idle. The engine was running smoothly though, so I doubt I had a valve problem? I think the idle is related to the flappy valve, which I am replacing, and I am a little suspect about the injectors - they were so grimy I am wondering if I was getting full fuel delivery.

Anyways - I will keep you all posted. Dave, Masco, Daniel and Giovanni - you guys are AWESOME - thank you so much for the tips and encouragement! I owe you all a cold one...

Bill

 

if you're worried about dirty injectors here are mine.
Looks can be decieving becasue most of them performed at better the 95% when tested by cruzin'. The cleaned them up, ready for install. Not quite sure where the 8th one is in the after photo.

 

Bill,
I'm in that engine area as well, since you've got the idle speed actuator in plain sight, lubricate the heck out of it, unless you're replacing it as well. Check the vacuum connections as well; my '87 has 101k +, and several of the elbows have hardened, cracked, and even fallen off their vacuum ports. Check 'em all out, as I'd hate to hear you had to re-disassemble your intake.
Check out my "Uh Oh" thread.....

My intake tract seems much cleaner than yours, luck of the draw???

Look at your knock sensor insulation, both of them. Someone stated that if the insulation is disintegrating, electronic "noise" can cause a 5 degree loss in timing? I'm outright replacing my knock sensors, as their wiring lead plugs are disintegrating in my hands! And, of course, the insulation is long since falling off.... Little of it left!

Someone else I know, who is a mechanic by trade, particularly told me to clean off the grease ring, that will be around both sides of the throttle plate ( butterfly ), in the throttle body, in the closed position. OH, BOY, was he right! YUCK!!!! And while you're cleaning out places, that grime I see in the bottom of the connection between the MAF and throttle body, in your pic, should be removed, before it has a chance to come loose, and continue on through the engine......

Just my thoughts and observations....

Oh yeah, I seriously doubt the flappy valve has anything to do with the idle circuit..... But, while you've got the intake off, if you have a mighty vac, can you get the flappy actuator to move the flappy? Mine is sticky..... It may also have a grease ring to be removed as well......

 

Marren motorsports does have the unique o-rings and will do it all. They are AFAIK, more expensive than Cruzin' though.

 

If this is the knock-sensor side connector then I would just replace the sensor. In fact, with the intake off if the knock sensor's insulation shows signs of deterioration then just replace them. The knock sensors send out a weak and complex signal that is very susceptible to noise and ratty insulation will allow noise in. If your knock sensors look anything at all like to pictures I posted above then I recommend replacing them.

Yes. Do that. Send the whole set out. When they bench test the broken injectors they might be able to determine of the cracked connectors will cause a problem.


I've always used Marren. They are in New England though and therefore close to me. I've never had any problem with them and they can get all the correct unique parts for the Porsche injectors. Cruzin' is less expensive though.

 

BTW, Bill, buy some fender covers. Less than $200 (IIRC) and they will save your fenders from scratches that WILL happen...

 

Hey Dave - ordering fender covers, Bosch tool and a flappy valve today from 928 Specialists - learned my lesson!

Brett - thanks for the tips - I definitely want to get as much replaced there as possible - definitely don't feel like going back in unless I have to. I don't know why my intake seems so dirty - there is a LOT of oil around - especially around the intake gasket areas. I don't know if there is a top end oil seal I can replace, or if it is just the nature of the beast. I am sending out my injectors today, so I hopefully can start putting things back together ASAP.

Bill

 

Bill, I got my threads confused. Below is a link to the picture of toasted knock sensors:

https://rennlist.com/forums/showpost...3&postcount=11

 

Some of the oil might origin from the oil filler neck which is known to often leak.
Make sure to replace the gasket on that while in there.

Cheers/Peter

 

Hey Dave - if the other side of the knock senso connector is broken, I guess I just need to work on fixing the connector as it is part of the wiring harness, correct?

Bill