captainOCD

So I'm never one to leave things alone and am eyeing up some porken chips for my blue car (86.5). Looks like it should be quite a nice mid-range torque bump from the dyno sheets.

So anyway, my car currently has 230k on the clock. I've only had it since summer and it had been sitting for about 10 years before that. It seems to run well with only a slight choppiness at idle. It got a timing belt, fuel lines, trans service, plugs, etc all done this summer.

My question is am I asking for trouble if I start tossing speed parts at one of these things with over 200k miles? For sure I'd need to get a fuel pressure regulator, colder plugs, and probably all the cable adjustments.

928S MN

Porken's web site, liftbars.com , has a list of maintenance items he recommends being replaced/rebuilt before installing his chips.

The two items I do not see in your listing are a rebuilt MAF and new TPS. Both of those are critical when going to WOT to insure you are delivering the correct amount of fuel. Without knowing the current status of those two items alone, I would not have installed Porken's chips in my car, let alone someone else's, regardless of the mileage.

captainOCD

Is there anywhere that one can send in a maf to be calibrated/repaired as necessary or are we stuck paying high dollar for a rebuilt one.

928S MN

A lot of folks seem to like Injection Labs for repairing/rebuilding the MAF. https://rennlist.com/forums/928-foru...af-sensor.html

I went thru Roger and got a rebuilt one. As important as this is to a well running 928, I didn't think the expense was out of line at all.

GregBBRD

Aside from the more visually obvious problems that 30+ year old cars suffer from, there are problem caused by age and neglect hidden inside the various components. One of the more common problems we see, these days, is head gasket failures. The head gaskets are made from paper...a heavy duty paper with all sorts of chemical treatments, but paper, regardless. One of the things that makes this paper deteriorate is acidic coolant....and the factory specified that the coolant get changed every 2 years. That was something that was almost certainly not done, while your car sat for 10 years.

Increasing horsepower/torque increases cylinder pressure....which increases the load on the head gaskets.

Will they fail?

No one can predict that.....even with a completely stock engine, they could fail at any time.....or never.

However, with 200,000 miles and 30+ years on the engine, even if they do fail, they certainly have done their job. And what is the worst thing that could happen? Water getting into a cylinder and splitting the cylinder when the engine is cranked over would be the worst possible outcome, but that would be very rare. More common to just have a sudden overheating, over pressure event.

Weighing the risk versus the potential gain is all about expectations and your wallet. If you except to have to rebuild the engine at some point at time and you have the money to do that job correctly, if your accelerate the process of deterioration, does it matter?

Would I recommend that a client do this?

Not hardly.

However, I'm super conservative.

928NOOBIE

Hi

Also I didn't see Crank Position Sensor...it's not tough to get to...but give the allen screw some good taps and a couple treatments with penetrant before you attempt to remove. You may still have a little clean up if the sensor housing itself is deteriorated/one with the car etc but that's easily cleaned out.

the CPS gives the ECU's the signal that fuel and spark should be running...you don't want a failure while driving down the road.
Additionally, the original unit won't be operating as well is it can. When I replaced mine I got an improvement in running quality...

Enjoy.

captainOCD

So sounds like for now I at least need to work on getting a rebuilt maf, new tps, and new cps for the car. I'll work on those then go from there. I'm sure the car will eventually need the motor worked on, but for the moment it seems to be in good running order (bearings and cylinder walls looked good when the pan was off) and I'd prefer to keep it that way.

Otto Mechanic

Matt -

I'm doing this now so I'm about elbow deep in it. I didn't see anyone mention fuel lines so I'll say it; Ken recommends replacing your fuel lines when you upgrade the fuel pressure regulator to the S4 spec, it runs at a higher pressure. You don't want the lines to burst and spray gas all over the engine bay and 30 year old rubber hoses get soft and may have started to crack.

I think he also recommends replacing the injectors with higher flow units? I haven't yet done that. Lately I've been distracted by a coolant leak into the valley of mine and haven't fixed it yet.

captainOCD

The car does have all new fuel lines under the hood. I did see rebuilt injectors recommended on there, but didn't know higher flow was.

928S MN

I believe the 85 - 86.5 MY already came with the 24 lb/hr injectors vs the 19 lb/hr injectors for the later MY's. If this is not correct, someone please comment.

bureau13

This is correct

BIMMERMIKE

I have replaced a few fuel lines but unsure of others. Can someone please post all fuel lines to be replaced.
Fuel pressure regulator to S4 spec is installed as I have Porken chips.

Otto Mechanic

Probably my mistake, my memory isn't as reliable as it once was. I rebuilt my injectrs a couple of years ago during the intake refresh. I'll double check to see if I have the 24 lb version.

Mongo

If you're going to roll the dice and put the EZK and LH chip in, make sure you do everything maintenance wise that porken asks you to do. You can buy 24lb injectors to satisfy the LH chip requirement off ebay. Look for ones that have been refurbished and watch out for the Chinese crap injecetors (they are gray). Part number you should be looking for is 0280150947. I have a set of 0280155715 injectors that flow the same rate. They are more affordable, and I don't expect any issue with using these compared to the Mustang Cobra injectors.