Newb 944S LS1 Conversion

Gutterboy wrote:

my fuel pressure seems stupid high at over 50psi and stoker don on youtube has seen all his rough idle and backfire issues disappear after adding a regulator. may need to go there....

You need 58-60 psi on the LS system. If using the corvette filter/regulator, be sure you use only an AC Delco or Wix brand filter. These will handle high flow fuel pumps without any issue.

I'll report back after I fix a leak I have that ray has been consulting me on a couple missed steps I made on the fuel return side. I have Kent's full fuel kit with whatever filter came with that.

been lettting the smells of handprints and spilled fluids burn off the car a bit more. Verified that I have 58 psi at fuel rail.

Big thanks to Ray on helping me find my issue by mistakenly using an AN6 to ? fitting that DID NOT have the 8mm ISO bubble flare which caused a seeping leak on the return to the tank. Ray was also right that with the 20L of fuel i started off in the tank for first start that although i rigged up a drain hose setup to my gerry can, it only dribbled may 100ml or 150ml of gas and then stopped so return is most likely higher up. anyways, re-used a piece of the hardline with the proper matching iso bubble flare and put one of the leftover compression fittings i had from kent's fuel kit (telling sign i did it wrong lol) and all done there.

found my crank sensor harness was trying to melt on the exhaust so pinned that back after inspecting but seems to be just mangled, didn't burn through wires.

Been working on trying to get power steering to stop whining on turning. Lifted car and did lock to lock 10 times seemed to do quite a world of good. I think i might need to do it again with the reservoir even higher so its definitely above the hydroboost to do lock to lock on steering again to make sure any air gets out of the system from first fill.

Lastly my clutch is too high of a friction point for comfort. I dread having to unclip the assembly from under the dash cause i have a feeling it could be next to impossible to get it to go back on now that i have hydraulic pressure from the system being filled and bled.

do i need to purge all fluid from clutch pedal to be able to disassemble and undo jam nut to then thread the yoke down the threaded rod to shorten up the pedal throw and get the friction point to the floor? Doesn't seem like i can adjust while all assembled. And i severely doubt i could get the yoke back in line with the pedal while fighting the red clutch spring and the pressure from actually pushing in the pressure plate fingers with the throwout bearing. with the clutch fluid evacuated this would releive the tension since air would just compress and wouldn't push in the pressure plate at all.

by now i think i am speaking rhetorically and the only way to adjust is the messy/spilly backbreaking way i have explained? by the way i have kent's modified tilton

Clutch woes in previous post are a matter of preference for drivability so not an inspection concern.

One thing that does puzzle is one checkbox that says "neutral safety switch operation"

I remember my car even before the original 2.5L exploded was able to be started in gear so I had assumed that it never had this feature. But I have no idea if that was previously defeated and whether this something I need to hunt and get hooked up somehow?

Can anyone let me know whether this feature truly does not exist in a 944? Mine is an 88 944S.

Only the later 944’s with automatics had neutral safety switches.

Thanks Bob! That makes that requirement easy! Lol

after having a preliminary discussion with an inspector for the out of province inspection i need to get done since moving the vehicle back and completing the build; i took each wheel off and verified measurement of the pads at 8mm. From what i see of new hawk pads at .685" it looks like i have just less than half a pad? left all the way around on inside and outside. Thinking that should be fine for a pass since the big book for the 200 some point inspection says reject if less than 1.6mm.

verified my headlight washers and windshield washers all work with that final fluid added, odometer works, and so does horn.

My only last concern and not sure if its an issue is the following:
when driving the car under low speed and large steering swing there is minor power steering whine. I've jacked up the car twice now with 10 slow lock to lock turns of the wheel to make sure any air is out of the system.

It doesn't bother me but not sure if its an issue or not for purpose of an inspection? thoughts? is this normal or no?

still have to do one more bleed of brakes all around and decided i'll mess with preference of clutch height after its legitimized for the road.

any help or insight on power steering would be appreciated.

Hydroboost on these cars tend to have a little whine Recheck all of you hose connections, especially return lines. A very slight leak can cause more whine than normal.

been hunting my hose connections like a hawk after several small short runs of getting it up to temp. No red anywhere and the level in the reservoir is solid with no changes anymore.

It used to whine alot and then when i finally got less distracted with other things to check and did the couple sessions of slow lock to locks the whine has now largely subdued to an occasional "little whine" as you describe that you honestly have to concentrate to notice.

Looks like i got my confirmation of that system being "normal" for these conversions. Awesome how so many checkmarks have come in all at once.

just gotta finally mount the ECU to the floor with a modified mount for the shape of the ECU and hide my stereo wires that i failed to diligently install eons ago.

figure out the lowdown on insurance and get a test/demonstration permit to take it to the vehicle inspection appointment. Exciting to almost get this Vorsche 948 legal!

Great read, glad you came back to the project after the intermission it's turning out nicely!

been following ray a lot cause he has incredible detail and great insight to all the questions many of us have but other writeups or discussion may leave a person wanting on how/what/why/where and what/how am i doing this wrong?

anyways here's a link to catch up on where he's at that got me asking more things...

[You must be registered and logged in to see this link.]

last night i got ambitious and got upside down with both arms in front to undo the jam nut (on a 7/8 tilton you need a 1/2" wrench for this; perhaps this saves someone crawling underneath their dash 3 times before getting the right size in realizing that "oh yeah this is a conversion part and therefore imperial not metric")

shortened the length a fair bit after much fighting with needlenose pliers that had a oval'ed out section with gripping teeth which worked perfect for gripping the smooth end of the pushrod shafter after the threads. Had to push and shove to get that firewall grommet out of the way for my pliers to get on their but finally got pedal engagement where i want it.

Was never worried about firewall too much cause i installed a firewall brace on my new clutch master for good measure. Also i was able to fully engage pedal to floor in its previous setting but its just so much better and the way it should be now. I don't think i was slipping before because even though it grabbed high i still had another 2 inches of travel after the friction point.

i did undo the return spring tension a bit just to help and all seems fine but i think i am going to do another quick bleed just to make sure. I need to re-bleed al brakes as well just to make sure its tip-top.

had my appraisal yesterday so i can get insurance hopefully today and if all that lines up i can then get my first 7 day testing/demonstration registration permit to fully try it out on highway and roads around town. Also can then schedule my out of province inspection and go to my first car show with it this friday/saturday! here's hoping everything pans out!!!

forgot to mention one other thing; i have a small puddle that developed under the car and its a strong smell that i can't identify but appears to be colorless and dried fairly quickly.

definitely not fuel, not power steering fluid, not brake fluid, and i have zero wet spots under the car to identify what this is.

doesn't seem to be coolant and i have no coolant leak but when i did have the coolant leak it did fill the bottom runner which had been seeping from general inertia of the car. But this doesn't add up cause it's from the exact middle of the car and that runner is on the driver's side and its no longer wet anymore as i cleaned it up with brake cleaner and what not. I have no idea what this wet spot is and where it's coming from. Might try and see if i can reproduce it and see where it is developing from. Strange.

By chance, did you have the engine running shortly before seeing the wet spot? If so, it could have been condensation dripping out of the exhaust.

i did have the car running just previous to noticing this but it's right in the middle of the car and my exhaust exits at stock location so on driver's side. doesn't really match up.

also i wouldn't expect exhaust condensation to have that strong of a smell.

little spooky but no drips from underneath my lift anywhere.

It can come out of a header gasket, exhaust clamp area, and a small pinhole in a weld. It would have exhaust gassy smell.

so ran the car last night to get it up to temp and then backed it on to the lift and immediately put it in the air to watch for this previous puddle to magically appear....

absolutely nothing.

now i have a theory but i think its weak cause the puddle being in the center of my two platform ramps on the lift doesn't line up with what i am thinking below.

i have not completed the AC system as my preference is to drive it to a good AC shop to take my old porsche firewall ends and properly braze them to new flexible lines to the crazy place that i hid the dryer unit before it goes on to my new condenser and then on to the compressor and then from compressor to second port on firewall. Hopefully he doesn't shake his head too much when i show him the job i need done lol. gonna be tight to get those fittings on that dryer for sure since i relocated my coils there as well and popup headlight motor is doing no favors for access either.

Now in the meantime i fashioned some rubber plugs (one i had to modify severely for it to fit in the smaller hvac port) to keep these open holes from getting contaminated until the AC guy can complete this.

my thoughts are this. the fluid was very watery and had almost a strong ether type of smell, i couldn't put my finger on it but didn't smell like fuel, exhaust with either a rich unburnt fuel or sulphur smell.

my theory is that maybe when the appraiser was checking all functionality of the car to assess condition for me to try to get insurance (long story here on why this had to be done), is that he may have pressed the A/C button and perhaps the venting in the firewall burped out some old refrigerant that since exposed to atmosphere ended up as some condensed mixture with remnant refrigerant in it.

pretty odd that i can't get this issue to reproduce itself. so maybe not a problem at all? lol

went back to playing with clutch free play and engagement for proper pedal feel. got it nailed now and even pulled off the bottom of my 2 piece bellhousing just to make sure i am happy with how it is engaging and disengaging. Man, sure would be annoying to only have a 1 piece bellhousing. Really annoying for future conversion folks that you can't get the 2 piece one to be able to inspect your throwout bearing play and such. If faced with that i'd be tempted to have it laser cut to be a 2 piece but the bigger problem is that you don't have all the threaded holes for the bolts to make the 2 piece one again so i doubt laser cutting the bottom half for inspection purposes gets you anywhere. Beyond glad i have one of the old 2 piece bellhousing's. i'd imagine these are pretty tough to find now.

seems like a major heat stress of letting the car run continuously tends to find leaks that didn't exist on firing it up the first day.

had a bad seep at the transaxle stiffening plate and i think i have that largely narrowed down to the one bolt that doesn't go into a pocket in the casting of the transaxle and is exposed. Was getting gear fluid down the threads of the allen bolt. Epoxied the end of the bolt and took care of most of that. (should have done gasket around that bolt and not just around the outside)

the next one was making me lose sleep at night. was getting a small sweat at front of oil pan, but after investigating ALOT, i noticed the sweat had the appearance of little daggers which seemed to show that was a high surface tension fluid. on feel of the fluid it was watery and not gummy or viscous like you would expect engine oil to be. Traced it back and found a couple of wet drips on the furthest back collectors off the exhaust manifold so apparently i have a brake fluid leak with hydroboost. This is rather annoying cause i had all of this tightened up perfectly and all my fittings are good and dry.

I must have something either not clamped equally or tight enough for the brake master cylinder to the hydroboost. Clutch master is not the problem as it is completely dry and after doing many pedal presses to hunt for this there is no issue there.

The wet spots seem to be on the underside of the hydroboost cast assembly which is mistifying me cause other than the cast black bolts (which i have not touched at all) there is really nothing to tighten. The adapter block from brake master to hydroboost is good and tight and no signs of fluid on that at all.

i have a feeling i have to pull my coil relocation bracket off to get better access, drain the reservoir, pull the reservoir off, and just start going over all of it again. not sure what the torque spec of the big 22mm bolt with the copper washer that holds the shiny metal manifold for the power steering in and out lines to hydroboost but i have it good and tight and besides that would be leaking power steering fluid if that was the problem not brake fluid.

tough one to hunt down. alas since i thought this was an oil leak i already did a useless bead of jb weld and epoxy over top of my gasket sandwiched between the block and the champ oil pan. oh well doesn't hurt, just looks uglier now lol.

GB,

I suspect the grommets that seal your brake MC reservoir to the MC may be the culprits.  This leak would natrually run to the back and perhaps drip off the Hydro-boost housing.

Did you ever remove the reservoir from the MC?
Did you replace these groumets?
If replaced, did you install them in the MC 1st before inserting the reservoir?

Double check the interface between your brake MC and the reservoir.  I know it will be hard to access but try probing with a dry paper towel twisted to a point, and do some poking around in that interface area.  If it comes back "wet" then you found it!!

Good luck my friend!

Thanks Ray!

So when i originally pulled my reservoir to clean all the old cruddy set up brake fluid gunk in the bottom, the grommets remained in the master cylinder. never did pull them out that i can remember and when i reinstalled i definitely just pushed it back in.

gonna pull my coils out of the way to get at it and hunt around and check there specifically.

Might even be a good idea to run the car to temp and then disassemble and then do some brake pedal pumps with everything out of the way and nice and warm to see if i can find where its pissin out.

if i didn't exactly the reservoir seated in properly its quite possibly that's where it squishing out and honestly that would be the place i HAVE NOT been looking nor is it easy to look for with everything else i have in the way lol.

GB,

The brake MC reservoir is a low pressure vessel so there will no squirting from the interface with the MC when the brake is applied... just a constant drip.  Recall there is a quasai open fluid level float valve in the cap.

Before you take the MC apart and disconnect any lines... check for an interface leak.

If it turns out to be the grommets, the fix only requires draining the reservoir and removing the Hyraulic feed line for the clutch MC.  ...and a bit more bleeding of the lines.

grommets on master cylinder were bone dry on inspection.

after another drive and took some logs this time with my hptuners MPIV device or whatever its called, and then put the car on the lift to inspect again and noticed a darker fluid droplet on the steering knuckle and then that combined with droplets on bottom of cylinders 5 and 7 ports of exhaust manifold i'm thinking i may have already sealed up my previous leak on the adapter block from the master cylinder but this issue still remains.

on one of the drives i had i was leaving some crazy big trails of blue smoke, but it doesn't smoke blue at idle and nor has it since. engine sat pulled from previous swap since 2010 before it received 3 drill pump treatments in the 6 months prior to coming back to life on june 17th this year.

i also have a p0801 code for reverse inhibit, i'm guessing that's something i just have to turn off in the ECU or is this a pin that needs to be grounded out or fed 12V to make it go away?

Sounds like exhaust moisture. What header gaskets are you using?

Not completely sure on brand but they were a set that I had Kent throw in while I was stocking up on some other parts at the time.

Definitely going to check on whether they have loosened up with a few heat cycles.

And since it takes a bit to get all that exposed to get on those bolts for a tool to get on I'll probably pull the plugs to take a look and probably compression test for good measure.

That'll take a Saturday and then some.

I seem to remember the final pass torque spec on those 10mm exhaust manifold bolts being only 18ft lbs.

Whether or not I did the first pass of 11 ft lbs before going to the 18 ft lbs is one I can't remember...

I only use the original style multilayer steel shim gaskets on LS engines. Everything else leaks. I know Kent used to send fiber gaskets.

the ones i got have a shiny metal look to them as if it was composed of a stamped press of thin sheet metal so maybe they are the right ones?

decided to be motivate and wrestled my coils off so i could get at the bolts and give them an extra snug. had to just use a good extra 1/4 turn with ratchet as there was no way i was getting a torque wrench in there.

finding more issues as i dig into this. My MAF is stuck at 2.3 g/s no matter what rpm. so not sure if bad connector or if resistors in the MAF are dead or something worse. Gonna see what the response is when i disconnect the connector vs. reconnect to see if any signal change. looking up the maf connector in my wiring guide shows pin 1 as pink....... and now that i am thinking out loud..... i had this same missing rogue pink wires on my coils when i couldn't get the car to fire up. there were four pink wires all jumbled up and not labelled to which i found two of the four to be switched 12V power for the coils.... odds are probably pretty damn high one of the two other unknown pink wires was the 12V switched power for the MAF... i think i might have literally solved my problem while typing this out.... lol

will still have to see when i get another 7 day registration permit on another good heat cycle run on whether tightening the exhaust manifold on passenger side got rid of this leak or not. Also getting some burnt clutch smell so i think i set pedal too low and not getting some clutch drag. Gotta get under both sides of the dash here after my holidays i guess.

Whilst trying to tackle a slew of gremlins to get the car sorted one thing that bugged me was the fact that although i hooked up the vss and bothered to put in the pins on the ECU and the new wires for it to all be hooked up i still have idling issues with the monstrous cam in this thing.

amongst other issues in the tune i suspected how the vss was set up was probably completely wrong and i found the first obvious sign of this with the VSS pulse per revolution set to 17 when my VSS reluctor wheel from TPC is a 40 tooth.

started with the unit conversion tool within hp tuners to figure out my tire heighth and with my boxster wheels being 17's the 255/40's that are on it equated to a tire wall height of about 4" (40% of 255mm). take this 4" x two for top and bottom of tire and 17" rim and gives me the same tire height number of 25" that hp tuners shows. this is pretty much where things end for help from the software.

other reason why i thought i'd post this is that hp tuners vcm editor software has drastically changed since the captions shown in the 2009 VSS post so perhaps this more recent info will help others.

now the thing that threw me for a loop is that if you use the gear/tire wizard it actually seems to mess all the calculated numbers in the speedometer section for your vss because of the nature of our conversions using a transaxle and not a final drive gear number on an output shaft of a transmission. so skip that tool and go straight to speedometer tab/button

now the first field called VSS P. / Rev - Trans is quite easy cause you just match it to the number of teeth your reluctor wheel has. For the one that TPC sells the answer is simply 40.

the next field is called "Gear ratio & tire size". notice how this has the same name as the gear/tire wizard under the edit menu, this is where all the auto calculate issues began. Now this field is merely the transaxle revolutions per mile. Since a transaxle shaft revolution is the same as a wheel revolution in principle we can use a bit of math with the first calculation of the tire heighth to figure this out from same basic principles.
circumference =  pi X diameter so simply plug in tire heighth in inches for our diameter and we will get our wheel circumference. in my case this number is
78.53 inches. now the number for this field is looking for a unit of revolutions per mile and although you can change the unit i kept it in the format of what the field wants. so working with that we know that there are 5280 feet in a mile and multiplying that number by 12" per mile we have 63, 360 inches in a mile. divide this total number of inches in a mile by our circumference of a wheel and you get how many wheel rotations in a mile.
In my particular case this case gave me about 806.82 wheel revolutions per mile. Note that this would be the same amount of transaxle shaft rotations per mile as well since they are really one and the same as an assembly.
the caption i am posting at the end of this will be slightly off from my described example as since I'm a math guy in profession i always punch in 3.1415927 for pi and carry as many decimals as i can enter before rounding the last number at the end to something within the proper accuracy range.
next up is the final drive ratio and since our axle shafts are truly 1:1 with the wheel you just put 1 here as i borrowed from the previous knowledge of the old 2009 VSS post.
And now with the final field for VSS Pulses per mile, this is merely your total number of wheel rotations x VSS pulses per revolution of the transaxle. In my case this was merely the 806 trans revolutions / mile (or wheel rotations as explained above) x 40 pulses pre transaxle revolution. This gave me a number of 32,269.89 or something so rounded up to nearest whole number for 32,270.

now this could be something completely different if you are not using the factory ECU and using an MSD or other aftermarket controller but i'd imagine it has similar fields to interpret the pulses from the VSS sensor and what to do with it. So perhaps this helps and maybe it doesn't but at the very least it should round out the research amongst the other two super old posts that show up in advanced search.

Also if i am completely out to lunch or have done something wrong here, please let me know and i can edit correct before i do something else wrong in my adventure of "learn by doing" with this car lol.

[You must be registered and logged in to see this image.]