Can someone explain this
 

So, past day or so I did some decent surgery on my 944. I removed the fuel rail and manifold. Rebuilt the injectors with Rennbay's kit. Painted the manifold black. Replaced AOS seals. Cleaned ICV with carb cleaner and sprayed some silicone Teflon in there. Replaced front and rear ICV hoses. Replaced AOS breather hose. Replaced oil cap o ring. So last night I put it all back together and prepared to standby for engine fire, luckily I wasn't completely retarded and no leaks at the rail or injectors!

Last night I first started it up. For like five minutes I idled and watched for leaks. There was smoke of something burning off, probably water. It went away. So I first started it up. Idling strong at 950 RPM. Then I went for a test drive. When I went back to idle it would dip down below to as low as 550 then bounce up. If sitting idling it would bounce occasionally if I revved it and let go. It would drop Low then come back up. I used jumper cables from body to engine and that didn't change anything really.

So I said oh well and went to bed. This morning it started perfectly, idles perfectly and drives stronger than it did before. ?????

Biggest difference I noted is when shifting into fifth gear at 35 MPH. Before it would bog down a little and wouldn't accelerate much below 40 MPH in fifth. Today driving it powered through at 35, I was quite surprised.

My only explanation thus far is "your car was in a bad mood last night" lol

Take it easy, there, Schumacher!

So my gremlins have relatives! Just a question, why do you shift into 5th gear at 35 mph? I'm there at about 55/60 mph. Just ask'n.

I'm apparently a grandma. I usually shift around 2k RPM. Going onto an on ramp I shift at like 45 MPH. Maybe 40 MPH once the engine is warm but when it's still cold I like to keep the RPM's low...

Oh, God no, no one drives as carefully as I do in a 28 year old car. I don't push myself as hard any more either. Mine bogs in higher gears at lower speeds.

I'm only just turning 20... Maybe I need to live up to my boy racer stigma better? For Rasta Monsta's sake. To be honest dude, I did go to 3.5k in third today to beat a light before it went yellow. Badass. ;) Ipagolf, maybe you have some tired parts?

If you read the owners manual you would know you're pretty much never supposed to operate the engine below 2000 rpm.

Guess I missed that page.

When I get up at 4:30 every morning, everything about me feels like old worn parts! I just don't push the old guy (the car). I have a lot of fun with it, but I don't want to break it.

I have to shift at over 4000 rpm - I'm just addicted to the exhaust noise when you do it.

I tell my boys, some are older than Gaw that they never need to go over the speed limit, just get to it quickly!

Yea. This goes for just about any gas engines. (Don't know about deisel).

'Loading' the engine (i.e. in gear, driving) below 2k usually does more harm to the engine than people think. It's really not good to drive an engine like that. There is no torque and the engine really struggles quite a bit.

I've never understood the people who brag about having never taken their engine above 4k - that's not good. Nothing gets properly warm.

Take care!

Economy? What?

Lugging the engine under 2k where it has no torque, and therefore making it work harder than it should, probably burns more fuel than driving it above 2k where there is torque.

Take care!

The gnome and elf-powered CASIS light comes on at like 2,100? In most gears

Did you put the restrictor back in the hose from the TB to the J-boot?

Gaw, you need a heavier right shoe. The light comes on at higher revs if it thinks you want power not economy.

Another recommendation - buy a Land Rover as well, then you won't worry about the 944's economy!!!!!

What light? I'll wind mine out to 6K everyday I drive it.

I need mine to last lol!

To quote Samir in Office Space:"I too am not a *******..." ;)

My reasons for not exceeding 4,500rpm include
- not wanting to throw #2 rod.
- not needing to use all 168 bhp. ( M44/09 with Bursch headers & AutoThority chip )
- by 4,500 I'm already quickly passing the other cars in the lanes beside me.
- a desire to run this engine another 260k.
- by 4,000 I'm pretty much already exceeding most posted limits.

Not flaming; I'd love a chance to wring out a 944 to redline... just not my 944.

Cheers
Mike

I still need to watch Office Space LOL

The up shift light. It comes on around 2500ish RPM to say, "hey shift now and save gas!" and again at like 6000ish RPM to say, "WTF are you doing?!?! SHIFT YOU MORON!!!! Your engine is about to grenade!!!"

Yes you do. Make sure you watch the real version and not the censored TV version.

When you drive with a light foot and go conservatively and slower it comes on around 2,100-2,300 lol

To do any damage (from what I understand), you really need to run into oil starvation issues. And that only arises from prolonged time on the track, i.e. multiple hours where the car is above 4k RPM all the time.

Most of the LeMons entrants who run 944's run into oil starvation only after several hours. Some go the whole way.

It would probably be impossible to run into this issue on the street. Unless you drove everywhere at redline in first gear.

It doesn't come on at 2.5 and 6, what it is actually doing is changing the shiftpoint based on how you are driving. It only came on the series II NA cars. (Unsure about the 924S, 16V and 968) It's called CASIS (Computer something Shift Indicator System or something like that) and runs through the ECU. It varies your ideal shift point based on throttle position and other things. Pretty interesting, actually.

It might be something that runs like a computer for an automatic transmission, but rather than doing any shifting it just shows a light.

Take care!

So, I'm not using much throttle now am I ;)

What's all this 5th gear stuff? I've never had my 951 out of 3rd (hardly). I shift into 4th at 105 MPH. Only one time, I got on it in 4th - I was racing a VW GTI - and buried him as soon as I hit 100. By the time I was at 115 MPH, he'd dropped way back, so I got off it. I've never had the balls to go all the way to 5th.

I have to admit I was surprised, because at 115 MPH, at about 3,000 RPM in 4th, the car was pulling like all get out and subjectively, it didn't feel any different than say 60 MPH. I was really impressed.

My NA, I love to play with, too. There's a tight, 180º turn at work, and I love sliding around it at about 30 MPH, tached out to about 6,500 RPM in first ( I come into the corner at about 40-50 MPH in 2nd and downshift as I start the turn).

These cars are made to be driven. If I break something, I'll fix it.

What fun is it driving a Porsche, if you treat it like a Studebaker?

Jeeze!

I'm not at that engine pulling level yet, lol I'm just trying to rebuild my injectors and not have them leak.

I also like how not a soul answered my question but this became a flame thread on shift points lol.....

the simple answer is: crap in your injectors.

this is not a job to be done at home. even at the pro shops, sometimes it takes cleaning them twice. i just had to do that with a set. i sent them to one place (not my usual one) and they did not get fully cleaned, so the flow rate was off. they went out to my usual service place, and now they are perfect again.

What he said! I have mine to redline frequently, hell, the turbo isnt fully spooled until just under 4k!

I do cruise in 5th on the freeway at 80-82ish (speed limit 75) just to save gas if I drive it to work.

But sheesh,I flog that thing. Every onramp is a full blast like out of corner 5 at Road America! I heel toe and drive it like it was meant to be.

Really, why have one of these if you dont use ot like it was built to be used? Yes, IT WAS BUILT FOR THAT! These cars will amaze you at the limits of their potential, have fun with it!

Safely, of course, but you get the idea.

Jeff

Sorry LOL. It was necessary, though...:)

Toast, my '88 924S had CASIS.

Jeff

You mention that it ran fine the second time you started it up. And that you used some carb cleaner and silicone spray. Possible that some residual chemicals needed to be burned off. Drive it more and see if the behavior continues.

Maybe I'm reading this wrong, but 115 at 3k in 4th? And what gear do you cruise on the interstate in?

Interesting. It's always come on at those exact RPMs for me, no matter how I'm driving.

I believe that's right. About 3k at 115. The car was just coming into the power band.

Sure I do use 5th on the freeway, cruising along at 70. But that's about it. If I'm driving local, it hardly ever gets out of 4th.

I think they got rid of it for the S2, mine doesn't have it.

It should be at least 5k for a stock tranny, has yours been modified?

Hate to rain on the parade but I think my injector #1 is FUBAR? I re sealed and after a couple re seats it stopped leaking. Now it's leaking again and maybe worse. From the hole where it goes into the manifold. I used pure silicone to lube the o rings and nothing looks torn. No leaks from the rail or other injectors. I'm starting to think from what I've read that it's leaking at that joint where the tip meets the body? Amazed my car isn't on fire yet and I'm gonna pass out from all this gasoline. Idk what to do

Nope. You'll get MUCH better economy at low RPM with open throttle than you will from higher RPM and less throttle. Ideally, for maximum economy you'd want to be in the highest gear possible without lugging the engine.

As far as a blanket "never under 2,000 RPM" rule, that's just not a thing. The RPM at which an engine is lugging varies based on load, amount of throttle applied, and the gear you're in. Running at 1,000 RPM in 2nd gear is fine. Running at 1,000 RPM in 5th is definitely not.

That said, I certainly wouldn't be shifting into 5th at 35 mph with my 951 (45 is my lower limit for 5th gear, and that's only on level ground when I'm not going to be accelerating), but I believe that the 951 has taller ratios than the NA cars so the comparison might not be terribly accurate.

My 951.