Yummybud924

Two problems I've noticed for a while. when the engine is reved the revs fall down slowly not as fast as it should.

Also when I come to a stop at a read light a lot of time the revs will drop down to 1500-2500 rpm and stay there instead of coming down to the normal idle speed.

when I start the car it doesn't idle that high, it will idle at around 1000-1100 rpm which is still a bit high but accpetable for me lol.

now another thing I noticed, when the car is idling at say 2000 rpm at a red light I can lower the rpm by letting out the clutch to get the car to move a bit and that will bring down the rpm and get it to idle lower like 1200 rpm instead of 2000.

also sometimes after a hard drive like reving ti to 5000 rpm on teh freeway for a while when I come to a stop it idles normally but sometimes the revs stay high.

I've tried to explain all this as best as I can so maybe someone can tell me the most likely cause of this.

I'm probably using way more gas than i should by idling so high all the time.

I spend like 60 bucks on gas a week just to get to school and work.

Yummybud924

also don't want to make another thread, so I'll post it here.

I have changed my trans oil to swepco from paragon and I'm pretty sure I filled it high enough, I couldn't see in the hole but when I put my finger in there, I'd get the blue fluid on my finger. Anyways I've been running with the swepco for 2 months and it shifts great when warmed up but right now as the temps are getting lower on cold start up it's so hard to push it into first gear and when shifting into second gear there is grinding for the first 10 minutes or so of driving until it warms up then after that no more grinding when shifting into second.....

should I switch to redline maybe and see if it drives better during cold start? I thougth the swepco was the best, it was pretty expensive stuff and is synthetic like the redline. the old fluid that came out was all brown, probably never changed.

Wallace

I know for fact that redline really helped my cold car grinding.
Before, even in warmer months, the tranny would grind a little in 1st and 2nd when the car was cold.
Now with Redline MT-90, no more grinds.

I can't compare this to Swepco as I have never tried it.

Yummybud924

the swepco was more expensive than the redline and I heard it was the best so I tried that. I didn't really notice much difference from the old brown crap that came out.

when warmed up the car shifts smoothly and easily into all gears but in the morning especially now that the temps get down to 2 degrees in the morning it will grind going into second until it warms up then grinding goes away.

I guess I'll try Redline next, thanks.

is there any place in vancouver that sells redline mt-90 or do I have to order it from paragon?

Yummybud924

lol I didn't even notice that. It's the german word for engine.

just kidding.

it won't let me edit the title...... so I guess everyone will laugh at me now.

Wallace

Lordco and Mopac sell Redline.

Lordco will most likely have to order MT-90 in for you.

Yummybud924

ok cool thanks. Don't know if that'll work better than the swepco but it's relatively cheap to change out fluid so I'll try it but not going to expect miracles.

transmission on the 944 looks pretty simple to swap out but no point in installing an unknown used transmission that also probably grinds. I think 944 online sells rebuilt transmission but I don't think it's worth it to pay that much when ther is only some only when the fluid is still cold.

bearone

throttle or cruise control cable could be too tight or a vacuum leak.

87951

Yummybud924

yeah spring is on, cable is not too tight, I don't have cruise control or someone removed it.

could be a vacuum leak but why would it idle normally when you start it and then idle high only after you rev it? revs just don't fall back down.

one other thing I noticed. On really wet and rainy days I noticed, the idle does not stay high and falls down. So maybe the really wet humid air is affecting it?

so maybe a vaccum leak?

getting myself confused now.

Yummybud924

could it be the tps?

N/a 944

It... could be the tps... If you grab a hold of the throttle (underhood) and turn it just like it would turn if you pushed the gas, does it click or snap RIGHT as soon as you start turning it?
Oh and fyi, I had a similar problem recently... I dont know what fixed it but I:

Currently running a bottle of fuel injector cleaner

Checked my tps

Put a shiz load of carb cleaner down into the ISV (idle stabilizer valve) to "degunk" anything in it

Made sure the ISV worked by seeing if it vibrated when the engine was off and the key was on

Reset my idle with the idle air adjustment screw right to the left of the throttle cable (7mm socket) (on a 86 non turbo), while I had a jumper cable between ports B & C (can someone confirm this for me?) on the diagnostic port to disable the ISV, AND disconnected the O2 sensor

All of these things seemed to smooth my car out. It would hold onto revs, sometimes taking upto 10 sec to go from 2k to idle(1200rpm at the time), and I had a horrible misfire at lower rpms... Hope this helps you out!

fwb42

I thing a clue might be that the idle is ok when it's raining. Sounds like it might be a ground problem.Grounds making good contact when wet. Worth a look.Check simple stuff first.
FRED

N/a 944

Problem solved?

Yummybud924

nope haven't had time yet to check it out. Will do so during my christmas break in a few weeks.

yeah the biggest clue would be that it does not idle high when driving in the rain, like today it was idling at like 2000 rpm when I come to a stop then it started raining and the idle eventually dropped to 1000 rpm and would stay there in the wet conditions.

grounds? o rvacuum leak?

if grounds which ones and where?

thanks.