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loose boost on low RPM's

 
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Ari  



Joined: 25 Jun 2003
Posts: 31
Location: Finland

PostPosted: Tue Mar 09, 2004 7:32 am    Post subject: loose boost on low RPM's Reply with quote

Few days it has been like that. When I start accelerating 1st gear the engine is really ineffective until it reaches something like 2700-3000rpm and then it starts kicking some butt. Any suggestions what should I check first?
I noticed that my fuel consumption has lowered quite much still I've been quite heavy footed thought. can't say if that has anything to do with the loose boost..
Oh about the ineffectiviness I say that yesterday I drove like normally I do and then there came this quite steep uphill. ok, i had 2nd. gear on and there were something like 2200rpm's in the machine and i pushed the gas pedal alltheway to the ground but the tires didn't even start loose traction until they reached ~3000rpm's... And we have winter here... that does say quite much I think.. I apology again my lousy english.

-Ari-
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-87 924s euro
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Lizard  



Joined: 03 Nov 2002
Posts: 9364
Location: Abbotsford BC. Canada

PostPosted: Tue Mar 09, 2004 8:35 am    Post subject: Reply with quote

when was the last tune up performed?
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Ari  



Joined: 25 Jun 2003
Posts: 31
Location: Finland

PostPosted: Tue Mar 09, 2004 8:46 am    Post subject: Reply with quote

Can't say 'bout that. I haven't got that car so long. There was made normal maintenance but I don't know nothing 'bout tuning it up. What it contains especially? I have to take that car to the carage anyway and I would be pleased if you give me some advice here.
-Ari-
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Ari  



Joined: 25 Jun 2003
Posts: 31
Location: Finland

PostPosted: Tue Mar 09, 2004 8:55 am    Post subject: Reply with quote

But i'll say that the car was un-used something like 1½ years before I got it. Ex owner just started it sometimes. that's all. Idle is quite bad. Rpm's wanders all the time an it causes my steeringwheel shaking like possessed. only when the engine is cold the idle is good 'cos it keeps above 1000rpm's then... Sparkplug cables are quite bad looking also. I think one of them make sometimes bad spark.
-Ari-
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Lizard  



Joined: 03 Nov 2002
Posts: 9364
Location: Abbotsford BC. Canada

PostPosted: Tue Mar 09, 2004 9:19 am    Post subject: Reply with quote

ok first things to do is,

replace the spark plugs, wires, cap and rotor, also replace the fuel filter, and drain the gas tank and remove primary intank pump and verify that it is not gummed up, and then you should also consider intalling a pressure guage on the fuel rail to verify that you have the correct pressure there,

if you have poor driving that is not caused by engine hesitation, repack/replace wheel bearings, inspect all tie rods (inner and outer) and also check the steering rack for "play", also look at the strut tower hats, they should not have a gap between the top hat and the plate that bolts to the frame. also inspect all bushings
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gohim  



Joined: 02 Nov 2002
Posts: 4459
Location: Rialto, CA

PostPosted: Wed Mar 10, 2004 5:41 am    Post subject: Reply with quote

You need to have the "Front of Engine Service" performed on the engine immediately. Do not drive the car anymore until this critical care service is performed.

Without having this service performed every 30K or 3 years, there is a high probability that the water pump may seize, a roller or pulley may seize, and oil leak may dump engine oil onto the belts and weaken them, the belts could become loose and jump a tooth, the belts will also wear, become deteriorated, and may loose teeth, allowing the timing to jump. All of these conditions/actions will result is severe damage to the valves, and possibly the engine block.

The "Front of Engine Service" includes the replacement of the balance shaft and timing belts, bearing equipped belt rollers and pulleys, water pump, and the front of engine oil seals. Since you just bought the car, I recommend that you have the oil cooler seals replaced at this time, as long as the car is at the mechanics (engine oil and coolant "mixing" due to failed oil cooler seals is a common problem on 944/924S engines).

While the car is at the mechanic's you should replace the spark plugs, distributor cap, and distributor rotor, engine oil, coolant, and flush the power steering system. Inspect the spark plugs wires for cracks or other deterioration, and replace if necessary (whole set).

This will probably cure the performance problem that you noticed. However, the 944/924S engine has a rated 150hp (US 1987) or 160hp (US 1988). It has a nearly flat torque curve from about 1600 to 4000 rpm. The 924 turbo is rated the same total hp, but the torque curve is very steep with little power below 3000rpm. The numbers that I quoted here are not exact but for comparison. So 924S/944 engine performance is not the same as a turbo car with pulling pwoer from down low, and no big bump at high rpms. The Turbo cars are weak down low, and explode at high rpm. So the seat of the pants driving performance is completely different.
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Ari  



Joined: 25 Jun 2003
Posts: 31
Location: Finland

PostPosted: Wed Mar 10, 2004 7:45 am    Post subject: Reply with quote

ok.
Spark plugs, oils (ofcourse),
inner and outer tie rod (for the drivers side),
bushings for the drivers side,
belts for distributor (and tensioners *2) and balance axle belt,
gasket for "middle deck" (don't know real name for it but it's under the valve housing/case and it leaked oil like he*l)

Those parts were changed in the maintenance as i remember. Didn't really know that waterpump has to be changed so often in this car so that wasn't changed..

No I mean that my steering is fabulous. There's no play at all after the tie rod and the bushings for the drivers side was changed. Passengers side is ok.
Only thing that matters with steering that sometimes the wheel is pulling for the left. It feels like a spring is forcing. Sometimes I can hear that sound coming like spring turns. BUT! If i take everything to the right before i go, it won't force the wheel. not until I take it to the left (plenty)and then again...??

I mean that the idle is so bad that the whole car just shakes. I've checked motor mounts but they were ok. Idle causes the shaking wheel also. There is no power steering in my -87 924s euro car. Don't know if there ever had been.

And one stupid question for the end so you guys can get a good laught at me... When i said that the tensioners were changed for the distributor... they were but why the belt has to be tensioned manually if there's tensioners? Shouldn't it be the proper work for 'em?

p.s. I've heard that there is something called tps (small black box) under the intakemanifold that should be cleaned up sometimes?
Thank you for your advices,
-Ari-
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Paul  



Joined: 02 Nov 2002
Posts: 9491
Location: Southeast Wisconsin

PostPosted: Wed Mar 10, 2004 10:36 am    Post subject: Reply with quote

As the factory manual states, check the engine grounds before doing any other trouble shooting on the DME system.

The ones under the heater valve on the back of the engine were completely corroded on one of my 924S cars (heater valve was leaking on it). This caused all kinds of havoc.

One of my other 924S cars had a bad gasket on one of the intake runners. This caused a very rough idle and a lack of power at low rpms.
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Ari  



Joined: 25 Jun 2003
Posts: 31
Location: Finland

PostPosted: Thu Mar 11, 2004 7:54 am    Post subject: Reply with quote

Got to check those too.. hmmm... my exhaust manifold seems to leak some gas. I noticed it after i shutted the engine and lifted the bonnet. Not much but little. It can't cause that? I think that the intake side is ok. I bet that there is lambda sensor in this car?
I don't have a clue about anything what this car contains. I must buy some books I think .
I'll check those things out in few days and come back to the bisness . But if you folks have something in your mind. just let me know!

HEY!!! Can this thing make this lackness of power??! I've installed a block heater to this car and now i've noticed that it leaks cooling fluids.Not much but still leaking. I'm gonna find that leak but i think I know that it will be found there. Not quite nice place to climb and see.. Thank you!!!
-Ari-
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wdb  



Joined: 02 Nov 2002
Posts: 2024

PostPosted: Thu Mar 11, 2004 12:29 pm    Post subject: Reply with quote

if your idle speed is not steady , you have a vacuum leak ,tighten all the clamps on the intake and check or replace all the small hoses on the intake system .
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