MrShim78

Hi Guys

Ok so this is one I cant find anything int he forums for. need your help and advice...
Here is what started happening about 2 weeks ago

1. when going slow and turning left (or right but its more on a left), like at a light or from the parking lot, the car hesitates , well rather, does not keep a constant increasing rpm., it struggles to push the rpm up.

2. so as i accelerate and turn , i feel the car struggling to push up the rpm. this happens for about 5- seconds then the gear shifts and its ok again, or the rpm does pass say 2.5k or so and its fine.

3. i dont think its the tranny as in a straight line there are -no- issues with acceleration its fast and smooth as always. only when turning.

4. pcv was changed 10 months ago, oil change, air filter, all is done already. i will chaneg the pcv anyway to see if it goes away. besides that.... what else could it be??
my suspension has strut mount noise, sway bar links were changed 6 months ago. besides that no other issues with it. power steering fluid was changed 8 months ago and is cherry red still.


any thoughts guys? Eengineer? MrBooby?

Hayk

iTrader: (1)

Whenever you use your power steering pump, there is too much stress on the engine, for whatever reason. Even though your fluid is good, there could still be an issue with the steering system.

I would start by turning the wheel in park, and listening for any abnormalities. I would then remove the power steering pump belt and try the same thing again. This will isolate the pump.

MrShim78

thanks i will try that ....
do you think changing out teh fluid will help? i changed it out 10 month or so ago. as well as adding some lucas power steering stop leak...wont hurt i guess?

MrShim78

HI all,
thanks MrBooby for the tips...i did a bit more testing...

so apparently its not only when i turn. its gotten a bit worse, and the hesitation happens only when the car starts from zero, ie a red light, and only happens initially. when i give it a bit more acceleration/power the issue goes away , and there is no hesitation beyond 2000 rpm.
if it was related to the engine, and i know it could be alot of things, but what could i start looking at first?

Hayk

iTrader: (1)

I would try cleaning out the IACV, MAF sensor, Throttle Body Plate, and replacing the PCV Valve.

EEngineer

i'm 90% sure there is something wrong with your PS idle-up system.
just behind the intake manifold, there's a little cylinder that have 2 vacuum lines coming out of it.
one goes to intake manifold, and the other goes to IAC IIRC.

the lines are rather skinny and may have gotten clogged or pinched closed.

when your ECU detects load at your PS pump, it will squirt extra fuel and open the PS idle-up lines. With the extra fuel and air, your idle goes up to drive the PS pump....in your case, somehow the air is not getting there, that's why your engine rpm won't go up. but with the extra fuel, it'll run super rich for an instant and the engine will feel very boggy at that moment. this is consistent with the fact that when you let the TB open, everything is fine again.

another case is that your PS pump bearing starting to seize. let's just hope this is not the case. your motor still have enough power to make it spin, but the extra friction make the load high and make the normal idle up insufficient. small chance, cuz it'll probably make a lot of noise.

MrShim78

thank you both MrBooby and EEngineer for your input. i will look at both items over this weekend. the car needs an oil change too so I guess i'll start there and then after go into the pcv valve and all those other fun things

also, EEngineer, i dont think its the bearing cause there is no loud noise, nothing atleast that is out of the ordinary, i listen to my car alot (with the radio off and windows open lol) so the noises are all 'normal' so far...

i'll keep you guys updated, thanks again for your input.

LeX2K

The ECU does not detect any load on the PS pump directly, the idle up valve responds to hydraulic pressure. When you turn the wheel, the pressure goes up and the valve opens, allowing air to bypass the throttle plate. Because there is more air, the ECU responds automatically by sending more fuel to the injectors.

If the idle up system is not working, the idle will simply drop when more load is put on the PS pump, the engine will not enter a too rich fuel condition. Here is the diagram of the idle-up, there is no electronic connection to the ECU at all, it is about as simple as it gets, a valve and two vacuum lines.

MrShim78

Hi everyone just thought i'd update this thread.

thanks to everyone for pitching in
here is what id id, most likely air filter change (go figure) fixed it but not sure.

1. pcv valve replaced
2. new air filter
3. new egr position sensor (threw a code, had another thread on that).
4. new PS fluid with some lucas mixed in for some help. not sure if it helped.
5. throttle body cleaned out.



hesitation gone!
have not done maf sensor yet and an debating if i should or not. its an expensive thing to mess up but i am sure that since the car inception in 1997 it has not been cleaned, ever. what do you think