hesitates or stumbles on acceleration and lacks power
 

1996 Volvo 850 2.4 20v 172000km
Drivability problem - hesitates or stumbles on acceleration and lacks power
Idle - normal smooth
Rev increase normal with no load.
Temperature gauge -normal
Problem occurs seldom when engine is cold
Mostly when the engine is cold the car runs perfectly and has power
When the engine is cold it starts, but only on the second try.
When the engine at working temperature, starts normal
Problem is intermittent
Problem occurs when engine is at working temperature
Problem occurs when under load
Problem is worse when the aircon is on
Problem occurs on stop and go
Problem occurs at 900-1800 RPM
Sometimes on an uphill the engine will ping
Lacks power on a uphill
Poor fuel economy
Engine Light Always On

A2 Codes
1-1-3 (HO2S Integrator At Maximum Enrichment Limit),
2-2-1 (Adaptive HO2S Control, Engine Running Too Rich At Part Load),
Code 1-1-3 or 2-2-1 means that engine is running lean.
This may be caused by an air leak or an HO2S sensor fault.

Whats been done ->
Fuel filter replaced
Spark plugs replaced
Air filter replaced
CAT removed, replaced with box
Searched for vacuum leaks
Reset ECU

Other expensive options NOT done yet:
Replace sparkplug cables
Replace HO2S sensor
Replace MAF sensor
Replace Fuel pump
Replace Fuel regulator
Replace injectors

Please what has worked for others or what else to check.
Sending the car in next week to check the Cambelt timing

Suuggest you have an induction air leak, this link may help.

http://www.volvospeed.com/Repair/vacuum_lines.php

Also try spraying WD40 or similar around any suspect areas and see if engine note changes.

sounds like a vacuum leak to me too, when elbow at the inlet manifold if split will allow unmetered air into the inlet manifold causing the symptoms you are experiencing...it is unlikely you will be able to remove this elbow without damaging the retaining clip...
when mine went last i pulled the elbow and clip and replaced the clip with a tight cable tie..a good tip is to heat the elbow in water to let it expand...the pipe runs behind the inlet manifold so it may be easier to run a length of 4mm samco under the fuel rail....like this
http://i35.photobucket.com/albums/d1...e/4c65c5f8.jpg
or you may want to remove the inlet manifold like this...
http://i35.photobucket.com/albums/d1...Picture134.jpg
cheers
jod

no elbow
 

i have checked for this elbow,
strange thing is i do not have one.
there is not even a hole where it could have come out of.

what i did find is that at the intake the firetrap that twists in has the rubber missig that seals it. i have ordered a new one, wil fit it tonight.
i will update.

Latest Volvo advice is to remove the flame trap.

what do you mean by remove ?
just leave it open, or is there a plug to seal it?

I found other codes on A1
1-4-3 .... Short To Ground In Kickdown Switch Circuit
1-2-4 .... Short To Ground In Mode Selector Switch Circuit
2-2-3 .... Throttle Position Sensor Signal Too Low

2-2-3 would make sense to me.
sometimes when the car hesitates,i remove my foot from the accelerator, ad on just press it down, then the hessitation is gon and the car pulls.

and sometimes at about 2/3 of the way the car somtimes have power.
so maybe the sensor is faulty.

I just need to find out exactly where this sensor is an how difficult it is to replace.

i hope my problem is this simple.

Ok some good news.

I replaced the missing rubber O ring in the firetrap, and ceaned it.
I also reseted all the codes on all the pinns in socket A.

The pull-away and drivebility is better.
I only took it for a short drive and it seems beter.

I will do some traveling over the weekend, and give the ecu time to learn the new settings, since it is not sucking any more unmetered air.

I am still wondering about the TP sensor. I can get a second hand one from the scrap yard for cheap. I just want to see if the code comes back before I buy it.


my cam timing apiontment still stands for tuesday.

darn
 

That was not it!!!

still did not have power, especialy when i needed to overtake a truck
hesitates to pull away, frustrating.

I striped off the airbox and vacuum pipes, sucked and blew on every pipe.

I found that the vaccum pipe between the firetrap and the vacuum tree was completely blocked.

so I cleaned it, and removed the firetrap filter.( this was basicaly blocked too)
I also just slightly cleanded the inside of the distributer cap and roter.

hoever i ma the mistake of cleaning the MAF with a earbud, and just apllied too much pressure (I BROKE IT):angry2:

so now i have to buy one.

strange thing is on my way to work it sometimes struglle to idle (BROKEN MAF) but i sure had power, (Rainy whether- and had wheelspin in second- not bad for an automatic)

will give an update as soon as i gen my new MAF installed

Replaced the MAF
The problem persists.:hissyfit:

I decided to check the Fuel pressure and foun that it is only at 200kPa (29 PSI),
this is way lower than the specs. In the maintainance manual it stated that it shouold be at 300kPa.

There is a test procedure, jump pin 1 and 3 on the fuel pump relay(103) and see if the presure increase, if not pinch the return hose and see if the pressure rises( carefull not to let it rise above 600kPa.
if it does not rise the fuel pump is faulty.

mine dit not rise, stoot solid at 200kPa.

Over the weekend have found the problem - hopefully the last.:biggrin2:

I removed the fuel pump, just to have a look- to see if the filtes is blocked.
and there was the problem -not the filter. but the ruber hose from the pump to the metal tube was very lose.

I am sure that is why i was loosing presure, i pushed the rubber on and tightned the clamp.

Now there is no more stuttering or hesitation :Dancing_chief: