98 v70 with occasional loss of power and bucking

[Volvo_240_Atari_2600]

Bellow is a description of what I ran in another post:

I went through the changing of plugs and dist cap and rotor w/ throttle body cleaning, maf cleaning etc... I did not change the BOUGI cords that I installed in October 2007. (Dist cap and Rotor were also aftermarket that I got from FCP)

The plugs I initially used were Bosch Platinums (WRONG)
The car did not take those very well and it coughed and choked until I replaced them with VOLVO 4 prong oem's from FCP. That was a few days later. All went back to normal until about a month or so ago. The car started to stall, and choke/buck sometimes while coming to a stop light and buck at acceleration when the light turn green.

Two weeks ago I took the car for a few days and ran the codes.... I have had P0445 for a year now (the one that indicates fuel or fuel/vacum loss?) Haven't gotten around to looking into the vacum lines as yet.
I was surprised to see P0302-303 and 304 along with I think it was P0171 (not sure if the number is right) but its the one for the MAF sensor.

Remedy:
seafoam
Maf and maf contact cleaning. (yes, I did use the correct cleaners)
cleared the codes.

So far... first few days no dramatic changes... Car did hesitate on me twice. (P0445 was the only code to return about 3 weeks ago)

Towards the end of my few days of usage, I eliminated the hose, mind you I did the mod keeping the cold air intake open since August. I sis also seal the opening for the hot air side once the hose was removed.

Lets just say that the P0445 code would normally return after about two days from being cleared, maybe three.

Today, over a week later the car does not hesitate, stall or buck... As if there were no problems ever. Neither one of those codes ever returned and the car seems to run fine.

I read some threads here on the codes and remedies I mentioned above.
I did order new OEM plugs again, as a just in case and a new BOSCH cap and rotor as well as a new set of BOUGI cords from FCP... should arrive today.

Today after more than two weeks with new cap/rotor/wire and plugs, the car still is acting up.

What happens is the car does still have a loss of power at continuous acceleration. (this is not an all the time thing) but this is becoming anoying, not to mention my wife feels vulnerable with the car like this.

Sometimes, we stop at a light, and you can see the RPM twitching and the car starts to buck and stutter like it wants to die.

Any idea as to what else I should look into to have it run smoothly again?

Note that since I replaced the wires, cap rotor, plugs MAF cleaning and Seafoam through the intake, the car acts up from time to time but not a single code pops up now.... Lets say its been a good three weeks since I started all these maintence items and no codes.

Thanks
Eric

[jblackburn]

Unplug the MAF entirely and take it for a drive, or keep it that way for a day or two. You won't do any damage, there will just be a lack of power from what you're used to, and you'll use a lot of gas.

As far as the pesky P0445 code...there is a vacuum elbow under the battery tray that cracks, and also (probably your problem) the one leading into the charcoal canister under the rear wheel well after the gas tank. I bet that's your problem with the EVAP leak. A vacuum leak could cause bucking/stalling issues, but they would be more than just intermittent...that still sounds like a bad MAF sensor to me (which rarely throws a code).

Here's a lot more information about the evap system:
http://www.bba-reman.com/content.aspx?c ... _DTC_P0445

If running the car without the MAF doesn't solve your problem, you may have an intermittent signal OR a bad ground connection from the CPS sensor causing the intermittent misfire codes. Sometimes they will throw a code for these, sometimes they wont.

[dongafish]

I had a similar intermittent issue after a spark plug change. Apparently, I loosened the ground wire when I was removing the coil packs. Check your connections.

[Volvo_240_Atari_2600]

jablackburn,

Thank you for the reply... I have my wife's car now on a temporary test drive swap and I will try unplugging the MAF sensor as you suggest and see what happens.

This weekend I will look into the P0445 issue as I do have time this weekend.

Dongafish,

Thank you for your two cents.
I noticed you have a 99 and if I am not mistaken the difference on yours to mine is that I still have the single coil and you have one coil pack for each plug. Or am I wrong? I will look at my coil when I get off of work to see if anything came loose when I changed the coil to distributor wire.

My big question as I cannot seem to find anything here on Matthew's on the COIL itself but whet I threw "bad ignition coil symptoms" on google, I got allot of information on just about every other car forum you can imagine from Lexus to VW that describe a bad coil similar to what this car is suffering.

So... has anyone here had this problem and replaced the coil?
If so...
Was it a BOSCH unit?
Or what about the loud orange one from IPDUSA.com?
I noticed Groton with a Bosch coil but it is sold separately from that little plg thing on the bottom of the bracket.

If I replace the coil, do I need to replace that little electrical conector as well?

I hate to spend money on parts that are not needed, although its always good to know that on today's date (whetever it may be) that I replaced this or that and I have "x" amount of miles or years till I need a new one.

Problem is, I just dropped a load of money on my 240 and I have all these heater related parts I recently bought for her car that I need to replace this weekend.

I need to fix this bucking and wanting to cutr out and sometimes cut out problem once and for all but I just hate spending money on items that are not the issue at hand.

Thanks
Eric

[jblackburn]

If there are any junkyards close by you, you can easily pull one off a junk car and try it out for much less then the $100 something you'd spend on a brand new one.

Look under the hood at night with the engine running and see if you notice any blue arcing from the coil.

[Volvo_240_Atari_2600]

If there are any junkyards close by you, you can easily pull one off a junk car and try it out for much less then the $100 something you'd spend on a brand new one.

I agree... one of our local self svc yards just brought in a 98 s70 na but I was a day late and a dollar short.

Someone beat me to the MAF sensor, the coil and the driver's side master window switch.

There are a few 850's that were waiting to be placed with the general population and my guess is that they may be available Monday.

By the way... I did unlplug the MAF sensor and the car ran REAL ROUGH!
I read many posts about that and the car ran, hesitated and did start up everytime I turned the key with it unplugged. That firced my CIL and SEL to come on. After my breakfast, I will check the codes to see if the MAF forced any others like the P0445 to come on as well.

I did plug it back in and so far none of the intermitant bucking and cutting off. This seems to be the mystery gremlin that loves to show up when she has the car, now mind you I have had that experience in her car as well, but it seems to happen everyday she has the car.

Look under the hood at night with the engine running and see if you notice any blue arcing from the coil.

I will look at this tonight.
Thank you
Eric

[Volvo_240_Atari_2600]

jablackburn....

I tried looking at the coil after dark, headlamps off in a pretty darkened driveway and I did not see any evidence of "blue arcing" from the coil.
While the car was running I touched the coil... Nothing
I touched/felt the rubber boot over the coil and that felt like it was vibrating... almost like it was popoing, or firing under the rubber.

Normal I guess?

i'be been up since 6AM reading the boards and I came across these recent threads about the CPS

https://www.matthewsvolvosite.com/forums ... =1&t=26279
cps and seal r&r

https://www.matthewsvolvosite.com/forums ... =1&t=26279
no spark from coil that leads to cps issues

In the later one, I believe it was you that said this:

However, if you have an intermittent no-start or running condition, this test can't help with that. The sensors tend to act up at an older age when they get hot.

Am I on the wrong path to believe that this could be my issue?
It was stated as a "no start or running condition." Rwas that running meant for poorly running?

I am stumped here.

[jblackburn]

I meant "intermittent poor running" or something of that sort. Yes, the RPM sensor will do that, and could be the root of the symptoms you're getting. The intermittent loss of power you're getting makes me suspect that over anything else...it simply sounds like a bad signal or loose connection from something to me. They are fairly cheap ($45 on FCP) compared to the ignition coil.

Someone suggested a bad ground connection...that could definitely be a cause. The ground cable is at the back of the firewall on the drivers side...make sure it's fastened down securely.

I've never had a bad ignition coil myself, so I'm not entirely sure what to look for there besides the arcing. I'd try to snag a used one if your junkyard gets those 850's through and see if matters improve. Wouldn't hurt to grab a MAF sensor too!

[Volvo_240_Atari_2600]

Thanks
I'm heading to the yard at lunch on Tuesday.
When you say RPM sensor, are you also refering to the CPS? Cam Position Sensor? Or the Crank Position Sensor?

http://www.fcpgroton.com/product-exec/p ... ory_id/111

I saw it as you said at FCP for $45 and iy looks like the one on the 240 which I know as the Crank Sensor

Two names?
if so or not... Where is this found on the 850/s-v series please?

Thanks
Eric

[jblackburn]

Sorry for the confusion...yes, crankshaft position/RPM sensor = same thing, and that is the right part you linked.

The cam position sensor is right behind the distributor on the main engine block.