98 GLT Misfires, details inside, replaced a good bit so far.

canyoudig_it · Post by **canyoudig_it** » 12 Dec 2012, 03:12

About the misfires. There is not rhyme or reason to them that I can tell, except in a few parts of town it acts the same in certain spots almost every time. Ok, so cranking the engine cold there are rarely any issues, but when there are I have to try it a couple of times for a few seconds before it starts, then it misfires during idle and for a about 1/2 mile afterwards. If it starts fine the first try, no rough idle, good start up the road. There is one place on my way to work where I cross a bridge and where it meets the road is rough, causing my cars suspension to shake a lot, I turn right shortly after that. I would say half the time I take the turn, it misfires when giving it gas.

One spot in town I park to get food real fast is facing down a hill, I park with my engine facing down. I am usually in and out in 10 minutes, and when I get back its rough to start and misfires most of the way home (about a mile).

The misfires seem to occur more during turns, then start firing correctly when I straighten up.

I recently had to drive to my dad's, 30 miles one way, mostly 50-60 mph. My car did not give me any trouble the entire day. My job is 3 miles away, I usually only reach 45 mph on my way there. That's when I have the most trouble with it.

~180K, the misfires started a couple of months ago. I have replaced the spark plugs, spark plug wires, distributor cap and rotor, and the ignition coil. All but the ignition coil really needed it, thinking about putting the old one back in because the new one makes an audible ticking noise you can hear inside the car.

So now I'm thinking it may be my fuel pump? Or relay, both? If not them, what else could it be? Still a car newb, trying to spend as little money on a mechanic as possible. Thanks for any help!

Post by **jblackburn** » 12 Dec 2012, 07:37

Try jumpering the fuel pump. Remove the upper relay cover, remove relay #103, and stick a paperclip between pins 15 and 87.

Post by **rspi** » 12 Dec 2012, 08:05

What parts did you use to do your tune up? Volvo's don't like many after market parts.

canyoudig_it · Post by **canyoudig_it** » 12 Dec 2012, 12:15

jblackburn wrote:Try jumpering the fuel pump. Remove the upper relay cover, remove relay #103, and stick a paperclip between pins 15 and 87.

What will this do? Reinforce a connection that may be loose? Thanks for the suggestion!

rspi wrote:What parts did you use to do your tune up? Volvo's don't like many after market parts.

I used NGK spark plugs, they ones I took out were NGK as well. The Spark plugs wires are Bosch, The distributor cap I bought was aftermarket form Advance Autoparts, but ended it up it had Bosch written all over it. The rotor I am not sure of, it was not labeled (also from Advance). The ignition coil is an aftermarket, very cheaply priced (~$50). I am thinking of putting the old one back in for two reasons, one is I don't think anything is wrong with the old one after having it replaced, and the new one makes an awful ticking noise.

Post by **cn90** » 12 Dec 2012, 12:31

Yeap,

Put the old ignition coil back in.

Wire, Bougicord is the way to go ($50 online).
Bosch wire, search forum.

canyoudig_it · Post by **canyoudig_it** » 12 Dec 2012, 13:06

I am not sure if it's clear or not. The misfires began happening BEFORE I replaced anything. I have been replacing piece by piece to see if the problem is resolved, with no luck so far.

Post by **jblackburn** » 12 Dec 2012, 13:07

The FP relay is a common problem with age - it makes an intermittent connection that can cause stumbling, hard starting, or leave you stranded.

Try the paper clip trick for a day or so and see if it runs fine before buying a new one. The relay serves to "prime" the pump before starting the engine, and also to cut off fuel in the event of a crash.

One other thing - unplug the mass airflow sensor and see if running smooths out at all.

A cam/crank sensor may also be causing issues, but let's rule out one thing at a time and start with the easy stuff first.

Is your computer showing any stored codes running like this?

Post by **cn90** » 12 Dec 2012, 13:22

1+,

Jump 15 and 87 as outlined here:

https://www.matthewsvolvosite.com/forums ... hp?t=52252

canyoudig_it · Post by **canyoudig_it** » 12 Dec 2012, 14:02

Just put back the old ignition coil back in since it runs ok.

I forgot to mention I also replaced the Mass Air Flow sensor. It was the first thing I replaced. When the problems began I would take my air box off and run it for a few seconds without a filter and that fixed it every time. Since replacing the MAF, I haven't tried this trick, but the misfires occur a lot less frequently than they used to. I am certain the misfires initially were due to many problems, the spark plugs and distributor cap being the main culprits. The spark plugs I couldn't measure the gap in them on my tool they were so far gone, and the cap, I have no idea how it was getting a spark to the plugs with now filthy it was inside.

I do know of one small tear in an intercooler hose, it's on the rubber tubing (connected to a metal tube that runs over the engine to the turbo) that feeds into my intercooler right next to the engine's intake (I hope I described that correctly). I does not suck in air it seems, but blows it out, I used a small piece of thin paper to determine nothing is being sucked in, but it blows a bit of air out of the hole.

Another possibility is one of my vacuum hoses to my engine has dry rotted off. Volvo would not give me a part number, but offered a replacement for ~$120. It's a very small diameter hose, three of them are connect to the side of the engine facing the grill, two on top, one on bottom, the one on bottom is the one that has disconnected. If anyone could point me in the right direction for an appropriately priced replacement I would be grateful.

I know these can cause misfires, but with how randomly they occur, I feel it's a part failing and not a loss of compression.

I haven't checked the codes in a few months, only because I have no way of reseting them. If I understand correctly, this model car, when a code is put up, it stays up until a tool Volvo has is used to reset it. The last time I had them checked, I had three codes I believe, random misfire on all cylinders, number four misfire, and the last may have been a compression problem ( due to what I mentioned earlier, also I had to replace the rubber tubbing on my idle control valve (I believe that's the part, right in front of the engine), the rubber turned to plastic and had a cracked all the way down the side. Sorry for not being very knowledgable on all the part names.

So to recap what's been replaced, plugs, wires, cap, rotor, coil, MAF, rubber tube on idle control.

What I know is wrong, small tear in intercooler hose, one of three vacuum hoses is dry rotted off.

Thank you for linking that post! I did not know I had to take off another cover, I was about to go fishing around in the trunk looking for fuses. Do I need a jumper wire with a fuse, or can I use just a paper clip like jblackburn suggests?

canyoudig_it · Post by **canyoudig_it** » 18 Dec 2012, 02:49

Bump for some clarification.

Do I need a jumper wire with a fuse, or can I use just a paper clip like jblackburn suggests?

Also I noticed today it stalling out in the parking lot at work while trying to make a hard right turn. It did not do it turning left. After straightening the wheel it went away, causing a few misfires until I got the car rolling better. Does that throw up any flags?