98 s70 NA idle: Im pissed off Topic is solved

Post by **CIK7** » 01 May 2021, 15:19

I drove it home from Fort Smith just fine with a slight idle/miss. The idle has only gotten much worse as ive been diagnosing the misfire/rough idle issue. I have searched 'p0505' within the first 5 search result pages on here. That stuff didn't help me. Please refer to pictures of code p0505 and Youtube videos of the idling. Please watch video #1 before #2.

Post by **volvolugnut** » 01 May 2021, 15:33

Rough idle is often caused by a vacuum leak. I recall you changed vacuum hoses and you may have left one off or loose. Check them ALL again.
volvolugnut

Post by **CIK7** » 01 May 2021, 15:55

volvolugnut wrote: ↑01 May 2021, 15:33 Rough idle is often caused by a vacuum leak. I recall you changed vacuum hoses and you may have left one off or loose. Check them ALL again.
volvolugnut

There is supposed to be a line going to airbox but there is none because previous idiot replaced it with cai w/o doing his research. He capped it off. Also my intake hose to the TB is almost completely torn and worn off. Idiot chose to use glue in order to keep it together. Its not together though. This dude chose not to replace any item needing to be replaced but thought blowing $900 on wheels and another $100 on CAI was a crafty idea. What a joke! Ive spent the last week NOT driving my car in order to replace all the parts he did not. My mom, not knowing anything about cars, called my GT a pile of junk. Both mom and dad think Volvo is trash because of my luck with Volvos. Id like my dad to trash his 2019 Ram before he talks about my car choice.

Post by **CIK7** » 02 May 2021, 16:06

Don't ever buy this replacement part on eBay. The pcv notches were wrong and the pcv connection was superglue on there. Im pissed off. My anxiety was hyped and after breaking this new part, it went back to being hyped again. The Chinese cant make crap right. And Im an idiot for cheaping out for that crap.

Post by **CIK7** » 07 May 2021, 20:52

Has anyone watched my linked videos? Opinions?

Post by **scot850** » 08 May 2021, 00:30

I have watched the videos, but neither link seems to work.

The unusual idle is hard to diagnose as there are so many things to check.

What I did think odd was the extremely rough start in the 2nd video. That is definitely not normal. Seeing how much the car jumped something is out of whack for sure.

Being a 98 and an NA should make it a little easier (relatively)!

The usual suspects are:

Electrical, gas and ignition.

Electrical:

All basic checks:

1) Grounds and earths. Check the condition and look for corrosion in the battery wires and the leads to the starter and alternator. Finally check the B+ cable from the battery to the main fuse box. Pay attention to the connection in the main fuse box looking for matte finish to the nut and wire end showing signs if internal shorting and overheating. Battery we will leave for now as it seems healthy on start.
2) When were the plugs last checked and gapped? Check the ends of the plugs for color and condition

Gas system. This includes fuel pressure and filter. Also check injector leads and if any oil has leaked into the plus. Code P0505 is for an IAC fault. Check out this link:

https://volvoforums.com/forum/volvo-850 ... ery-70626/

Ignition

1) Check rotor condition and distributor cap for condition and cracks. Check the distributor for oil leaks from the cam seal
2) How are the cam and crank position sensors. If either are failing they will cause the rough running
3) Ignition/spark plug wires
4) If you start the engine and it runs rough, if you switch off an then restart it is there any change? This would point to the ignition switch failing

There are many more possibilities, but those include checking all the pipes in the engine bay as suggested earlier and timing belt and the timing marks.

Got to start the the obvious basics.

Good luck, we have not forgotten you!! Sorry for the late response have been building a new fence for the yard under duress from the 'boss'.

Neil.

Post by **Chuck W** » 08 May 2021, 06:33

Have you checked the coolant temp sensor and connector?

It looks like it's fairly warm there in the vid, but a bad read could be causing some problems.

Post by **CIK7** » 08 May 2021, 21:03

Im so EXCITED! I finally get to DRIVE MY CAR. I found the culprit. Yes Neil, new plugs (gapped) and wires 2 days ago. Tonight I installed the last vacuum line, the fresh air hose, and it STILL ran rough. So I went around the engine bay scratching my head. I saw something strange with the placement of 2 plug wires when I was trying to figure out which way it goes from Cyl 1 to 5. I looked up Robert's video about the order of the cylinders. And I figured out I accidentally had installed the plug wires for cylinders 1 & 2 wrong. Once I swapped 1 to 2 and 2 to 1, it ran great. Problem solved!

Post by **ZionXIX** » 09 May 2021, 06:17

Sometimes it's just that simple. Glad you fixed it. Rub that in your Dads face

Post by **scot850** » 09 May 2021, 08:47

Well done that man! I have to admit to having done that before. Not on a Volvo but 1955 Morris Minor we had. Actually not sure we were responsible for that one. Car ran rough and had even less power than I expected from an 800cc side valve motor. Decoded to checks and went through the list and got to the plug wires. Started to run engine and pulled each lead in turn. First lead, engine really stumbled, 2nd lead the same. 3rd and 4th lead no change. Checked firing order and found they had been reversed! What amazed me was it meant when testing it had been able to run on 1 cylinder! Car was considerably more perky after that!

Also managed to trap and damage a P80 lead on a 98 XC. Caused a misfire and short.

All in all, impressed you kept your head and worked it out!

Neil.