T5-r missing under load

warmblood58 · Post by **warmblood58** » 13 Mar 2016, 21:53

Took my new to me '95 T5-r on a longish drive today, all well but under a load at higher speeds, I get misses, boost gauge seems to hold steady when this is happening. At lower speeds, car is fine, in fact cruising up to 70 seems fairly smooth but when I put my foot into it, I get bucking and hesitations. This car sat for six months, fuel system flushed and treated, new plugs, cap and rotor cleaned, new fuel pump, plug wires are new per PO. Oil changed, brake system flushed. I did replace most vac lines and should have this correctly connected. I will pull cap and rotor to check for carbon tracking, pull plugs,etc. to see if they are sooted up. Tailpipe looked greyish vs black so I believe combustion is good. Any thoughts? Thanks!

Post by **tryingbe** » 14 Mar 2016, 00:06

What plugs were used?

warmblood58 · Post by **warmblood58** » 14 Mar 2016, 09:43

I used autolite coppers as they were the only copper plug that my nearby parts store had -gaped to .028. There were iradium plugs in car which I still had but PO used to start car up and let it run a few minutes and turn engine off -they were pretty sooted up - worth a clean?

Post by **abscate** » 14 Mar 2016, 13:25

Wonky ignition is the first path to follow. These cars like Bougicord brand wires, sneers from coil on plug folks aside. Coils can even fail in a mode where they run well at low load and then fritz out at high load.

warmblood58 · Post by **warmblood58** » 15 Mar 2016, 10:07

Thanks! I have another coil to swap out and will check result. Wires are new according to PO but car sat for some time, need to check to see if they are bougicard. I pulled codes 514, 521, 414, 231, and 212. My plan is to check fan relay, clean 02 contacts (hopefully get lucky here) double check all vac connections, pull cap and rotor and double check for any carbon tracking (this cap and rotor were cleaned up by me, awaiting new cap and rotor) access vac elbow below PS pump as I had not checked that connection and apparently it is a known weak vac spot. I think I will pull new plugs and visually inspect after a week of driving, might reduce gap to .026 from .028.

warmblood58 · Post by **warmblood58** » 15 Mar 2016, 10:56

time to make pressure test tool . .

Post by **matthew1** » 15 Mar 2016, 11:59

I'd go down the Volvo Stage 0 checklist. I'd start with the classic: vacuum lines and elbows. Sounds like you're on to this. Also TCV.

Ignition also good advice, fuel too.

But high load problems scream vac lines and TCV to me.

warmblood58 · Post by **warmblood58** » 15 Mar 2016, 13:15

Thanks! Found this diagram yesterday and will reference it often today as I trace vacuum circuit -some hoses were just replaced as the old hoses had this weird soft crumbly texture that would really stain fingers -totally broken down rubber. I will pull turbo inlet as well today to see what I see in around TCV. Looks like I need to pull upper rad hose and power steering line to access the infamous elbow by PS pump - hope that will work anyway -

Post by **sleddriver** » 15 Mar 2016, 21:04

You listed several DTC's, but I don't know what those numbers mean. Since the car is new-to-you, verify that the timing marks all line up. I once had a TB replaced where it was one-tooth-off. Under load, it had little power, wouldn't pull strongly under full throttle and MPG was down. Never set a code. Stumped me for a long time. Never thought to even question my mechanics work. But there it was...one tooth off.

With the engine hot, the hood open and in a dark garage, mist water over the plug wires, coil and distributer cap with the engine running at idle. Look for faint, blue sparks around all of these components. I recommend only OEM/Bougicord plug wires. High load will definitely stress the ignition system. Even more so with boost.

warmblood58 · Post by **warmblood58** » 15 Mar 2016, 21:41

Thanks, I have success! Car finally running the way it should. Wires are bougicard and do appear new. I think a little misting is a good idea but have a new cap and rotor coming. PCV system appears clean, no blow by! I found one loose hose and inlet pipe seemed loose as well. No Cel yet but I will take it on a 100 mile cruise tomorrow. Strangely, service light remains on in spite of resetting properly . . . . still cannot figure this one out!