2000 v70r mystery misfire/hesitation

brickhead · Post by **brickhead** » 31 Jan 2014, 14:21

Good afternoon all.

So my '00 v70r has misfire/hesitation that happens at low rpms and is really noticable at wot. I did have a misfire in cylinder #3. replaced that coil and reset obd. Hesitaion is still there. Scanned my vehicle again and had a fault for rear oxygen sensor. Reset obd and checked, no fault for rear oxygen sensor.
I checked turbo boost solenoid which appears to be working properly. Checked and clean air mass sensor. Checked vacuum hoses whch are in ok condition but not the best. No split vacuum hoses.

Fyi: my vehicle has stage 1 IPD tune, IPD turbo boost solenoid and IPD upgraded ignition coils. I swapped to OEM boost solenoid to see if the IPD version had failed but same symptons.I then reinstall ipd boost solenoid. Now at one time in the past I did have the flashing check engine light. I scanned my vehilce then and had random misfire. I reset and all was good. Throttle assembly has yellow tag which believe has been replaced once before I purchased the vehicle. I trying to not start throwing parts at my car in hopes to repair poor running condition.
Any idea on what else i can troubleshoot check?

Thank you. B

Bluevanacd2005 · Post by **Bluevanacd2005** » 15 Feb 2017, 09:31

Any update on this? I have the same car and the same issue. It appears to have popped up after an IPD tune. (Not pointing fingers, just an observation ). I assume since it is being pushed harder, now it has revealed some weak link.

Spenser

V70IIT5 · Post by **V70IIT5** » 15 Feb 2017, 10:55

This might sound daft but I was having similar problems on my recently acquired V70 P2 T5, today when it did its trick it also stalled on stopping. It had blown off the output pipe from the intercooler, I hadn't tightened it enough. It has made me think the problem is boost air escaping on hard acceleration. Could this be your problem too?

Bluevanacd2005 · Post by **Bluevanacd2005** » 15 Feb 2017, 12:21

I will check my hoses. It's pretty random though. If I disconnect the battery for a while, it goes away for a bit.

Post by **rspi** » 15 Feb 2017, 14:47

If you have a misfire or lack of power it's best to follow the codes. Also, need good plugs, coils, etc.

Bluevanacd2005 · Post by **Bluevanacd2005** » 15 Feb 2017, 19:21

There are no codes (CEL does work). I replaced the coils and plugs. Compression check showed 150 psi on all cylinders. I replaced the fuel filter and air filter. Replaced the knock sensors. Ran a couple cans of sea foam through it. Fuel pressure is 65 psi, reving it or loading the engine doesn't change it much. Cleaned the MAF with the special cleaner. No crank case pressure, it passes the glove test.

Not sure what to do with it now. I checked the voltage on the battery, it's good. Cleaned the terminals anyway.

I figured I'd just replace all the sensors and see what happens. Maybe I'll find something else in the process.

I ordered a crank sensor, cam sensor, MAP, air temp sensor, and MAF. I also got a brand new set of Bosch injectors to rule that out.

Thanks for the help,

Spenser

Post by **abscate** » 16 Feb 2017, 04:30

Coils and connectors need to be tight, check both coil and injectors for 12 volt supply. Both of these fire by grounding at the ECU, so wiring harnesses need checking.

Bluevanacd2005 · Post by **Bluevanacd2005** » 16 Feb 2017, 09:11

Thanks for the tip, I'll check it out too. It normally doesn't misfire, but once in a great while at idle I'll get one random misfire. Then at load and high rpm it's repetitive on random cylinders.

Bluevanacd2005 · Post by **Bluevanacd2005** » 03 Mar 2017, 17:58

Alrighty, here's an update:

I replaced:
-MAF
-MAP
-Inlet air temp sensor
-Injectors
-Hoses to waste gate solenoid
-Went back through the coils and wiring, cleaned them up and put new plastic corrugated sheathing over them

Not much change in performance though. The injectors may have helped a little. But the misfire is still happening. I looked for wires that were in trouble, but didn't see anything out of the ordinary. Both engine-to-body grounds are intact. Still no codes. I also checked the induction piping, and didn't see anything loose or broken.

Something else is happening too though. When taking off, if you put it to the floor, it stops accelerating when shifting from 2nd to 3rd (around 50mph) for several seconds. Just like it dies for a second. Really wierd. Doesn't happen as much/as bad when at 90% throttle instead though. I checked the trans fluid and it looks normal and is at the correct level.

Any insight? I'm wondering if these issues are related at all. The car is plenty drivable, it just isn't 100% right.

The next two sensors I have on the list to replace are the cam and crank sensors. Just didn't have enough time today. I also have a compressor bypass valve diaphragm I need to put in, but it looks like a pain to do without removing the turbo, so I have been avoiding that job. I could replace the waste gate solenoid too, it doesn't look that great, maybe it's tired and leaky.

Thanks for the help,

Spenser

Post by **scot850** » 03 Mar 2017, 23:08

Sorry to hear of the hassles Spencer. My 2000 'R" PITA has also decided to join the club with a misfire. No CEL, and does not seem to affect it in normal running so far, and only seems to happen noticeably at idle. Tried moving trans to N but no difference. I had put this down to the car being upset as it has been ejected from the garage while I work on the V70 NA project. I also stopped using it for a while when the rear washer stopped working again during a prolonged cold spell and I couldn't get it into the garage.

I don't drive much anymore so it can just sit and sulk until I can get the project back on it's wheels so I can get it into the garage and try to see if Vida finds any codes.

If I find anything I'll let you know. Hope it is not the head gasket after the overheating issue when the radiator top hose blew!

Good Luck,

Neil.