'98 V70 T5 won't start, P0301 & P0304

[800artfreed]

Any resolution to your problem? Really curious. Thanks

[hipcheck]

Sorry if my rambling was not clear. I did a major tune up when doing the PCV system ( cap, rotor, wires, removed injectors, coil, vacuum tree/lines/elbows, etc) because I had touched the fuel, spark, vacuum systems I was at a loss on why I did not start back up.

The metal clip that held the PCV hose/pipe in place had been placed under the intake manifold between gasket and intake manifold. It caused a big leak and the carb spray let me know where to check.

[erikv11]

It's all been said but I'd check (1) rear cam seal under the distributor cap and then (2) vacuum leaks, vacuum leaks, vacuum leaks.

[dmechnic]

Haven't touched it the last two days. Picked up a better OBD scanner and cylinder compression guage. It's had an oil leak since we bought it nearly 2 years ago and the daughter, who has taken small engines in high school, has been very remiss keeping up with its maintenance. That backfire out of the open plug has me a bit worried so I just want to make sure something serious (rings,valves, bores) aren't FUBAR. We picked it up for $1k and it has issues so if it dies it's not a catastrophic loss, but I know these things are tanks and will keep going with even minimal upkeep so I'm still going to try to get it going again, especially since it decided to stop running while in the driveway. I just saw another thread where same year/model died, won't start, and he lost the vacuum line going to a freeze plug on the passenger side intake manifold. My next step is going to be chasing the vacuum lines (especially since I had one busted elbow already) after I check the compression values. Will definitely keep all posted. Hopefully I will have an "ah-ha" moment to report back instead of just an "I jiggled this, removed and reassembled that, and now it runs". Thanks for all the input.

[dmechnic]

Getting under the hood today. Plan now is to trace/inspect all the vacuum lines, get the distributor back together, and pray that I find a bad line or two that will miraculously bring her back to life. Oh, one thing...I checked the compression values. Let's just say they were not inspiring:

#1 = 90
#2 = 120
#3 = 50
#4 = 160
#5 = 65

Yeah, not good news at all, but I will hold some hope as this was on a cold block (around 40F)

[abscate]

Note that the misfire codes poorly correspond to the problem cylinders. This is common and almost guaranteed if there is more than one misfire reported

[precopster]

Replace the rotor. They have caused me and many mechanics to misdiagnose and throw parts at the problem.

They have a 2K internal resistor hidden by epoxy that breaks down under load.

Do cylinders 3 and 5 give better values with some oil?

[dmechnic]

Did not bother with the oil test because I know how badly the car's been treated. After looking at the info with the gauge I now realize that it'll tell you whether its a ring/bore vs valve issue. Gave up trying to check the vacuum lines. Without it up on a rack it's a PITA trying to wriggle under, trace what I'm looking for (especially since I don't know specifically what each is for/does) and without a second person to stay up top I simply was way over it by the time I started on the second line that comes off the purge valve on the fan shroud that drops down and eventually heads back to the canister which I am guessing is in the back of the chassis since that's where the line heads. The lines I can "easily" see all look in ok shape but I know that's not saying much.

I took off the fuel rail, cleaned it up, reinstalled. Cleaned the inside of the distributor with electrical cleaner and reinstalled. Put the plug wire harness back in and hooked up. Cleaned the MAF with appropriate cleaner and reinstalled airbox. This is all to say I did not repair/replace anything else...just cleaned and reinstalled. Fired right up. Go figure. Let it warm up and then took it around the block. Can't push it but can drive fine Ms Daisy style. Aggressive throttle threw CEL quickly...misfire codes this time on 1 & 2 and also random misfires. Shut it off, tried restarting and while a little rough it started no problem. It was a $1k car 2 years ago so I'm not really interested in throwing money I don't have at it. Daughter has gotten rather attached so I might give her the option to get it to my guy (who is really great and VERY fair when it comes to $$) and see what he comes up with. Now to order a set of ignition coils for my R...of course it had to decided to act up in the middle of this project.

[dmechnic]

Decided to check and see if by chance the turbo was dead/seized, thus limiting intake air so disconnected the output tube and tried to run it sans MAF as I had to pull the top of the air filter box to get to the front hose clamp. Started, ran rough understandably but was getting a breeze out of the turbo so at least it spins. It died before I could get back in to shut if off, put everything back in and tried to start it again. Again, won't catch. It was trying but misfires were keeping it from sustaining. Suddenly I get a "POP" and a nice huge plume of smoke comes out from the back near the firewall. I continue to try to start it and I get what I can only call what looks like an old steam train smoke stack plume coming from further forward but I could see exactly from inside the car. If I were to guess it was either about where the PCV tube is near the oil fill cap. With determination I was able to finally get it going, still getting multiple misfire code, and when slowly increasing the rpms (so not to bog it out) it start to develop a vibration around 2500 that gets very substantial by 3500 which is far as I took it.

No idea on the source of the smoke as it literally filled the back of the engine bay. I would expect everything is sealed/closed so if anything it should have come out of the tailpipe. Feels like I'm going down a rabbit hole with this thing.

[Chuck W]

So, did you ever check out the coolant temp sensor?

I don't see that as causing the car to die while running, but I had one give me fits on my '97 T5. (EDIT - thinking back, it did stumble and die on me once, before I fixed it)

Car was hard to start, would run rough, etc. It eventually backfired/popped a couple times on me and belched out the cloud of smoke like you experienced. It was throwing all kinds of cylinder misfire codes, like yours.

The issue with mine was corrosion on the ECT sensor connector.

After that "pop" and smoke show, I bet you're going to find a PCV hose blown off, or that you've pushed the rear cam seals out.

Your cold compression test probably gave you bum numbers, at least hopefully.

Check that sensor and its connector. Clean up the connector pins, and check resistances of the sensor. Try to start it again, if the sensor is in spec.