Odd Misfire Problem

[NoTillCo]

While driving my 99 V70R Laser Blue it suddenly began to run very rough and the CEL, ABS and TRACS light went on.  I got it home and in the garage hooked up the computer and read the DTC P0304.  As a lot of you know it is a misfire in the number 4 cylinder.  Well I did my research and learned it could be a variety of things.  First I pulled the plugs, newer Bosch Platinums,  and sure enough number four was messed up.  The number four plug's electrode was burned up and the plug was fouled.  So, step one I replace all the plugs with Volvo OEM and replaced the coil pack on number four with OEM.  Fired up the Blue and nope still rough still P0304.  Next I replaced the crankshaft sensor.  Cranked it up and no light no DTC.  Problem solved right?  Here is where it gets strange.  I put the car in reverse to get it out of the garage and Blue starts to run rough.  I put it in park and after a couple of seconds it smooths out.  I hook up the computer and P0304.  I clear the code and let it warm up and it is running smooth even when I run it up to 4K RPMs.  The code does not come back, but as soon as I put it in gear to take it for a spin it starts to run rough again.  Sure enough it throws a P0304.  I then replace the Cam Shaft Sensor.  That does not solve the problem.  

 

In short the problem is no misfire when the engine is not under load.  As soon as the engine goes under load it runs rough and throws P0304 and I am at a loss as to what the problem is.

[flyfishing31568908306]

just spit balling.  Looked at your maf lately?

[NoTillCo]

Thanks for the thought.  I would be surprised if it was the MAF as I replaced it less than 10k miles ago.  I had someone suggest it could possibly be the spring in the coil pack boot.  The person said their four runner was having the same problem and the problem was fixed by replacing the spring.  Which would surprise me because I replace the coil pack on four.  The other thought I had was the injector could be potentially malfunctioning.  I hope to have the time to mess around with the car today and see if I can clear it.  If I get it fixed I will let everyone know.

[Big Will]

Any chance the coil you used to replace the original one is also defective? Was it a used one that you replaced it with?

[NEU]

Try swapping coils to see if the problem follows the coil.

 

And did you check the new plug gaps before installing them?

[NoTillCo]

Thanks for the thoughts.  I checked the gaps they are fine.  The coil I installed is brand new bosch.  However, I like the suggestion of swapping coils to see if it follow and I will do that and let you know I have a feeling it is not the coil, but who knows.  Any suggestions on how I might check to see if a fouled injector is a potential culprit?  I am willing to spend the $ necessary to fix the problem, but sometimes I feel like I am just throwing parts at a problem which gets expensive at $50 and up a pop.

[NoTillCo]

Really at a loss.  I went ahead and replaced the injector.  Still the same issue idling and running the engine up the RPM's in park no issue, but when in gear just backing out of garage get the P0304 misfire.  Swapped coils around and the problem does not follow the coil.  ARRGH!

[flyfishing31568908306]

just for giggles, disconnect the maf and put it in gear.

[1clean00]

Have you checked the wiring harness and connector going to the coil?  Perhaps when the vehicle is moving the harness connector is getting jiggled enough to cause the miss.  I've had them crumble before and had to secure them with zip ties until i could replace the connector.  Just a thought.

 

Would explain why when its still and in park there is no issue, because the motor is stationary. 

[NoTillCo]

Well, I disconnected the MAF.  The results were a DTC for low voltage to the MAF and no P0304, but the car was still not firing properly.  I could tell the misfire was still there the way the car shuddered when it was put in gear.  Reconnected the MAF and the P0304 returned.  Up next the zip tie trick and tracking down the wiring.  I am befuddled.

[NoTillCo]

Well put the traced wires etc.  No luck.  Put the compression tester to her and a big zero on the tester for the number 4 cylinder.  Well I think I know what the problem is, burnt exhaust valve.  I could do the valve job, but I do not have the time.  So a couple of questions.

 

1.)  How much does a valve job cost?

2.)  Is it worth it?

3.)  Anyone want to buy a 99 Laser Blue?

 

Seriously, not really, I really enjoy driving the beater straight out of the Alaskan oil fields wood getter F-150 everyday, but I NEED a running car and I enjoy driving the Laser Blue when she runs.  But this is getting ridiculous.  

[Big Will]

That sucks. At the machine shop I used for my engine rebuild the head work cost ~$375 and I supplied the valve stem seals. I know there is a company out of Florida that sells rebuilt heads for our cars for ~$500 but I'd go with a local machine shop if you have a decent one in your area. No shipping costs then obviously.

[Ihatespeedbumps]

If you can DIY the job it would be worth it. At minimum you would need to purchase a cam locking tool for the job. If you take it to the shop the repair will run several thousand dollars easy. At my former employer a burned valve job would run 2.5-3k when it was all said and done. That was using genuine parts and replacing almost everything so you had properly running vehicle when it was all said and done. 

 

Up to you. And if you are serious about selling post your location and get some pictures up

[NoTillCo]

Well I love driving this car when it runs.  But over the last about three years the Blue has sat more than it has run.  And I need a running and reliable vehicle that is not an old wreck of an oil field F-150 Ford.  Unfortunately, I need to sell Blue.  I will not have time to do the valve job until the Christmas/New Year Time frame, so I am selling her as is.  However, if I do not get her sold before Christmas I will likely fix her and sell her then at a considerably different price.  I would like to sell her to someone who understands and appreciates these cars.

 

This car is a 1999 Volvo V-70R Laser Blue.  The car apparently has a burnt exhaust valve as it has zero compression on cylinder four and is throwing a misfire code. The ABS light is on, but I believe this is related to the misfire as the light first turned on when the misfire started and the car was immediately garaged and has not been back on the road  to run through the cycle necessary to clear the code.  The car runs, but it is rough due to the misfire.

 

Last January I replace a blown engine in the car with a used engine.  I had put on about 8,000 miles on the engine before the valve problem.  The car has had the following parts replace within the last 15,000 miles:

 

SNABB RIP Kit;

Xeomodex ETM;

IPD TCV;

K&M Air Intake;

Vacuum Lines;

Coolant Reservoir;

Upper Coolant Hose;

Coil Packs;

Crankshaft Sensor;

Timing Belt;

Engine Mounts; and

PCV System.

 

The interior and exterior are in decent shape, but it is a 16 year old car.  The car has a tow hitch on it.  Also, I have a couple of boxes full of miscellaneous parts.

 

The car is located on the Oregon Coast in a small town called Neskowin.

 

I am asking $2,000 OBO.  If I am way off base with the price let me know.

 

 

[matt b]

Sucks to see this. I think your asking price is high. Given the work required on the car, and assuming it's a car that doesn't have new tires, new brakes, etc.... I think it's worth around $800-$1,000.

 

Hopefully you get more, it's such a great color!