98 V70 GLT Rough Start, miss RESOLVED bad fuel inj

socompsp · Post by **socompsp** » 17 May 2013, 13:06

when the problem starts unplug the injector for 5 and see what happens

Post by **jreed** » 18 May 2013, 05:10

Taupehat--
Regarding the ignition wires, you mentioned in your first post that "two of the wires were factory originals. Brittle, ugly, wore out, bad terminals, etc. Weirdly, three of the wires were somewhat newer and a different brand." Which kind of wire did you find going to cylinder #5?

taupehat · Post by **taupehat** » 20 May 2013, 10:19

jreed wrote:Taupehat--
Regarding the ignition wires, you mentioned in your first post that "two of the wires were factory originals. Brittle, ugly, wore out, bad terminals, etc. Weirdly, three of the wires were somewhat newer and a different brand." Which kind of wire did you find going to cylinder #5?

A fine question. The two original Volvo cables went to 4 and 5.

Post by **jreed** » 20 May 2013, 16:31

I wonder if it could be that the old original Volvo OEM (Bougicord) wire going to #5 was bad and the replacement Import Direct part is not of the quality needed to prevent misfires. The Bougicord OEM wires are a little expensive but many people have reported having misfires with any wires but Bougicord.

taupehat · Post by **taupehat** » 20 May 2013, 17:42

If one could make a sound effect to indicate a husband sleeping on the couch, buying another set of new plug wires (particularly the spendy ones) would trigger that sound, and thus I'm hoping it's something else.

The one area still unchecked is vacuum, and at this car's age there's probably a really good chance that's at least part of the problem.

socompsp · Post by **socompsp** » 20 May 2013, 20:14

oh yeah, it very well could be, although gross leaks usually trigger an o2 or related code. get yourself a can of carb cleaner and goto town. just be cautious of flammable liquid on hot engine components.

taupehat · Post by **taupehat** » 21 May 2013, 11:47

Part of the reason I'm thinking vacuum is that when it's in its funky mode, when I give 3/4 throttle it pings pretty badly until the boost kicks in. In an older car I'd say the vacuum advance wasn't working right...

Post by **E Showell** » 21 May 2013, 12:31

Plug wires.

socompsp · Post by **socompsp** » 21 May 2013, 16:30

woah wait, its got a "ping" sound? you could have an exaust valve stuck closed. that ping is the extra pressure trying to escape through only one valve. if that is whats going on that can be very damaging to your motor. get someone to drop a borescope in your motor.

taupehat · Post by **taupehat** » 22 May 2013, 11:39

This is not happy news, but sort of fits what I'm seeing. Quick question: how could the valve stick shut?