1998 V70XC w/Random misfire

Post by **erikv11** » 09 May 2016, 18:42

Are you asking about the silver, cylindrical part? That's the fuel pressure regulator.

Post by **shiloh51933** » 13 May 2016, 16:53

erikv11 wrote:Are you asking about the silver, cylindrical part? That's the fuel pressure regulator.

Yes.
I thought the FPR was on fuel rail, the FPR on my '96 850 was on fuel rail. What the hell is that valve on the fuel rail then? Now that I think of it that valve on fuel doesn't have a vacuum lines, duh!!

Post by **shiloh51933** » 13 May 2016, 16:57

I exchanged my o2 upstream sensor today, the tip was bright orange red color. What does that? I put 93 octane with a little octane boost and I added seafoam to gas tank a few times.
LTFT seems to be pinned at 0.0%, WTF!!
I can't find any vacuum leaks.
Morning start takes 2-3 tries w/delayed cranking
I'm just turning on and off a few times without cranking starter to prime fuel system.
Fuel pressure is 38psi running.

Post by **abscate** » 13 May 2016, 18:47

Fuel damper is on the rail. That takes the pulses from the pump and smooths out the pressure fluctuations.

Song just solved a tough misfire problem finding an intake manifold problems

Post by **rspi** » 14 May 2016, 08:47

Where is that dead horse that I'm supposed to beat?

OEM ignition parts solve most random misfire issues on these cars.

The PCV will not cause misfires.

Post by **shiloh51933** » 15 May 2016, 18:17

rspi wrote:Where is that dead horse that I'm supposed to beat?

OEM ignition parts solve most random misfire issues on these cars.

The PCV will not cause misfires.

Not in my case, my wires were only 14 months old but I swapped in new set of bougicord, Bosch o2, Bosch cap/rotor, air filter and new NGK plugs. MAF is newish, newish OEM purge valve, newish OEM turbo control valve, ect...
Delayed cold start, she runs good once she get to operating temp, idles better at operating temp.
I'm stumped!!

Post by **rspi** » 15 May 2016, 20:19

NGK plugs are not OEM. What brand is the MAF? Have you checked the manifold for leaks?

Post by **sleddriver** » 16 May 2016, 20:36

shiloh51933 wrote:Here's whats going on; I have a misfire on cylinder #5 mostly but if I don't erase the CEL eventually the ECU will record a misfire on cyl #2 and/or cyl #3. I get a code for cylinder #5 then eventually a code for Random misfire and a code for the SAS system. I can't find anything wrong with ignition system, fuel system and vacuum. I have new NGK spark plugs, new wires, new cap/rotor, New MAF sensor, new Cam sensor, New Boost control solenoid, new NGK o2 sensors and I've replaced or resealed all the wiring underneath the hood. The Fuel Pressure is steady at 38psi, she has spark and I can't find any bad hoses or clogged vacuum hoses.

Search on my previous posts re: ignition wires intereferring with camshaft & crank sensor wiring just below the distributer. Cyl #5 wire needs to be at least horizontal, preferrably angling up. Check RSPI's posts as well.

shiloh51933 wrote: Here's what I did find though; I've been having issues with crank case pressure trying to find it's way out through my rear Cam seals which popped off twice since replacing them w/factory rear Cam seals. With that being said I started checking my PCV system to find smoke coming out of my dipstick tube while the motor is running at operating temperature. The PCV system was updated once in the vehicles life but I don't have an exact date on that service, so I'm thinking it needs to be serviced or replaced again. Any thoughts?

If the pressure is sufficient to pop your cam seals out TWICE, that's major. I suggest you crack the oil dipstick OPEN so that the pressure doesn't build up untill you fix this.

Post by **sleddriver** » 16 May 2016, 20:42

shiloh51933 wrote:Here's the only other issues I have found for sure; Evap-I can't fill tank with gas properly as it constantly sets off auto stop on gas pump.

Your tank is not venting. Either a hose is pinched or collapsed or the SHUT-OFF valve is clogged or stuck closed. If air can't escape from the tank as it's being filled, it'll cause the gas pump nozzle to shut off.

Smoke is the easiest way to troubleshoot. Ask me how I know (finally).

Post by **shiloh51933** » 17 May 2016, 06:10

sleddriver wrote:
shiloh51933 wrote:Here's whats going on; I have a misfire on cylinder #5 mostly but if I don't erase the CEL eventually the ECU will record a misfire on cyl #2 and/or cyl #3. I get a code for cylinder #5 then eventually a code for Random misfire and a code for the SAS system. I can't find anything wrong with ignition system, fuel system and vacuum. I have new NGK spark plugs, new wires, new cap/rotor, New MAF sensor, new Cam sensor, New Boost control solenoid, new NGK o2 sensors and I've replaced or resealed all the wiring underneath the hood. The Fuel Pressure is steady at 38psi, she has spark and I can't find any bad hoses or clogged vacuum hoses.
Search on my previous posts re: ignition wires intereferring with camshaft & crank sensor wiring just below the distributer. Cyl #5 wire needs to be at least horizontal, preferrably angling up. Check RSPI's posts as well.

shiloh51933 wrote: Here's what I did find though; I've been having issues with crank case pressure trying to find it's way out through my rear Cam seals which popped off twice since replacing them w/factory rear Cam seals. With that being said I started checking my PCV system to find smoke coming out of my dipstick tube while the motor is running at operating temperature. The PCV system was updated once in the vehicles life but I don't have an exact date on that service, so I'm thinking it needs to be serviced or replaced again. Any thoughts?
If the pressure is sufficient to pop your cam seals out TWICE, that's major. I suggest you crack the oil dipstick OPEN so that the pressure doesn't build up untill you fix this.

Thank you so much for all the responses.
I'll check #5 wire again but I moved Cam plug away from dizzy. I'll pull dip stick up enough for it to breath.