Rough & Infrequent start + Rough Idle & random misfires

[Adrew19]

what's your pressure read on the schrader valve at the end of the fuel rail?
and what kind of gas do you use. brand and grade.

Premium gas usually from Shell or Chevron. New fuel pressure gauge on the way. Mine didn't have a schrader attachment that fit.

I usually just grab a pencil gauge for $1-2; only use it for the fuel/EVAP system and toss it at the end of the day.

I use shell 93 and every time I fill I have to let it crank for longer than usual and open the throttle or it wants to shut off, idles super rough. Do you have a similar experience?

Do you have any way of pulling data, either vida or Bluetooth obd2 dongle?

Yeah I was having pretty similar issues, especially having to open the throttle to get the engine to turn over. It's not even able to start at this point.

I've got an Obd2 but don't have vida. The last shop I took it to (only one I know of in my area that still has Vida other than dealerships) said they ran it and everything looked fine other than a stored camshaft sensor code. Frankly I'm a bit suspicious of how closely they looked into it cuz the car is far from fine. They just slapped a new battery in and said the fuel pump needed to be swapped. So after doing that and the relay, cleaning the injectors, and new plugs the car started getting multiple misfires and now can't start.

Still don't have a clear read on fuel pressure as the gauge I ordered had the wrong size schrader valve and I'm picking a new one up tonight. Tried a Pen gauge but it seemed pretty sketchy at best.

[Adrew19]

what's your pressure read on the schrader valve at the end of the fuel rail?
and what kind of gas do you use. brand and grade.

Tested it last night and got 56 psi.

[vtl]

what's your pressure read on the schrader valve at the end of the fuel rail?
and what kind of gas do you use. brand and grade.

Tested it last night and got 56 psi.

386KPa. Good.

[lrock]

what's your pressure read on the schrader valve at the end of the fuel rail?
and what kind of gas do you use. brand and grade.

Tested it last night and got 56 psi.

good range as vtl said, i usually get between 51-58psi
if you have a somewhat recent laptop (i use a 2018 thinkpad t490 with a 8th gen i7 and 40gb ram, ~100 on ebay) you can run your own vida, which you can download an appliance of for $5 (from volvodiag )it was indispensable for me when getting my car to run again after changing fuel pump/it sitting for almost 10 years. i use a vxdiag tool i got from ebay instead of a dice, i also have a blue tooth one i use with car scanner app for tracking on daily trips, but it won't work with vida

edit to add: Vida was also the only way i could test and troubleshoot my etm as well as testing ones i pulled from yards to see if they worked or not before installing them in my car

[Adrew19]

CPS (crankshaft position sensor) wires go too close to starter, their take interference up from it. ECM can't see crankshaft position and denies ignition. Cutting CPS wires and routing new ones away from the starter helps with that syndrome.

So I re-routed those wires and no improvement. If anything the engine is running a bit rougher.

[Adrew19]

what's your pressure read on the schrader valve at the end of the fuel rail?
and what kind of gas do you use. brand and grade.

Tested it last night and got 56 psi.

good range as vtl said, i usually get between 51-58psi
if you have a somewhat recent laptop (i use a 2018 thinkpad t490 with a 8th gen i7 and 40gb ram, ~100 on ebay) you can run your own vida, which you can download an appliance of for $5 (from volvodiag )it was indispensable for me when getting my car to run again after changing fuel pump/it sitting for almost 10 years. i use a vxdiag tool i got from ebay instead of a dice, i also have a blue tooth one i use with car scanner app for tracking on daily trips, but it won't work with vida

edit to add: Vida was also the only way i could test and troubleshoot my etm as well as testing ones i pulled from yards to see if they worked or not before installing them in my car

Yeah I'm definitely going to need to get set up with vida here soon. Thanks for the tips!

[Adrew19]

So frustrating update here... The car has been at one of the most reputable Volvo shops in the Seattle area the last week and they did discover a few more issues. After doing a smoke test they found a vacuum leak in one of the air intake pipes and replaced that. They also replaced the crankshaft sensor as it was broken/damaged, fixed and adjusted some wiring, and replaced a spark plug (which had broke from me over-tightening it, whoops). However the car won't start at all now after all those repairs, just back to crank + no start. It's getting good spark, fuel pressure, and air and all the cylinders have proper compression... And the worst part is zero codes are showing up so theres no clear hints to what might be going on.

The bill is around $1,100 for parts & labor (only charging 3 hrs even though it was more like 2.5 days) and I'll have to have it towed away this week. Apparently it's completely stumped their whole team of technicians.

I'm going to try and get on the phone with one of the dealer's technicians tomorrow and see how they would go about approaching this situation as I'm not stoked at the idea of throwing more money this issue if it won't get resolved.

[vtl]

Find someone with oscilloscope, crank the engine and read crankshaft position sensor signal (should be clean of EM interference noises). If good - read coil signals.

Also verify everything the reputable shop claims it did / tested.