No Sparks... No Idea what to do... Topic is solved

MDK · Post by **MDK** » 09 Jul 2018, 05:17

MDK here... just have to go through it... system by system. It seems you have spark. Are you sure it's not fuel related? I hope you get the mystery out of this car. Be interested in what it turns out to be.... you really need some kind of scan tool to at least point you in the direction. ....

Post by **erikv11** » 09 Jul 2018, 07:12

shihabafi wrote: 09 Jul 2018, 04:30 It can't be the MAF. I've tried it plugged, unplugged, upside down, you name it. I highly doubt that it's the MAF...

Good move, it's not the MAF.

Have you checked out the fuel pump relay? Super common problem on these cars at this age, and it would fit the symptoms of starting only sometimes then rumbling to a stop.

You've confirmed you have spark from the coil to the cap. You can also confirm each cylinder is getting spark by unplugging each wire at the spark plug, and seeing if you get a little spark to jump to ground while you are cranking the engine. It seems like the only reason you wouldn't be getting spark at the plugs is if the wires were bad, but worth checking just to rule it out.

shihabafi · Post by **shihabafi** » 09 Jul 2018, 10:52

I know it's not the fuel pump, because I disconnected the fuel rail hose (the metal one) and tried turning on the car, I got lots of fuel to say the least.

I feel like it's not spark because I pulled out the spark plugs wire and hooked it up to another plug, then grounded the outside and tried turning the engine, but got nothing...

Post by **abscate** » 09 Jul 2018, 11:39

shihabafi wrote: 09 Jul 2018, 10:52 I know it's not the fuel pump, because I disconnected the fuel rail hose (the metal one) and tried turning on the car, I got lots of fuel to say the least.

I feel like it's not spark because I pulled out the spark plugs wire and hooked it up to another plug, then grounded the outside and tried turning the engine, but got nothing...

You need to check the fuel pressure at the rail with a gauge - if your pump is putting out 80% of spec, it won't start.

If you don't have the gauge , use starter fluid to diagnose a fuel delivery problem.

MDK · Post by **MDK** » 09 Jul 2018, 16:56

Hey ..MDK here. I read your last post and I'm glad you got to the bottom of it. Man, what a bummer....a new part ends up being defective. It's happened to my friend Doc who is retired now. Had an independent shop but is a certified Volvo tech. Installed a brand new rebuilt alternator on an XC90 4.4 ... and had to take it all apart again because it was defective....uh it's like a punch in the gut. I'm glad you got it man...

shihabafi · Post by **shihabafi** » 09 Jul 2018, 17:00

but... I didn't get it to work yet...

Post by **erikv11** » 09 Jul 2018, 17:30

shihabafi wrote: 09 Jul 2018, 10:52 I know it's not the fuel pump, because I disconnected the fuel rail hose (the metal one) and tried turning on the car, I got lots of fuel to say the least.

I feel like it's not spark because I pulled out the spark plugs wire and hooked it up to another plug, then grounded the outside and tried turning the engine, but got nothing...

I didn't say the pump, I said the relay. But see abscate's point and yeah it could actually be the pump. To test the fuel relay, jumper it while/when you are troubleshooting. That doesn't address or test all of the fuel delivery issues like fuel pressure, but it does take care of the relay.

When you say " then grounded the outside and tried turning the engine, but got nothing " does that mean there was no spark? I can't figure out what you are trying to say there.

MDK wrote: 09 Jul 2018, 16:56 ... I read your last post and I'm glad you got to the bottom of it. ...

MDK, what are you talking about? His last post says he doesn't know what's wrong.

MDK · Post by **MDK** » 09 Jul 2018, 18:24

Whoa!!!... I thought I read he had a bad fuel injector relay... I apologise guys..it was the othher 850 ..crank but no start...

shihabafi · Post by **shihabafi** » 09 Jul 2018, 18:26

I grounded the outside of the spark plug (thanks Scotty Kilmer) and saw no spark, so I'm assuming I don't have any sparks.

Regarding fuel pump, I hear the buzzing when I put the key into the run position, and also when I yanked out my 3k-mile spark plugs, they were a crispy black, so that's why I believe that I don't have a fuel issue...

Post by **Clemens** » 09 Jul 2018, 23:32

This isn't church. It's not about believing. It's about knowing.

You HAVE to verify that you have no spark. Check every single spark plug. If you get spark at the plugs you have ignition.
Did you seat the fuel injectors into the rail properly? An air leak there could cause trouble.