lots of codes... advice on where to start.

[Jaegze]

I sprayed it today had battery charged and engine basically together.

Engine getting closer to firing. After spraying I pops off a little more but not starting. Maf is like 27$ so I’ll order a cheap lunch be to diagnose. I pulled out one of the plugs and it’s time for a change so I’m going to order those all and give it a shot.

I appreciate the help. Now going through this I had issues in my 280zx similar to this that was maf. We will see. I think stuff will be here tomorrow.

[g300d]

Hope this round of work gets it fixed!

In my case, I unplugged MAF first to confirm it was the problem because I'm a cheapskate and didnt want to buy till I was sure lol!

But for $27, good price! It was way more when I did mine so there's that.

[Jaegze]

When I unplugged the maf there was no change in the way the car acted. Does this mean the maf should be ok?

I pulled the plugs and they looked well used. I am going to replace those and go through and check all vacuums with smoke test and make sure it’s good on that end. This is a newer x5 to me so haven’t gone through it before.

[g300d]

In general no change when you pull the MAF means it isnt related to the problem at hand.

Have you tried clearing all codes, attempting to start, then read again to see if anything gets stored that might point to what's preventing the engine from starting?

[Jaegze]

Yes I cleared the codes and they have not been back.

I am wondering if it could be the fuel pressure valve or filter?? I ran an independent line off the pump into a bucket and it pumped strong into a bucket for about 5 seconds. I had shut the key off.

I hooked a fuel pressure gauge up and got no pressure but I’m not confident the gauge I used for the schrader valve properly as it bottomed out in the fuel rail.

To eliminate any fuel issues.... does anyone know what the fuel pressure should be coming out of the filter? Or thoughts of my line of thinking.

[g300d]

That's new, havent seen anything yet about the fuel regulator causing a no start.

Usually it causes a hard start when it lets pressure drop after engine is shut off, but not a total no-start. Maybe the diapragm is totally torn causing no pressure at all?

Not seen any pressure readings at the filter outlet, just at the shrader valve.

Regulator is by the filter IIRC and might be worthwhile to replace along with the fuel filter and call it part of preventive maintenance?

[bcredliner]

Have to measure fuel pressure at the schrader valve. You can have fuel flow and still have low pressure. Pressure should be 50-52 lbs. However, since you have do have flow at the pump I would expect the engine to at least try to start. I would test at the valve as a conclusive test whether or not fuel has anything to do with the problem.

Based on the codes and testing you have done the problem is more likely the VCT solenoid. It could be the harness or the solenoid itself. The connection could be corroded or contaminated with oil.

[g300d]

Originally Posted by bcredliner

Have to measure fuel pressure at the schrader valve. You can have fuel flow and still have low pressure. Pressure should be 50-52 lbs. However, since you have do have flow at the pump I would expect the engine to at least try to start. I would test at the valve as a conclusive test whether or not fuel has anything to do with the problem.

Based on the codes and testing you have done the problem is more likely the VCT solenoid. It could be the harness or the solenoid itself. The connection could be corroded or contaminated with oil.

Never encountered this before.

Tuning in so I know another area to check when these things stall on me again.

[Jaegze]

Thank you for the follow up. I did end up finally getting a reading at the schrader valve and it was about 54. So that is good.

I went through and cleared the codes again and the maf and cam position sensor came back up.


I’ll look into the vct solenoid and go from there.

I see there are generic tests for cam sensor by seeing if it send me any signal. Do any of these work on these sensors or any test that anyone knows of.

[g300d]

Well, at least it is definitely not the fuel pump. I dont remember if a broken cam position sensor is a no-start. But if they are coming up together (CPS and MAF) it may be a symptom rather than a cause.

You mentioned a new MAF previously, is it on already?