Persistent Cold Start & Misfire Issue – Need Guidance

[Scott560]

I will try and review the logs later this evening - perhaps even try some logging of my own from my logging tool. You are running the standard management I take it?

You said H22a5, generally the 99 and onwards (mine was a V reg) is the h22a8 engine, not that it makes much difference for diagnosing.

[Jakku41]

I will try and review the logs later this evening - perhaps even try some logging of my own from my logging tool. You are running the standard management I take it?

You said H22a5, generally the 99 and onwards (mine was a V reg) is the h22a8 engine, not that it makes much difference for diagnosing.

Awesome mate appreciate it! . Yeah standard ECU.

Mines V reg too however the block is definitely stamped H22a5. I wish it was the H22a8...

[Vtecmec]

Its hard to tell 100% as you don't seem to blip the throttle once its running (or if you do the TPS shows 0% nearly all the time), though a snapshot of the 3rd run shows that the MAP sensor does not seem to change its reading once running, even though the revs change and I'd expect that to happen.

Run 3.jpg

Also when cranking, the MAP does somewhat follow the TPS, but gets erratic at a point too (see the middle)

Cranking.jpg

I'm no expert but I'd be swapping the MAP sensor to see if that made a difference.

[vanzep]

as it was mentioned that problem started when aem v2 fitted - could this be to with the vac line from map sensor being plugged into the wrong port on the inlet mani - ive done that before and the lude didnt like it just a thought

[Vtecmec]

5th gens tend to have the MAP directly on the throttle, unlike 4ths, so no line to misroute, though it's a good point that a decent sized vac leak would be worth looking into.

[vanzep]

ahhh i am 4th gen biased...forgot 5th gens had different set up.

[Jakku41]

Its hard to tell 100% as you don't seem to blip the throttle once its running (or if you do the TPS shows 0% nearly all the time), though a snapshot of the 3rd run shows that the MAP sensor does not seem to change its reading once running, even though the revs change and I'd expect that to happen.

Run 3.jpg

Also when cranking, the MAP does somewhat follow the TPS, but gets erratic at a point too (see the middle)

Cranking.jpg

I'm no expert but I'd be swapping the MAP sensor to see if that made a difference.

Wow thank you for taking the time to look through the data!

Good spot, I'll have a look into sourcing an OEM spec MAP sensor. It was on my list of possible faulty sensors and can't hurt to replace and see anyways.

As for the vac leak I was thinking that for a while but the fact the idle seems to stay consistent when up to temp made me question it. I've gone back and check the lines I disconnected (and now reconnected with the OEM intake) and everything seemed to be in order. Nonetheless I will probably look at getting a vacuum gauge to check for leaks in the system.