Ticking, bogging, and running rich

[ehacker01]

A problem has arisen in the last 2 days with my rb25det. here is everything I can tell you

It has a medium volume ticking coming from the engine bay after getting on it. Goes away after 30 seconds

It only happens when hot. I don't mean when water temps are hot, but after driving for 1+ hours.

Has a split second bog/misfire at random rpms above 3500

Runs way richer than normal...reads somewhere below 11.0. I normally run 11.2-11.6

Tick changes with rpms

Tick seems to be coming fromsomewhere at the rear of the motor and is louder than your normal injectors ticking but sound similar...just louder

vacuum at idle is 19-20 always, ticking or not

I am running a walbro pump, stock regulator and injectors, stock everything really. boost is @ ~7psi.

What could it be?

[ehacker01]

By the way. I don't know if this has anything to do with it or not but by the time its hot enough for this to happen, my MAF is HOT, metal around the filter is HOT and piping is hot.

[240sxed]

Wierd maf is hot? like burning hot ot just warm?

Try your plugs, sometimes your plugs may cause not all of the fuel to be burned. Also, hows your fuel pressure

[ehacker01]

maf is hot but not like "its gonna melt, hot" but warm. Basically I was trying to get at the fact that all the intake tubing was pretty warm...maybe it's running poorly from heat soak. by the way does the RB use a intake temp sensor like the ka?

I was gonna change plugs saturday. and my fuel pressure gauge only goes up to about 15-20 (its for carbs).

[Carl H]

have you checked timing?11:1 is waaay too rich at idle........its proly way retarded, i would guess that its off and causing the bogging and miss.also could be a bad ect sensor, where the ecu thinks the engine is chronicly overheating and is dumping silly fuel...

[ehacker01]

I'm sorry. I meant that it was 11.X at full boost above 3000. at idle it is a very steady 14.7-14.9.

[ehacker01]

Ok so its worse today. It started after only 10 minutes of driving. It is almost like it is losing spark up top. In 2nd it would hiccup every 500-1000 rpm above 4000 until redline. but in third I couldn't get it past 6300rpm it would just hang right around 6300-6400 and spit and sputter running richer than 11:1. My plugs will be here tommorrow so I'll look at those when I change them. What could the ticking be though? What are the symptoms of an injector failing/sticking open? Could the coil pack be going bad? Is there a way to check the coil pack?

[Carl H]

have you pulled codes yet?if not i almost am willing to put down money that the engine coolant temp sensor is dead.usualy the remedy is a new sensor, and a reset of codes.

[ehacker01]

no codes present. just checked them today. gonna change the plugs right now.

[ehacker01]

The plugs looked fine but I changed them anyway. Same problem still. It runs fine the first pull but the second 20-100mph pull it still did the same thing. starts missing out up top. Now here is the wierd part. I turned it back down to stock boost (went from 7 to 5.5psi) and it didn't miss out at all.

It still had the loud ticking noise. didn't seem to be coming from the injectors though, more like the valve cover but I can't be sure.

Any ideas. I can't figure this one out.

[ehacker01]

can anybody help me at all?

Could the valves/lifters be getting a little loud after a high rpm run because of lack of oil?

Could my MAF be maxed even though the SAFC only sasy ~85-90%

Injectors sticking, maxing out, clogging, etc?

Something I am apparently unaware of that could have popped off or come loose causing a boost leak at upper rpms?

Is there a way to test coil packs?

Just naming off things to check that I haven't yet.

[Carl H]

have you checked the ECT sensor yet?more often than not it will start to sporadicaly go out but wont trigger a code.....

[ehacker01]

no I haven't. Where is it and how do I check it. Is it the coolant sensor at the water neck with the two wires?

[ehacker01]

checked the ECT today with the nissan consult port. I had a nissan tech sit passenger and watch it. It was fine. timing was fine. everything looked good but it was still missing out.

[ehacker01]

One thing that was really weird. We took off the filter because we thought maybe the stock rubber turbo inlet piping was collapsing from vacuum. When we took it off it ran SUPER rich. I would have thought it would run leaner without a filter.

I am baffled.

[Carl H]

this sounds silly but do you have a stock exhaust or even a cat still on the car?drop the exhaust and take it for a drive and if it improves then there is a blockage in the exhaust some where.

[ehacker01]

No I have a 3 inch dump pipe back exhaust. I think I might have figured it out though. I wired up my z32 MAF and retuned and it seems to have either stopped or become very small misfires. I need to run it a bit more but I think I may have cured it.

[ehacker01]

Ok, I was wrong. Its still missing up top.

Could the stock BOV be worn out causing it to leak at higher boost. Like I said earlier it runs perfect @5.5psi but not @ 7-8psi.

Also why would I have to remove more fuel with higher boost? I figured I would add more fuel at higher boost.

[ehacker01]

So, for the sake of people that are searching for answers to similar problems I will give an update (I hat finding a thread that is exactly the info that I need but was never updated with answers).

The ticking ended up being a collapsed lifter. I think they are the same as the Z32 but we'll see.

The misfire was cured by one of two things that were tried simultaneously. I put new coil packs on and gapped the plugs down to .025

I can now hit 10psi YAY... Way better than 6psi