ac max 92

iTrader: (13)

So all of the sudden after the car running great and timing set all of a sudden during a hot week last week the car has started running rough though i don't really think it's temp. related being it's still idling rough when cool. Im kind of stumped at this point but still need to do a little more digging. New coil, wires, plugs, cap and rotor. Injectors to my knowledge are fine. I've pulled all the plug wires etc. one by one and each change the idle. Fairly new vacume lines and had a vacume pressure test done. No vacume leaks. I've done a diagnostic on the ecu in mode 3 and no codes just 55 all normal. Im starting to wonder if it's something electrical but otherwise all sensors and harnesses are conected. Kind of strange this just came up out of the blue with no symptoms before hand. Though one day last week i did notice a very minimal oil leak that appeared to be a cam seal but strangely no leak for a week so far after that day which is weird. Any suggestions? It's a VG by the way.

AzureblueZ

You specifically mentioned that the timing was set. Why?

Has it stayed running that way, or does it only do this periodically?

My 3rd gen VG Maxima will occasionally have 1 injector act wonky on the really hot days of summer. About the time I start to think about replacing it the injector begins functioning normally and stays that way for another year.

Is your weather stripped near the firewall at the top still secure? I get issues when mine is not secured and it rains. Did it rain recently?

Cam seal leak is probably not related and it sounds like you ruled out vacuum issues.

Did you change anything else real recently? Usually when something starts going wrong I ask myself: what is the last thing I changed?

ac max 92

iTrader: (13)

Last thing i changed was the cluster but i don't think that would be related at all. I mentioned the timing was set because i went back to a stock ecu but after the ecu swap and the timing set everything was running well. The problem was pretty sudden and weeks after. I don't have any injector leaks. The injectors are a couple years old but i wouldn't rule out an injector or injector connector being a culprit. I have yet to take a multi meter to see if all the injectors ohm out per spec. though I'll be swapping my 92 fuel rail with square top injectors for the 94 with the oval top injectors since they have a much better connection unlike those rubber boots that deteriorate allowing the connectors to get corroded. I have the lower intake and fuel rail needed for the swap aswell as some new (reman) oem jecs injectors all of which were flow tested so i'll have to see if anything changes after the swap otherwise im wondering if it could be something electrical.

AzureblueZ

I've had a number of electrical issues that have arisen in the last year. They all stem from the deterioration of everything rubber.

It could be that some electrical bit got old and crumbly.

It's been an interesting year for my 3rd gen. I've been replacing lots of seals, vacuum tubes, and electrical connectors. It feels like all of the dang rubber pieces got together and decided to go on strike!

ac max 92

iTrader: (13)

Lol Sounds about right and new harnesses are an arm and leg.