peejay

I'll add, when testing the injectors for resistance, make sure the terminals on the injectors are good and clean before you rule them out as faulty!!! I "had to" replace two injectors, well, once I had them out, and scraped the terminals with a flat screwdriver, magically they showed the proper resistance!

I think each mark is 5-degrees apart, so if the leftmost mark is 0 degrees (Top Dead Center), each additional mark is 5-degrees BTDC (0-5-10-15-20-25-30) Good luck!

And make sure your EGR valve isn't stuck open!

Thought I'd share some pics of the EGR Diverter (Nissan parts calls it a "TUBE GUIDE"). Thanks to all the contributors to this post, it helped me out ALOT, i mean, COMPLETELY!!! First pic shows the diverter location, note the arrow points up. Second pic shows the valve all clogged up! NO exhaust was gonna be recirculated into the intake!!! Third pic shows the valve somewhat cleaned (and all the gunk that came out of it! I used a small flathead screwdriver, shop towels and brake cleaner...a round bristle/bore brush probably would've worked better).

Thanks, Slart... I'm waiting to thaw out from the "Snowmageddon" (ice) here in Atlanta...I should be able to re-run the tests for EGR Function as outlined in the FSM, then I'll report back to you. Having a PROPER understanding of how that solenoid works this time should help me out, I hope it's as simple as a clogged EGR valve, but I need to make sure I'm getting vacuum to the valve, when it's supposed to! (i replaced the 3 EGR vacuum lines not too long ago, one was suspect, and just did the others off GP!)

Slart... you...are...the...man! didn't know a circuit can be switched to behave as positive or negative! (but I still got the CEL, might need to PM you if that's ok!)

Slarti, Thanks for the response! The part about "...vacuum would remain in the line, and the valve would remain open..." reallys clears up why there is an "A" and a "C"! I have but "one last question"...according to the FSM, the EGRC solenoid should receive a ground signal from the computer at 2,000 rpm, and that vacuum should exist at the hose leading to the EGR valve ("B")...this leads me to believe the computer is calling for EGR at 2,000 rpm, which means the EGRC solenoid is allowing vacuum to lift the EGR valve at this rpm? And that under 2,000 rpm (or at high RPM), the computer does not send a ground signal to the EGRC, so that the solenoid does not admit vacuum to the EGR valve? I tested this on my engine, with the voltmeter connected to ECM terminal 104 (for EGRC), battery voltage starts appearing at 2,000 rpm, and returns to near zero at idle... is something wrong with my EGRC solenoid? or is my ECM sending a ground signal at the wrong time? That is, it should be sending the ground signal at rpms of less than 2,000 or greater than, say, 4000?

Hmmm...have you tested the injectors for leakage? Will it start when warm/hot if you give it some accelerator pedal?

Thanks for the response Slartibartfast! I think the FSM has it wrong here, again... On page "EF & EC-16", it says of the EGR Control (EGRC)-Solenoid Valve, "The EGR system is controlled only by the ECM. At both low- and high-speed revolutions of engine, the solenoid valve turns on and accordingly the EGR valve cuts the exhaust gas leading to the intake manifold." And on page "EF & EC-21", it says "...When the ECM detects any of the following conditions, current flows through the solenoid valve in the EGR control vacuum line. This causes the port vacuum to be discharged into the atmosphere so that the EGR valve remains closed. 1) Low engine coolant temperature 2) Engine starting 3) High-speed engine operation 4) Engine idling 5) Excessively high engine coolant temperature 6) CPU malfunction of ECM and camshaft position sensor malfunction" However, the diagnostic/test procedure indicates that the EGRC solenoid is "normall" closed/off, and becomes energized under certain conditions (engine speed at/above 2,000 RPM, wheels in motion)...and the FSM tests would indicate that the EGRC solenoid actually OPENS when energized (by the ECM) to allow vacuum to flow through the solenoid and to the EGR valve, to OPEN the EGR valve, allowing exhaust gas to enter the intake...so instead of the system cutting exhaust gas when activated, it seems like it admits exhaust gas when activated... I still don't get what the port "C" is for...why does the solenoid need two inputs (port A & port C)? Why am I not seeing vacuum at the hose that connects to the intake boot?

Okay, so you guys sound like EGR pros, hopefully you can help me out! I've got a 94 Pathfinder, it has the EGR valve, but not the BPT valve...my CEL is on, and giving me a code 32 (EGR function) and 34 (knock sensor)... My question, what is port "C" for??? And when I perform tests on the EGRC solenoid, i can NEVER get a vacuum gauge to register any vacuum at port "A" (the connetion to the intake boot)...since that port is so far away from the manifold, will it ever register vacuum? The only way I can get my EGR valve to operate is if i connect "A" to the throttle body (a "better" source of vacuum?)...However, my CEL is still on, but I haven't taken the EGR valve itself off and inspected/cleaned it... And you guys who have ditched your EGR systems aren't worried about detonation, knock, or preignition from combustion temps getting too high? Is that a bunch of baloney? The previous engine in this truck detonated BADLY, the ceramic was broken off all the plugs, engine had no power...I'm thinking the EGR system went out, and the previous owner never got it fixed, which caused the detonation? Not sure, but I don't wanna mess up the "new" engine the same way.. Plus, I live in Atlanta, and the sniffer test is a must, unfortunately. Thanks for any help!

ahardb0dy, been hearing alot about those two items, haven't checked them yet! i put a new Oxygen sensor in when i put new plugs in (had to replace the entire exhaust, and couldn't get the old Oxygen sensor out) "51" was the only code...before that, i was getting a "32" (EGR function) but i've fixed that...(it was doing the "dieing at idle" even with bad EGR, though) I will read (and perform) the FSM's test procedure on those sensors and report back, thanks!

Great! Ok, more info: new plugs were put in about 500 miles ago... just did a new fuel filter and new pcv valve about 100 miles ago... i did a "power balance test" recently on the running engine to try and diagnose a slight miss...well, i think that test messed up my injectors! because after the test, those two injectors (#2, #5) were giving me a code 51 (injector circuit)...coincidentally, those two cylinders were the only ones i was able to remove the plug wires on while running! bought two new injectors, replaced those... air filter "looks" clean... throttle body "looks" clean (i haven't looked at the sides of the butterfly to see if it's gummed up) oh, put a can of SeaFoam in the tank about a month ago, too...haven't tried it in the intake yet some google searches said it could be a weak fuel pump? could that be it? i do have FSM (and the Haynes!), they and this website have been of great help! I'll check again for codes... i'll also mention that i do think i can detect a strong fuel smell, not sure if it goes away as the thing warms up or not...could this be a too-rich engine? can an engine ever be too-rich when cold, short of flooding it? Thanks for your replies!

Greetings, all! Got a problem I could use your help with... 94 Pathfinder, on the first start of the day (cold morning), you can crank the truck, it will run for a few seconds, "hunt" for idle, then die...repeat, it does the same thing...usually on the 3rd and later trys, it won't even run... Now, if on the first try, you "feather" the accelerator pedal, it will stay running...after a few seconds of keeping the idle high enough so the engine warms, you can get off the pedal and the truck will idle fine... My thinking is, since I am having to give the engine more air, by opening the throttle plate (via the accelerator pedal), then the engine is not getting enough air when cold, right? (Don't cold engines require more fuel?) So I suspected that the Idle Air Control Valve (IACV)-Air Regulator must not be working properly. It is my understanding that the IACV is supposed to provide a bypass for incoming air...(not sure what it bypasses, i guess the "normal" path for incoming air into the intake?)...Anyhoo, I disconnected the hose from the intake tube of the IACV, put my MityVac pressure pump to it, and pumped it, to see if the IACV was not blocked...no reading on the gauge, and I could hear air coming out of the intake runner ports (this was all done with the intake off), so that makes me think the IACV is ok, well, at least it is open when cold (normal). Also, the engine never reaches a fast idle...i would think if the IACV was not working (stuck open), then the additional air would cause the idle to remain high...once warm, the truck idles at about 700, no fluctuation... Any ideas what the problem could be? My other thoughts are, maybe the engine is getting too much fuel during cold start...and when i allow more air in, i am balancing out the mixture? At what point does the ECM "take over" and control the air/fuel mixture? By that I mean, if I am giving it more air by tapping on the accelerator pedal, is the engine "revving up" because of this additional air ONLY, or is the ECM now being signaled to give more fuel, and that is what is raising the idle? I would think if the problem is too much fuel, then me giving it more air, is gonna give the engine even more fuel, and it would die out?

Ah, methinks you (and g**gle images) are correct, sir! I thought it was something factory that wasn't properly connected! Thanks!

Hi, all This cable/connector is on the driver's side floorboard, what does it go to? Alarm? Radio? Smoke-Screen Activation Device? Thanks! (oh, sorry, 94 Pathfinder!)

ahardb0dy, now THAT circuit makes more sense (I was looking at the cooling circuit for the VG33, i think the flow may be wrong on that diagram!) i cranked the truck, let it run for about 10-15 mins, the upper hose got warm, the lower hose got warmer than cool...gauge started reading slightly above "C"...i'll assume everything is working fine...i'll try and put a few miles on it, and change the thermostat when i do the timing belt! thanks for everyone's help!

Eh, it probably sat there and idled for about 10 minutes (with the radiator cap off)...needle on the gauge rose to SLIGHTLY above the "C" mark...got a few other kinks to work out, then i'll take it around the block to see if i can warm it up "funny" thing is, the level of coolant in the radiator NEVER dropped...in fact, it started to rise, so much so that it overflowed...i put that cap on, and it overflowed into the recovery reservoir, as it should... but that lower hose never got warm! the upper hose was hot, and squishy (i "think" I could feel coolant circulating through it). i will try and rebleed the system this evening, as i'm not quite sure i did it right, and i've got a feeling i should test that thermostat just off principle, and might as well replace it while i'm at it. it seems "werid" to have the thermostat in the inlet hose, as opposed to the outlet, but i guess it works, i just don't know how!!! thanks for the responses!

Okay, guys and gals, sorry to strike further blows to a horse that shows no signs of life, but this cooling system circuit is baffling me! What brings me here today is, after reaching "normal operating temperatures", my lower radiator hose is COLD...either the radiator and fan are REALLY doing their job or coolant is not being circulated, or i've got a bad thermostat? Speaking of that thermostat, what I would really like to understand is, how does its operation (open or closed) affect whether or not hot coolant exits that upper water outlet? Are there some beyond-the-hayn*s-manual physics at play? seems coolant would leave the intake manifold, reach that water outlet, and be sent out thru the top radiator hose whether the thermostat is open or not? Thanks for any insight!

I was able to pull it up, it shows that when the thermostat is open: Water outlet-->Radiator-->Thermostat-->Thermostat housing (Front cover)-->Water pump-->Cylinder block and Heater-->Cylinder head-->Intake manifold-->Water outlet (Heater-->Intake manifold and Thermostat housing (Front cover)-->Throttle body-->Water outlet) I'm used to engines with the thermostat housing serving as the water outlet, i think that's where my confusion came from! When/if I ever get this thing runnin, i'll take the radiator cap off and view the flow, and see if indeed the coolant is exiting the radiator through that top hose!

I read somewhere that the thermostat is always the outlet...hot coolant hits it, and causes it to open, allowing the hot coolant to enter the radiator, get cooled, and then flow back into the engine via the return hose. Since the lower radiator hose has the thermostat, this must be the outlet...which means that the upper hose is the inlet/return. So when i fill the radiator up the "first time", the engine will draw in coolant from the upper hose. Seems backwards, but I guess there's a method to the madness! Thanks, all!

Sorry, one "last" question...so does this mean coolant is forced from the bottom of the radiator [circulates, is cooled, and then goes] to the top of the radiator?

Ah, so the top hose draws coolant, from the radiator, to the engine, and the bottom hose returns the coolant to the radiator (once the thermostat opens)? Totally makes sense if that's the case!

Greetings, all! Let's say you have drained all the coolant from your radiator and the engine block. When you add new coolant to the radiator, and start the engine, how does the coolant get sucked in by the water pump, past the closed thermostat, and into the block? I understand how it works on vehicles where the thermostat is located in the water outlet, but i'm getting lost on systems with the thermostat located in the water inlet! Thanks for any help!

Y'all rock, thanks!!! I apologize for the image hosting, I'm having problems gettin' it to stay linked! If I do make it out to the boneyard, I'll try and sneak some pics of the starter/tranny bolts before I remove 'em, and repost here!

Greetings, all! Need a little help identifying transmission mounting (and possibly starter) bolts! (Shame on me for not labeling them when I took them out!) I've attached a pic to show what I currently have...The 3 in the bag labeled "HIDDEN" are the two flange bolts, one for the driver's side gusset, one for the passenger's side...and the 3rd "long" bolt in the "HIDDEN" bag, I'm assuming goes in the bottom gusset on the driver's side? Are the two longest bolts (with flat washers and lock washers) the starter mounting bolts? Or are they transmission mounting bolts? And so it looks like I'm still missing a bolt or two? Thanks for any and all help, I hafta get a starter from the junkyard, so I can probably ID the bolts then, but preliminary info might help! (Note: Precise1 posted a good pic of the backside of the starter bolts here, http://www.nissanpathfinders.net/forum/index.php?showtopic=1754&st=80, and I think I can make out what looks to be a flat and a lock washer on those bolts, so I'll assume the long, REALLY oily ones I have are for the starter!)