Nade Posted November 12, 2012 Share Posted November 12, 2012 (edited) Hey guys, I tried searching this up with the search function but I wasn't having any luck (I'm on an iPhone), so I was hoping if I posted up maybe someone knows what's up. Here's my problem, it started a month ago with the truck bogging out when cold and having a rough start from a dead stop. Then it eventually just did not start altogether. Couple raps on the tank and off it goes, so I put a new (used) fuel pump in, and it starts fine now, but it still bogs out when cold and rough starts... However, I have a new issue now, when I am going above 60km/h to 90km/h and coasting at any speed in that range, the truck gets 'stuck' at 2000 rpm and shakes badly, can feel it in the steering wheel. I have to hammer down and force the automatic tranny to shift to make it go away. It never did this before the new fuel pump, but honestly I can't be 100% sure because I wasn't driving it a whole lot since it started messing up, as I got laid off around the same time (isn't that the way, truck breaks when I run outta work). I am going to be checking tranny/motor mounts tomorrow... but honestly I just don't really know where to start. I don't want to think it's the tranny, but it could be a real possibility, as it feels like it gets caught up in a certain gear-range and chugs until I force it to shift.. But I hope it's a stupid sensor or something... Really need some advice on this one. As I said I ran outta work and getting more sucks without wheels. Am driving a gas guzzling van in meantime and it's killing me on fuel. Thanks, Nade p.s. - The truck WAS hydrolocked 7 months ago but I drained vast majority of water and did new air filters and plugs etc before I restarted it, and it's been fine for awhile so I think it's unrelated but might as well mention it. edit--- almost forget the important stuff... 1993 Pathfinder 3.0L XE 4x4, automatic. Edited November 12, 2012 by Nade Link to comment Share on other sites More sharing options...
Leo94 Posted November 12, 2012 Share Posted November 12, 2012 You can start by checking your codes, it sounds like the common coolant temperature sensor. When was your fuel filter last changed? Link to comment Share on other sites More sharing options...
Nade Posted November 12, 2012 Author Share Posted November 12, 2012 (edited) You can start by checking your codes, it sounds like the common coolant temperature sensor. When was your fuel filter last changed? 6 days ago when I did the fuel pump. also did oil change, air filter, checked all other fluids and topped up if need be. I pulled spark plugs to check em all were good only 10,000 oil. regapped one as it was a nerd off. I will try checking codes tmrw AM, although engine light has never been on. Thanks edit - come to think of it, the tempature gauge gets shaky sometimes and dances up and down. Edited November 12, 2012 by Nade Link to comment Share on other sites More sharing options...
Trogdor636 Posted November 12, 2012 Share Posted November 12, 2012 There are more than a few codes that it can throw without the CEL ever coming on. Start there first and then go from there. Link to comment Share on other sites More sharing options...
silverton Posted November 12, 2012 Share Posted November 12, 2012 Does the engine actually stick at 2000 rpm? Or does the gauge stick? Its not common for a square dash (87-93 MY) cluster to fail, but I suppose it could happen. Might look in to the fuel pressure regulator as well, just seems weird that it only happens at a certain speed. Just because the CEL doesn't light, does not mean there is not a stored code. It does sound very similar to what a bad or failing CHTS (cylinder head temperature sender) would do. Link to comment Share on other sites More sharing options...
Precise1 Posted November 12, 2012 Share Posted November 12, 2012 Have you done the obvious underhood inspection to make sure no wires or vacuum lines are unhooked or compromised, all connections are in place, no vacuum leaks, etc? (in addition to checking the codes... ) B Link to comment Share on other sites More sharing options...
Nade Posted November 12, 2012 Author Share Posted November 12, 2012 Okay just checked and it threw only one code. 34 - Knock Sensor. silverton - It will stick to 2000-ish and shake. When I force the tranny to shift it will jump to 3 or 4 grand and run smooth. Next question, is the knock sensor code a bad one to get? :S Link to comment Share on other sites More sharing options...
Nade Posted November 12, 2012 Author Share Posted November 12, 2012 B, yes the mud holds everything together down there.... I did check to make sure all connections were plugged in. I checked everything I could see it was all hooked up. I even cleaned the motor sort of lol Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 12, 2012 Share Posted November 12, 2012 Well, there aren't any good codes... the knock sensor code can put the engine into 'limp home' mode, which limits the engine to 3000 RPM, if it looks like the engine is knocking due to pre-detonation. IIRC it needs to get above a certain level for the computer to go into limp mode? It's clearly not in limp mode, but the sensor code suggests that the steering wheel isn't all that's shaking. I suspect you have a timing issue, which is making the engine fire wrong, setting off the sensor. Link to comment Share on other sites More sharing options...
Nade Posted November 13, 2012 Author Share Posted November 13, 2012 Well, there aren't any good codes... the knock sensor code can put the engine into 'limp home' mode, which limits the engine to 3000 RPM, if it looks like the engine is knocking due to pre-detonation. IIRC it needs to get above a certain level for the computer to go into limp mode? It's clearly not in limp mode, but the sensor code suggests that the steering wheel isn't all that's shaking. I suspect you have a timing issue, which is making the engine fire wrong, setting off the sensor. Yes, I've done some research on it and called the dealer even. Dealer mechanic doesn't know what it is, but did mention that in 99% of cases the knock sensor gets set off it's by something and not the sensor being defective. In 10 years he said he's replaced only one. So I have two conclusions so far... Neither very good. First is that the timing is messed up and needs work asap... But I don't know why it would only mess up at a certain speed... Everywhere else in my driving range is fine.... Which sort of led me to my second conclusion. The torque converter is on it's way out, which totally blows. I got some Lube Gard for it to see if that might help... If it is the torque converter I'm probably looking at a new vehicle. Other than that diagnosis, I'm not sure what else it could be.. Link to comment Share on other sites More sharing options...
Precise1 Posted November 13, 2012 Share Posted November 13, 2012 Dealer mechanic doesn't know what it is, but did mention that in 99% of cases the knock sensor gets set off it's by something and not the sensor being defective. Exactly. What condition are your cap/rotor/wires in? I had a strange stumble in my first pathy and it was because the center electrode in the dizzy cap was gone; it was arcing down to the rotor. Stumbled at low rpm, ran fine about 2000rpm up. You might want to check the TPS output also. Don't borrow trouble yet, it could still be something minor. When it was hydrolocked, did it gulp water and outright die or did it just sip and stumble? B Link to comment Share on other sites More sharing options...
Nade Posted November 13, 2012 Author Share Posted November 13, 2012 . When it was hydrolocked, did it gulp water and outright die or did it just sip and stumble? B One of the stupider things I've done for sure. It gulped it down and died outright. Cap rotor and wires are all new since after the hydrolock. I replaced and flushed every part I could think off. So pretty new. I can pull it again and take a peek. Where would I find the TPS? Link to comment Share on other sites More sharing options...
Nade Posted November 13, 2012 Author Share Posted November 13, 2012 (edited) Pulled the cap, it had some minor white deposits on the outer electrodes, center one fine, cleaned all leads and reinstalled... Found the TPS pretty easy, how do I check the output though? Also pulled air intake off to look inside at the throttle plate it's all clean and shiny still. edit -- I also read somewhere that it might be the auxialiary air valve. I've found where that is as well but not sure how to check it. Cheers Edited November 13, 2012 by Nade Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 15, 2012 Share Posted November 15, 2012 The factory service manual should have a test procedure for the valve. Link to comment Share on other sites More sharing options...
silverton Posted November 15, 2012 Share Posted November 15, 2012 I recently pulled the engine out of my 95, and I recalled this thread about you having a knock sensor. and I got to thinking, since I have a 95, last model year of the chassis, my truck should definitely have all the goodies! My truck does NOT have a knock sensor though. I'm fairly certain it's a Cali emissions truck too, so with all their smog restrictions, i should hope it would have one. Link to comment Share on other sites More sharing options...
Trogdor636 Posted November 15, 2012 Share Posted November 15, 2012 Somebody else went through the trouble of removing everything to check their knock sensor only to discover it wasn't there. My 94 has one, or it keeps throwing a code for it anyway! Link to comment Share on other sites More sharing options...
Nade Posted November 16, 2012 Author Share Posted November 16, 2012 Hey guys thanks for all the tips... Turns out it was a clogged Catalytic converter even though the thing was almost new.... I just bored it out... It's on craigslist for sale now gonna swap it for a hardbody with a 5-speed Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 17, 2012 Share Posted November 17, 2012 Sounds like it was running rich... Link to comment Share on other sites More sharing options...
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