Installed new enigne, engine goggie under 2800 RPM Set DTC 174

G&J Auto Mechanic · May 22nd, 2007, 10:53 PM

Ill try to keep the story short ( still probley going to be long). A customer ran his 1997 Pathfinder 3.3 liter engine without oil. He ran it tell it quit. The result being the engine over heated and seized the drivers side camshaft. It was seized so bad it broke the threads of the cam and tore the cam pully off. I have replaced the engine, But had quite a few problems to sort out. After first getting the engine to crankand run every thing seemed fine while at idle. I drove it about .3 miles on my normal test drive cycle. When I reached the first turn the engine total lost power. Even pumping or holding the throttle barely kept it it going at 18 MPH. I managed to get it down a side road away from busy traffic so I could open the hood and see what I forgot to hook up( even professionals make mistakes). I opened the hood and checked everything out. Every thing seemed to be hooked up so I called my boss to tell him I was broke down and need the tools to adjust the timing, figuring I didn't set the timing to factory spec and messed it up by doing it by ear. I got the tools and maxed out the adjustment of the distributor ( at about 40 BTDC). I ran well enough to get it back to the shop but was still running rough.

I pulled up the specs on how to set the timing. I set it to 15 BTDC as the specs had said and it wouldn't run at all so I set it back to 40 BTDC and adjusted the base idle to 1100 rpms as that is where it seemed to run the best. It ran fairly well for about 5 miles then started doing it again. It seemed to be losing fuel pressure when ever I turned. The tank was only at 1/8 a tank so we put about 8 gallons in it. It stoped losing power everytime I took a turn and seemed to run fairly well, but the idle was too high to give back to the customer and it was also setting DCT 325 knock sencer voltage too high/low and 300 random/multi misfire dected. Rarely it would miss once or twice in a row at 40-55 MPH, I normaly took about 5 miles to set DTC 300. I checked the distributor and coil with the test on our ALLDATA computer system. They checked out fine. I also checked all the plugs and they too where fine. I checked the contantiety of the plug wires. The wires where a bit out of range and we replaced them, still no change in the problem. Out of of options we changed the distributor. Now I could finaly set the timing to 15 BTDC and take the base idle down to specs of 750 rpm it would run ok, but I still got DTC 325 iin a short time of idling and 300 back after extended driving. It ran well enough so I could finaly drive it for longer distances and now worry about breaking down. We also cleaned the injecters, but the longer it would run the more doggie the engine became under acceleration. After the engine had been at operating temp and been driven for about 15-20 minutes you pretty much had to go WOT and let it drop into over drive to get it to go,which it seemed to do fine to get it to accelerate. I just just under normal acceleration under 2800-3000 that it was doggie and got worse the longer it ran. After hitting about 2800 RPM it was as if the engines power would kick in and accerate fine, but when it changed gears and idled down it would get goggie again. After alot of adjusting I managed to get it to where DCT 300 no longer sets, but at 50 to 55 MPH in 4th gear it seems to have a dead miss, but doesn't set DCT 300. Engine doggie from 0-30 MPH under 2800-3000 RPM. From here Im just going to list What we have done to try to correct the problem. Now after extended driving I managed to get it to set DTC 174 Too lean bank 2 and still get the goggie acceleration under 2800-3000 rpm that get worst the longer the engine is ran.

Droped gas tank, found excesive sand and very small amouts of rusted water. Cleaned out and replaced fuel pump.

Cleaned injector and check fuel filter.

Replaced distributor, cap ,roter and wires

Checked grounds in engine compartment and cleaned them 4 times( 1 behind each headlight, 2 on top on the intake, 1 on passanger side on finder skirt, 1 on the back of the atlternator,1 on right side of engine block and on the batterey box[main battery ground wire]).

Disconnected and visually inspected all engine connections for pushed back pins or bad connections

Changed the MAF sensor

Ran multipull vacuum leak test including 4 tests with a smoke mechine( no leak detected )

Change PCM and inspected for damaged/ pushed back pins

Preformed full check of knock sensor, tested ok at 77 degrees( 556 omhs ressistance, within range of test), disconnected and drove the car, no change

Ran Pathfinder many times with scan tool connected and running datastream( OBD II) no sensors seem to being doing anything out of range. Watched the O2 sensors especialy.

Checked EGR for sticking hot and cold.

Reset TPS to factor specs

Things of note:

Spark plugs on passange side seem new out of the box after over 100 miles of use, passange side show normal wear for milage.

Can only get into OBDII, even with specified cables it will not let me into OEM. Using Mac tools Mentor scan tool with specified chip 3322 for OBD II and Specifed cables for OEM.

If you can think of anything I could check that might correct this problem or have had this trouble before please post. I'm at my wits end here.

dvdswanson · May 23rd, 2007, 09:52 AM

is it a brand new engine, rebuilt, or a j/y replacement? how is the throttle body? you've done the fuel and spark, air would be next.

G&J Auto Mechanic · May 23rd, 2007, 02:24 PM

I built the engine up from a brand new, long block engine. I ran the throttle cleaner through it no vacuum leaks detected. The engine has plenty of air. It runs fine at idle. It acts like its out of timing til the engine hits 3000 rpm. It has fuel pressure and fire according to specs.

dvdswanson · May 23rd, 2007, 03:55 PM

I had replace my TPS one time and actually installed incorrectly so it wasnt reading right and it acted like a severe misfire until about 2800 rpm. and idled fine. reinstalled and it ran fine after that. just a thought we are human.

G&J Auto Mechanic · May 23rd, 2007, 05:35 PM

I've already ran a test on the TPS and set it to factory specs, which are actualy pretty broad. It said to use a ohm meter on 1 of the pins and set it to .34-.62 ohm and the thing only goes from .14-.84 ohms. I changed the O2 sensor for bank 2 sensor 1 today and it still didnt change anything.

Toolman5523 · May 24th, 2007, 12:29 AM

You will not be able to get into Nissan data monitor using anything other than consult. Are you adjusting the tps off the closed throttle switch, using an ohm meter connected to both ends of the switch and two feeler gauges ? Then reset the memory, so the ecm will learn the new stops. key on 10 sec key off 10 sec up to 14 times untill closed throttle show closed at idle, then breaks just off idle.

golfer · May 24th, 2007, 07:45 AM

Does this only happen while under load or will the engine act up while running and not under load ?

Quote:

Spark plugs on passange side seem new out of the box after over 100 miles of use

Is this the same side the O2 sensor gave the lean error ?

Note the reset proceedure , also , the resistance specs on the TPS is .5k ohms ( 500 ) to 4k ohms ( 4000 ).

G&J Auto Mechanic · May 24th, 2007, 01:40 PM

The engine will only act up under acceleration after engine has been at operating temperature for about 5 minutes. Acceleration feels doggie even when the engine is cold. The longer the engine runs the worse it becomes.

It is giving the lean error on the opposite side.

G&J Auto Mechanic · May 24th, 2007, 07:54 PM

I've reset the TPS using the feeler gage method this time, it helped very slightly but the engine is sill giving me the same problem. I tested the IAC ACC and the other IAC part. Both tested good. I also spoke with a exhaust man about it possibly being a stopped up cat. He told me that couldn't be the problem asthe pathfinder runs better in over drive and if the cat was stopped up then it would run wrost the higher the RPM. Im going to test the MAP sensor tommorrow. Im running out of sensors to test but it seems something eletrical has to be the problem. Unfortunatly it only does this realy bad when the engine is hot and all the tests are for 77 degrees. I dug through 70 of the 102 back pages last night and found a few post decribing this same problem but most didnt give a answer to it or said they where going to get rid /trade in the car. Please post and other ideas you might have because Im running out of them after almost 100 hours of work on it.

**88pathoffroad** · May 24th, 2007, 08:27 PM

You can download a free factory service manual from PhatG20.net if you think that may help. Troubleshooting tips are good to have. If you can't get one from there, let me know, I can get you one.

Silly idea, perhaps the crank sprocket was one tooth off when you installed the timing belt? I did that once and it was REAL doggy until I tore it all back off and put it to TDC...what do you know, one tooth off on the crank end. Cams were both dead balls on the dot. Timing was finicky, but it idled fine. Just an idea.

Toolman5523 · May 24th, 2007, 10:46 PM

How can you get the t-belt out of time? The belts and sprockets are marked. So regardless of where they may be in pointing if your lines line up it's in time.

**88pathoffroad** · May 24th, 2007, 11:37 PM

Ever done a timing belt? Checked for a crank sprocket match-mark on the oil pump? I have yet to see or hear about a single VG engine with a mark for the crank. The Chilton's/Haynes books say it's there but it isn't.

02kelsentra · May 24th, 2007, 11:58 PM

ok ok, now i know you checked it's resistance. the tps has many contacts, depending on how far the throttle is pressed. on your scanner, or your multimeter, it may check fine. however, there could still be damaged contacts in the sensor that you skip over while doing the test, but they're there. try this. for a REAL tps test, get a hold of a snap-on vantage multimeter/sensor tester if you can. it has a line graph for about 30 seconds, you simply hook it up, move the throttle from idle to WOT. watch the screen, and if there if ANY drop at all, the sensor is BAD! i'd almost guarantee that's your problem. tps sensors are very easy to overlook, due to how they work, as are MAF sensors. i don't think you have it off time, if you did, you'd have much more problems than you seem to be having.

G&J Auto Mechanic · May 25th, 2007, 08:40 AM

Its not out of time. Ive checked that. Lucky another pathfinder came in for work yesterday ill barrow its TPS and see if it changes anything

**88pathoffroad** · May 25th, 2007, 01:40 PM

If the belt were off one tooth, the valve timing would be off, not the ignition timing. Not that you were confusing the two, I'm sure you know what you're doing. Just to clarify.