P1313 and P1316 codes EVEN AFTER HEAD JOB!

[Craigness]

My 96 disco runs like crap after it warms up. Robison told me (Almost swore to me) that it was skicking exhaust valves and told me to get a valve job. Well, I got a valve job done and $1200 later the truck is still doing the same thing.

The motor stumbles and runs erratic after about 20 minutes of driving from a cold start. The check engine light is on and the codes are P1313 and P1316 and some others are P0300, P0303 and P0305 (Engine missfire on multiple, cylinder 3 and cylinder 5). I'm running out of money and time. The engine runs rough but at red lights to check engine light will blink and when it does the motor runs good. When the blinking stops, it acts up again.

There is no arcing from the wires. The fuel pressure is fine.

Any idea?

 

[DISCO_TONY]

Evening,

Have you ever changed the O2 sensors? This could cause an issue like that. Well there are a few other things as well, SparkPlugs, Wires, Plugged fuel filter, low fuel pressure.. and the list can go on and on. Start with the cheap item.. New plugs and wires.. Or go to AutoZone and have them read the codes...

 

[baddmojoii]

Possibly bad/clogged injectors or maybe even a fautly VSS.

 

[agro1]

Hate to say it, but it sounds exactly like the symptoms I had...Although you didn't mention if you were loosing any coolant. That is the tell tale sign of a slipped sleeve. Read this thread:

http://www.discoweb.org/forums/showthread.php?t=1704&highlight=sleeve

 

[Craigness]

I doubt it a sleeve...

If it was a sleeve, why would it run great when the check engine light flashes?

Also, I'm not loosing any coolant that I can tell. Light smoke for the first 3 minutes in the morning then nothing. It does smell like its running real rich when it's screwing up....

I tried injector cleaner also and it made no difference. I did the good job too, the $100 job at pep boys, still nothing.

Also, wouldn't that make a rapping noise?

 

[agro1]

If your not loosing coolant, then it's most likely not the sleeve. Lucky you
You spent HOW MUCH on injector cleaner @ PepBoys ?!?!?
If you low on cash, pull a friends plug wires and use them to test for bad wires. If nothing pull the coil pack, check the MAF, o2 sensors, clean your stepper motor, lots else..do a search in the archives if you haven't already.
What color is the smoke at startup ? Like you said, it sounds like your running rich...
You read your plugs yet ?

 

[Craigness]

More interesting news.

Replaced the entire coil pack and all wires. No difference.
Replaced the air flow meter. No difference.

Any ideas? Anyone? Buller?

 

[ptschram]

Any ideas? Anyone? Buller?

Rip the intake off and measure the camshaft lift. After I charged a client near $1900 for a head job and some other stuff, it still had misfires. Turns out the cam had a lobe missing. When the valves begin sticking, it can cause rapid camshaft wear resulting in poor performance and misfires.

Also, if you go to John's site, you'll learn that misfires limited to odd cylinders could be caused by a bad VSS (I was unaware that the ECU only cut the odd cylinders at over-rev conditions until I read it there).

Lastly, the fact that it only does this after warm-up does lead one to believe it could be a sleeve.

PT

 

[Craigness]

Misfires....

I can here slight ticking in the No 5-7 cylinder area even when its started. The truck DOES run great when the check engine light blinks at some red lights. It totaly smoothes out. I still dont think it's a sleeve. Everyone I talked to said that a dropped sleeve would be a loud rapping sound. Also, I can "punch" through the rough running spots with just a little throttle. It opens up like it popping through a flat spot on the TPS (But I know its not a TPS problem). I'm also not loosing water at all. No smoke at all even on start up.

Could I have an injector that is screwing up when it gets hot?

It starts it's "Fit" almost to the minute at about 13 minutes of running from cold. Thats got to be a sensor or injector messing up after it gets too hot.

The O2 sensors come online within 3 minutes, no? I am not gettting any 02 codes.

Is there a way to force the ECU into closed loop mode by disconnecting a sensor or something so it goes into refrence map? I think this will tell me if it's a michnical problem or sensor/ecu problem.

I'm starting to look at Chevy 350 retorfit options, help!

Craig

 

[Craigness]

in addition....

Also, wouldn't camshaft lobe wear be a steady thing? I'm ready to bet the farm that its a sensor or even a defective ECU.

Also, I would suspect that the sleeve would get tighter after the heat would cause it to expand and tighten a bit in the block from the heat difference? I mean the sleeve would get hotter than the surrounding alloy engine and cause it to get tighter.

 

[LR Max]

Did you check the gaps on your spark plugs? I've seen that cause said problems before. Sometimes the spark plugs, new OEMs outta the box aren't gapped correctly.

Try that.

 

[D Chapman]

When the truck is running funny, does the speed-o do funny things too?

 

[Craigness]

speedo

Nope. It's right on the money.

After the thing gets into full screw-up mode (Is gradual after it starts) to the point where it starts to affect highway driving, I can't punch through it anymore. After it's good and hot, it runs so badly, that it's hard to get up to 50 from a standing start. I'ts tempature related thats for sure.

 

[ptschram]

There are only two temperature related sensors, fuel and coolant. Coolant is by far the most common to fail.

 

[Craigness]

temp sensor

I'm not saying it's a temp sensor, but a sensor that might be failing when it gets hot from the heat of the motor. ALSO, yesterday I did a lot of short trips with the car on errands and had the car off for no more than 5-10 minutes each time. Everytime I got back in the car it ran fine for 10-15 minutes before starting its thing. So whatever is the problem is cooling off quickly in 5-10 minutes. This could be a 02 sensor or something that is not right up agaist the motor. A dropped liner would not "Reset" itself so quickly.

 

[ptschram]

The O2 sensors are electrically heated. Let's go back to sensors.

The crank position sensor is a lights out sensor. No crank sensor, no spark.

Cam position sensor, limp home mode.

O2 sensors, complete failure, limp home. Slow response, horrible performance.

Coolant temp sensor-all manner of goofy things start happening.

Fuel temp sensor-usually results in hard warm condition starting, but really doesn't cause much concern when the engine is running.

Air temp sensor-what the fuck is this thing for?

Have you considered driving it until it does its thing and taking it to someone who can read the inputs to the ECU? This might be a very enlightening exercise. More enlightening than what we're doing here.

The fact that the misfires are limited to the odd cylinders leads me to believe it might be the VSS beginning to go bad and giving erratic responses.

Perhaps a can of electronic component cooling spray might be of use here so you could selectively cool components.

Might be a stupid question, but how many miles are on this engine/truck?

 

[xmustang420]

This sounds alot like the problems I've been haveing on my 96 too. First started in the middle of last summer. Dealer wanted to replace the cylinder head and blamed it on carbon build up. I went the cheaper way and just got a valve job, but the problem still persist on long driving or trips in the heat. If it is the same problem I've found not running the air conditon helps and if it starts acting up i turn the heat (windows down of course) on and the defroster. Seems to curb the problem alot and with the windows down it gives a nice refreshing breeze. But anyways my problem is still there...try this and maybe it can help you out a bit b4 you and i fix it all the way.

 

[Chris-St Louis]

Air temp sensor-what the fuck is this thing for?

The Intake Air Temperature Sensor is a dedicated sensor, mounted on the air cleaner housing. The Intake Air Temperature Sensor is a resistive sensor, i.e. the change in resistance is related to change in air temperature. The signal from the Intake Air Temperature Sensor (X311) is used to retard the ignition timing if the air temperature rises above 55?C .


Sorry, Couldn't resist.

 

[Craigness]

Discovery (No phun)!

I (Just for the FUCK of it since we are now cursing....) removed the connector to the coolen temp sensor. The truck started up with a shake (Several shakes) and ran fine. It does nto run perfectly, but ran great for about 20 minutes then I parked it. It seemed to have only about 70% of it's total power, but no hesitation. I did not let the car run long enough to see if it would start screwing up, i'll try that one tomorrow.

Also, there is a welded patch on the odd cylinder side cat. I'm not sure if it's been gutted at some point or even clogged. I had a 90 classic that ran like a box of shit for months untill "Recardo" found the problem in an hour as a totaly blocked out cat. I mean this thing would have passed more air with a tennis ball rammed down its throat. I'm not saying that this would cause this but could a bad coolent temp sensor cause missfires in 5 and 7 enough to cause a meltdown of the cat leading up to all of this? The engine had almost no wear or varnish in the heads when they were done. I have pics of it. They were like alloy colored.

The truck has 98k on it and is dent and rust free.

I also have the perfect solution to the raised dash issue that does NOT use crappy boomarang bullshit brackets. Those rover guys should be ashamed of themselves. Yhats will get me on another rant.

Why do we love these miserable boxes of shit? These trucks are like a wife you wish you never married 10 years ago. They fucking complain all day long but you never dump them. You would rather beat them with a bat at the side of the road then get rid of them. If you don't think i'm on the ball, just wach any epsiode of COPS on TV Sunday nights, just replace every word "Wife" with "Rover" and it all will make sense.

Why did you hit your "ROVER" tonight?? - Officer Bob says.....

"It would'nt stop fucking nagging me, man..... (Drunk redneck bastard)...

"Why dont you get some help or just leave her???"..... Says Officer Bob....

"But, I Love her....."....(Redneck dude is now shirt/pant/blurry assed and face down in the mud...) Fade to the cops logo with some police dispachers raspy voice in the background.... Credits roll.... Fade to black.

We are all programmed little idiots....

 

[Craigness]

NEW Discovery (Errrr)

OK guys, check check it out out.....

I discconected the coolent temp sensor (No check engine light came on, why?).

I put the heat on in the truck with the windows open. I drove for about an hour and NO MAJOR hesitation! The truck stumbled a bit but overall a 85% improvement. Also, the check engine light came on about 35 minutes into driving (Later to find code p1313) but no hesitation even coming off of a standing start at a light. I mean the truck also had only about 70% of its cold start power but no major hesitation.

Do you all still think its a dropped liner now?

What next? The truck still idles like shit, but runs much quieter and smoother. It still misses on a free reve to 5G but does not have the terrible stumbling problems it did with the coolent temp sensor plugged in.

What next?