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Joe S 04-17-2011 06:57 PM

URGENT: Old Nuc I need help!
So here's what I did with the car today, what happened, all sorts of good info. I'm lookin for some help...

So installed the Napa fuel filter, replacd oil and tranny fluid and both filters. I also swapped out my belt tensioner. Fluid levels are good. Tank was basically empty. A 40 some odd liter tank and I put in 40L...Car started and ran with no issues

So drove about 10 km to gas station, filled up. Have used this gas station many times with no problems.

Got on highway. Gentle driving, no gunning it. After about 100kmh or so, the accelerator pedal got stuck while I was accelerating. I gave it a bit of a kick and it unstuck...however, car started shuddering and loosing power. Pulled over, and ya, crazy misfire! Engine light ended up flashing at me, so I shut it off and just towed it back to my workspace...

Now...I don't have ym scanner so I can't pull the codes. I am going to check spark, my plugs, as well as do a compression test. Any ideas? I can't rally do any intensive diag on it till next weekend...but it almost sees like I lost a valve. So far I basically just checked over the work I did...fuel filter isn't leaking, all fluids good, belt and tension are good.

Will I see anything by pulling off the valve cover? Anything else I can do tonight? Any possibilities?

Thanks...I'm hoping I just need to tp up my blinker fluid or somethin...

Joe S 04-17-2011 07:35 PM

Re: URGENT: Old Nuc I need help!
So I changed my mind...I'm not checkin anything today.I'm tire and freezing...I'm just going to deal with the car later. Feel free to point me in a direction though :)

PlasticCarsRock 04-17-2011 09:04 PM

Re: URGENT: Old Nuc I need help!
The fact that this happened immediately after an issue with the throttle sticking open could be a bit more than a coincidence. Is there any way that a piece of plastic or anything else could have ended up in your air intake? If something were to get in there (piece of plastic broken off from the air intake, screw, etc) it could have become lodged in the throttle body until you "kicked" it, allowing it to go through until it got stuck in a valve. If it's just plastic, it will probably melt within a few seconds to a minute if you can keep the engine running. If it's metal, it might do some serious damage...

I had a similar issue a few months ago--aftermarket cone filter started disintegrating from the inside out (little pieces of plastic were breaking off). They hung up in the valves causing horrible misfires for 5-40 seconds until they went through (not only do you lose one cylinder, but the exhaust gas chokes the other cylinders if an intake valve hangs open). I didn't notice it until a whole section of the filter disappeared (after replacing two sets of coils, an ICM, spark plugs, wires, etc).

manualman 04-18-2011 12:00 PM

Re: URGENT: Old Nuc I need help!
You do know that only ONE aftermarket fuel filter is any good on these cars, right? I forget the #, but it's a Wix. Search for it.

Joe S 04-18-2011 01:21 PM

Re: URGENT: Old Nuc I need help!
The Napa filter is a Wix filter. I have already confirmed it.

OldNuc 04-18-2011 02:04 PM

Re: URGENT: Old Nuc I need help!
Fuel pressure. With the car off does the throttle operate smoothly? Stuck shut is common but stuck open is very unusual. I would suspect that a component has failed mechanically, such as TPS. I would be looking at the TB closely and attempting to cause the failure while engine is off. There is the possibility of lifter guides failing or becoming dislodged but that makes much noise also. When the throttle stuck did the engine hit the rev limiter?

TomM96 04-18-2011 05:28 PM

Re: URGENT: Old Nuc I need help!
a compression test will offer info on at least the current condition of cylinders&valves&gasket....

OldNuc 04-18-2011 06:42 PM

Re: URGENT: Old Nuc I need help!
+1^^True. I still think the problem is related to that stuck throttle.

Joe S 04-18-2011 07:39 PM

Re: URGENT: Old Nuc I need help!
So here's how today went...

Pulled engine code. 0301, cyl #1 misfire. Erased.

Pulled apart air intake plumbing and checked filter, to enusre nothing went through the filter or broke off anything. Looks goo.d Also inspected visible damge...looks pretty carboned up, but ok otherwise. Throttle plate moves as it should, no sticking or notching...

Pulled plug and inspected. #1 is super gasy and wet. Others check out.

Pull cam cover off, turn engine by hand to verify that the valves are operating smoothly. They all move as they should.

So reinstall cam cover, swap plugs and wires, to rule this out. Also unplugged MAP sensor for elimination. Car still misfires, throws 0300 code. Erased.

Remove cam cover and check chin tensin. Then checked timing. Pulled wire #1 to verify sparks :) No change in running condition when unplugged. Throws a 304 code...

Last thing...pulled injectors, all spray evenly.

So, to answer questions...
1) Throttle only stuckfor a moment. When I tapped it with my foot it came loose. Car never surged, rpm never jumped...I initially thought that it had gotten caught under the carpet. It was stuck as I had been holding it. It now operates smoothly.

2) No compression test today...tester was broe. However havin it done for me tomorrow...I asked for the numbers, but I am sre I will simply be given a "holds pressure" or "doesn't hold" for each cylinder...But getting out there to check this out myself is out of the question...

3) Lifters and valves seemed fine top side unusual amount of play.

4) While missing, it makes an awful racket. Much gas makes it's way through the exhaust system.

At this point my money is on valve problem...yar. Should I still inspect fuel pressure or TPS? I would have to purchase a tester, and don't really wanna spend al that money on one haha. I will make my way back out there this weekend...I expect a compression test fail.

Failure means I will pull the head...if it is just valves, I'll swap em out as long as there is no catastrophic damage to the head. If it's lower end stuff I am just going to call it quits on it...don't feel like pullin motors. I'd rather spend $500 on aother car and swap parts over...easier than $400 for a motor and swapping that...

Thanks guys

OldNuc 04-18-2011 08:26 PM

Re: URGENT: Old Nuc I need help!
OK, check compression the problem is mechanical. Possible collapsed lifter or cam follower roller failure. I would pull the rocker shafts and all the follower/adjusters one at a time for a look before pulling the head. Sounds like the problem is in#1. The P304 will come up if you pull the wire off of #1 and are arcing it to the block to check spark.

You may want to have your head rebuilt as just a used head is going to need work also. When taking the chain off be sure to position the crank key at 3:00 before separating the chain from the cam and crank or you will have more valves to fix.

The rocker shafts have to be unbolted evenly or they break.

Joe S 04-18-2011 09:28 PM

Re: URGENT: Old Nuc I need help!
Lifter/Rocker problem...check that first, regardless of compression results? Is it as simple as unboltig or do I have to worry about those valve springs? I had just done an oil change and was running 5w20...too thin perhaps?

I guess if it is a valve problem I can't just throw a new valve in eh? If I take it for a rebuild I imagine that includes all parts and machining?

Joe S 04-18-2011 10:03 PM

Re: URGENT: Old Nuc I need help!
And I guess I should mentionthe type of I an describe it is a good solid knock. Not hollow sounding...

OldNuc 04-18-2011 10:23 PM

Re: URGENT: Old Nuc I need help!
5w-20 is too light. You may have nothing more than all the hydraulic adjusters collapsed. Unless you find something like 30psi in #1 I would check the valve gear. All you have to do is evenly unbolt each rocker shaft and lift it and the rockers off. then the 2 springs that hold the guide plates down lift off and then the guide plates. Don't mix up the part locations! Once those parts are of you cal pullout each roller follower and hydraulic adjuster. One at a time put them under clean oil and press the ends together and release and they will pump oil into them. If they will neither pump up with oil then they may have collapsed. The rockers will slide off the rocker shaft and he shaft should not have a grove in it where the rockers have been running as the rockers have needle bearings. The valve springs will not come off unless you remove the keepers and that takes a spring compressor. Your best bet is thin oil and collapsed lifters. When you remove the follower you can see the cam lobe, look for signs of scoring and metal loss on the cam and roller. You will need the torque specs for the rocker shaft bolts when you replace the shafts as the bolts will break easily The spec is 19ft-lb. Before disassembly note how the rocker arm fits on the lifter and valve. There is a notch on the lifter end of the rocker that fits over the end of the lifter.

Joe S 04-18-2011 10:28 PM

Re: URGENT: Old Nuc I need help!
Too light eh? Any chanceI can half ass this and swapot the oil to something heavier and run it? :) OK OK, I know...don't half ass this stuff...
Alright then, that deffinitely sounds ike a good place to start! I will be out a the car at some point this weekend, and will give said items a good lok over!

OldNuc 04-18-2011 11:45 PM

Re: URGENT: Old Nuc I need help!
Well, if there was mechanical lifter noise from the engine I would change the oil and filter to a 5w-30 and see what happened. Needs to be changed anyway no matter what.

manualman 04-20-2011 11:45 AM

Re: URGENT: Old Nuc I need help!
I went to hard knocks school looking for a SOHC valve train problem. Removing the rocker shafts is easy and straightforward, but when putting them back make SURE the lifter guide plate retaining clips don't intrude into the shaft seat cast into the head. After a few turns on the shaft bolts, you will split the head casting open where the shaft mounts! (Then cry or invent new words).

After busting my head casting, I bought a rebuilt mail order from J&C Enterprises (an Old Nuc find) for $24 shipped. Almost 10,000 miles on that new head so far (and 40 mpg highway to boot).

Joe S 04-20-2011 11:14 PM

Re: URGENT: Old Nuc I need help!
Compression test results: Cylinder 1, 0. Yup, looked through the plug hole and there is certainly a nasty looking hole in the piston.

Bye bye SC1. Scrapping our 96, sent an email to a few locals trying to sell the 01 as a parts car...otherwise I am stripping the new stuff off and scrapping that. I have no time for a motor swap...Scrap money should be enough to start on another car lol...time to see if tehre are any decent 2nd gens kickin around...

OldNuc 04-21-2011 08:56 PM

Re: URGENT: Old Nuc I need help!
The 98 with the digital odometer seems to be a vintage year. :D Burning a hole in the top of a piston is a bit tricky....

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