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Messages - Recap
76
« on: April 20 2012, 12:01:24 AM »
As the car ran for several years in it's current state I don't think the cam sensor could be 180 out. I do have a scanmaster so I can give so data. That was why I thought my airflow numbers were out as I was getting the data from that.
77
« on: April 19 2012, 04:33:01 PM »
Well the new MAF arrived yesterday and I bolted it on and was greatly disappointed as this does not seem to be the issue. Did drive it around a little just to see if it would magically get better! Not. So about to give up and see if I can find someone around here that can work on them. Any other suggestions before I give up?
78
« on: April 16 2012, 01:30:29 PM »
Cylinder pressures are a little lower, around 135 but that was on a cold motor. Only did 2 and 4 as I wanted to make sure 2 was ok after that I found. After doing a lot of pondering regarding why the rocker broke in the first place, I think I have a reasonable explanation. Rocker arms were contacting the splash shields slightly as there are small witness marks underneath the rocker where it contacted the splash shield. I think when I set the lash the rocker arm was resting on the splash shield as opposed to top of the valve. My guess is that I had lash on a hydraulic cam and finally beat the rocker arm into submission. The reason I say this is that the stock rocker arms have a lot less valve train noise than the roller rockers did. I will give the standard MAF and try and see how I get on. I think I can get this through Autozone locally. Wish me luck!
79
« on: April 15 2012, 07:37:11 PM »
Gas was changed out every year and stabilizer added. So I don't think it is a fuel issue. And the injectors have been removed and sent out to have them cleaned and flow checked. I think the issue with the dead cylinder was the broken rocker arm and bent pushrod. Neither valve was opening. I will check the ecm connection again, but did check them in past. No service engine light except when the key is first turned on before you start the car. Any idea what sort of air flow numbers I should see at higher rpms with no load. I can drive it if that would help, just runs real bad. If I do buy a new MAF, any suggestions as to where to get one or which ones to avoid as I know the remanufactured ones can be a bit hit or miss and really don't want to send the money on a translater at this point in time until I get the current issue sorted.
80
« on: April 15 2012, 03:27:20 PM »
That's correct, changed out the pushrods as the roller rockers took a different length pushrod. Just did a bit of checking on my ignition timing and all looks good. Put a 1.5" piece of tape on the balancer on the advance side and looked like everything was ok. Was looking at my scanmaster 2 and the airflow does not seem to change much when the car is revved up. Took it up to 3K and not much of a change from idle. Could I have a soft fault on my MAF as it is not setting any codes? Did the tap test on it a while back and again today and it does not stumble when you tap it. Unplugged it and the car ran pretty much the same with it unpugged! All the above has been done in park sitting in the garage. So no load on the engine. Runs too bad to think about driving it.
Also swapped in another chip of unknown comodity. Think the guy I bought the 40# injectors from gave it to me. Says 108 on it so am assuming it is a race gas chip. A different chip made no difference to how it ran. Thought it was a stretch, but had a bag full of them sitting around. Wish I could remember what they all were! The chip I am running is one Jay Carter made for me about 10 years ago. But any way, does not appear to be the culprit.
81
« on: April 15 2012, 01:57:16 PM »
Did get the broken rocker replaces some time ago and while I was that far into it, decided to fix the intake manifold gasket that has been leaking oil down the back for my block for years! So all back together, start it up and it still runs like crap. So as it was still cold out, I was in no great hurry to drive it as there was snow on the ground, and the fact that I was totally pissed off at it, I have not looked at if for several months. So back at it again this weekend in hope of being able to drive it some time! About a week away from dragging it in somewhere and saying "fix it". So to outline again what I have done as best as I can recall - New O2 Sensor
- Checked fuel pressure
- New sparkplugs X 2
- New Plug wires
- New Fuel Filter
- New Coil Pack
- New Ignition Module
- checked resistance between engine and battery to see if it was a grounding issue.
- Removed injectors and had them flushed and flow checked
- Compression check on all cylinders
- Checked injector harness with node light to make sure all injectors are pulsing
- Checked to make sure all plugs are firing.
- Replaced roller rockers with stock rockers as on #2 cylinder 1 rocker arm was broken and other valve had bent pushrod
- Checked cam position sensor, all good. Suspected maybe time chain was off for some unknown reason and thought this was the easiest way to check this.
- Rechecked compression on #2 and #4 cylinders.
Any suggestions any one? I am out of ideas. Thought I had this diagnosed when I found the broken rocker arm, but that was only part of the problem. Still runs like the timing is way off or it is not firing on a cylinder or 2. About the only things I have not replaced on the MAF and crank position sensor at this point.
82
« on: November 27 2011, 11:00:51 PM »
Drained the rad and removed the heater pipe so I could get the valve cover off and inspect damage. The rocker arm on cylinder 2 exhaust was the one that broke. The pushrod on intake 2 was bent so bad I had to pull it out with a pair of vise grips! As I am this far I think I will pull the intake off and make sure the lifters and cam are ok. The intake has been leaking from the back for years so I can kill 2 birds with one stone. I think cause of all of this is the splash shields on the valve springs. It looks like there is a clearance issue with the roller rockers and the bigger cam. I read in the GNTTYPE archives that .450 was as big as you can go without out having an issue. Need to check my cam card, but am pretty sure the lift is more. When the guy originally built the heads he did not put the splash shields on. He also installed PC seals on the intake valve and no seals on the exhaust. This made the car smoke like a fog machine at idle. So I re-installed the splash shields, which only marginally helped and the installed seals on the exhaust valves which ultimately solved the issue. So it looks like my fog fix caused the problem. I can see some minor marks on the underside of the other rocker arms, but it was barely enough to remove the blue anodize. Also better check all the other pushrods to make sure none of the others are bent. Will try and post some pictures of the damage tomorrow if I get a chance.
83
« on: November 21 2011, 11:42:40 PM »
Well I think I have figured out what is going on. Checked to see if all cylinders were firing with my new widget and to my surprise they all were. So started to pull off the passenger side valve cover. It's been 5 years so I forgot what a pain it is to remove. Any way, got all the bolts removed and tried to get it off. Forgot you need to remove the heater pipe running along the valve cover. As I was trying in to remove it with the heater pipe still installed I noticed a piece of blue anodized aluminum hiding in the from of the head! Looks like I had a rocker arm give up the ghost. Never would have guessed that one in a million years as the car has basically been siting for 5 years straight. So hopefully once I get the valve cover off I don't have too much of a mess. Thankfully I think T & D are just up the road from me about 15 miles. Thanks everyone for all the input. Will let you know the final out come once I get the valve cover off. My back had had enough for the night as I just got my 4 post lift assembled over the weekend and the GN was parked underneath it and the lift was just high enough to park the GN under it. Oh my aching back! Bad planning on my part.
84
« on: November 17 2011, 11:19:18 PM »
Does checking the EGR involve removing it? Have never had it off, so............
85
« on: November 17 2011, 04:31:37 PM »
I know you can ground the plug, but was warned by Red Armstrong about only firing one of the two paired cylinders as it can take out the module. So picked up one those gadgets that connects between the plug and plug wire with the internal light to test it with this weekend, hopefully. New 4 post lift arrived a week early while I was out of town so will be spending most of the weekend trying to put that together so I can get it off the drive. Will let you know what I find out.
I did check compression and all looked good. All cylinders were cold when the test was done as I was changing the plugs out at the time and thought I might as well check compression while I was at it. I am also planning to pull the valve cover and have a look at the valve train to see if there may be an issue there. Having said that, I can't see how this could be an issue from sitting but at least it will rule it out.
Thanks for the interest and the suggestions. Keep them coming! I will post the results as soon as I get the checks done.
86
« on: November 12 2011, 07:41:11 AM »
Replaced coil pack due to checking header temps and having a cold cylinder. When that did not work, I replaced the ignition module. When that did not fix the issue is when I pulled the injectors and sent them off to be checked and serviced. Tried to put the list in chronological order as to what I have done since trying to diagnose the problem. Regarding checking spark, have ordered a little tester to do just that, so have not done so yet.
87
« on: November 11 2011, 05:34:43 PM »
Hopefully someone on this forum can help me out. As stated in the subject, I have a sick GN. I have been trying to sort this out off and on for the last 2 months. Below is what I have done to date.
-replaced plugs (twice)
-checked full pressure
-replaced plug wires
-new O2 sensor
-new fuel filter
-checked resistance between engine and battery negative post
-checked exhaust manifold temps with infrared temp gun
-new Coil Pack (Accel)
-new ignition module (Standard LX338)
-checked compression and all within 5psi
-verified signal to injector 4 was present (node light)
-had injectors backflushed and flow checked (checked out OK when he received them)
-moved injector that came out of cylinder 4 to different cylinder, no. 4 still not firing
I am not sure where to go from here. Any and all suggestions welcome!
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