FuryZ28

So basically this is the story: I had an oil leak from the waterpump seal in the timing cover on my 93 Camaro Z28, so I pulled everything off, replaced the seal and installed a new waterpump geardrive. Put everything back together, and it wouldn't start, just popped and junk while cranking. Took it back apart and found the timing was off. I'm not sure how, seeing that I didn't move the cam or crank while the timing chain was off...anyways, set the timing properly, put everything back together, and it finally started but ran like crap, sounded like the car maight be missing or something. I checked my spark plug wires twice and had them all in the right order. I then bought new plugs and wires, and tried starting it again. Still ran like crap. I bought a Delteq (used) and installed it. Did the diagnostic testing and the optical sensor on the opti is working very well, however, after installing the system, it still runs rough. WTF is going wrong here???

JKDZ28

Coil? ICM?

FuryZ28

Did a coilpack test, everything works fine ignition-wise. My neighbor told me it sounded like bad plugs, even though I just replaced them! He told me the Bosch platinums (not the +4's) that I bought were crap, and that I need to get a better plug. Personally, I'd rather not hassle with changing the plugs again, only to STILL have a problem with the car running...

swemdog

i'm not familiar with the delteq, but it is possible to install the opti wrong, and it doesn't matter if you have the vented dowel pin drive, or the unvented shaft drive, they both can be put on wrong.
As far as your camshaft timing- Did you line up the dots when you put your chain back on, or go through a couple revolutions to make sure they lined up?

FuryZ28

I lined them up. I wasn't aware that it was any different than doing a full revolution...

Heatmaker

Your using the Bosch +4's?

I would change those out immediatly and put in some NGK TR55's.

While the Bosch may be good for other cars... they don't work well on the LT-1's.

I had ran the +4's... and it was like night and day compaired to the TR55's... the +4's worked... but they were lacking greatly. Try changing the plugs out.

ZMAN Z28

Just because you have fresh installed plugs, doesn't mean that you could have cracked the ceramic on a plug during the install. It has happenned to me before.

ZMAN

FuryZ28

When did I ever say that I used the +4's??? I put in the standard 1-electrode Bosch platinum plugs...about $2 a plug. I've ran Bosch's in the past w/o problems.

FuryZ28

Well, I had a more experienced car guy look at it, and figured it out pretty quick. Pulled off the valve covers and discovered the half of the CM pushrods were bent or broken. I'll be testing the valves tomorrow to make sure none of them are bent. It may be as cheap as some new pushrods, or it could be as expensive (and extensive) as needing the valves replaced and the heads reworked...

Heatmaker

yeah... I heard those suck too.

FuryZ28

Well, "HEARING" and "KNOWING" are very different from each other. If you noticed above, the Bosch's weren't to blame...

Heatmaker

It was just a suggestion....but that doesn't change the fact that Bosch still isn't a good plug manufacturer.

Good luck with the Pushrods.

MentalCaseOne

Talking about hearing and Knowing..... I have used the single and the Bosh 4 plats on my car. They ran like any other plug. Not better and not worse.

What I noticed is that after about 10k miles the center Plat insert showed signs of wear at the tip on both cases.


Also I tryed the TR55's and one of the plugs ceramic insert cracked in less than 1000 miles. Overnight. Making the car sputter and back fire. It was scary since I had the original opty with over 148k miles on the car still.

I did not crack the outside ceramic. It was the internal combustion ceramic that developed a hairline fracture. I am now using the TR5's since I have changed to Scorpion Roller Rockers and all the other stuff... About four weeks ago the car began to slightly missfire. When I first start it runs great... two or three seconds later if feels as if one or two cylinders go dead.... after it is fully warmed up its totally random... it runs smooth for a moment and missfires on the other moment. I have a brand new Opty. Less than 3k miles and my problem seem to be temperature related and sometimes it misfires when I give it gas but the Throttle position sensor runs smooth on the scanner. In Fact all the readable sensors look good on the scanner.



I am suspecting one or more lifters (brand new OEM) are pumping up (collapsed?) I re-adjusted the driver side lifters and my original adjusted settings had not changed, they seemed to be fine but I forgot to pull and check the pushrods for bends. I tested a new Coil OEM replacement and it wasnt it either.... I ran the car with and without the MSD ignition installed and there was not difference Whatsoever, as if the MSD was just simply passing the "one spark" over and not doing the multisparking. I did use a small spark tester over the coil hi voltage to opty wire and it did show some spark fluctuation at the same rate as the misfire. The spark tester is the kind that does not require to disconect anything and you just touch the outside of the wire and observe the sparking. It did the same with and without the MSD ignition conected but I rather see the sparks with a timing gun since the little tester is prone to pick up sparks from adjacent wires. I can not use it on the opti spark wire outs cause it picks up all the other wires signals. I will replace the coil as preventive maintanance since it has over 150k miles (original) and will replace the plugs with TR55's again. All the Fuel Injectors are firing (all are clicking) and the fuel presure is perfect.

At one point my coolant had ran low from leakage at one of the hoses and that has been fixed but it left me with the idea I may even have a blown head gasket from overheating..... I noticed the low coolant when I notice the in dash temp fluctuate at the same rate as the RPMs. The useless coolant lever sensor craped out on me years ago so its disconected... I am thinking I may have overheated without me knowing it and I am thinking blown head gasket but here is the kicker.... no coolant on the oil and it has a very small coolant leak at the Coolant lever sensor on the radiatior.... its so slow and you can faintly smell the hot coolant by the radiator that it may explain the slow coolant loss.... about a cup or two of coolant per week of driving. So I am not sure I have a blown head gasket or not. Again there are times when it just runs smooth after a full warm up. Other days it lopes more that a huge camshaft with a bad computer programing.

The MAF is good. I unplugged the sucker and the car ran the same with or without it. I did find a couple of tears on the rubber intake bellows right on the lip that connects to the Throttle and because their location I doubt they were leaking any air into the manifold. Besides the car runs the same with or without the MAF so thats not it. The Spark Plug wires are Taylors and were installed in December last year and I havent put over 3k miles on the car yet... I dont have Headers and by using a mirror I did not see and burnt wires nor any sparking lights in a peach black night around the engine.....

My suspicions are on any of or more than just a defective Ignition Module...blown head gasket...collapsed lifter (s) another cracked internal spark plug ceramic (as it did on me before)


I have replaced the oxygen sensors with OEMs so I doubt thats the problem there either.


Anyone has any suggestions? I still have the old Opty Spark that I replaced as preventive maintance and was running great after over 148k miles on it. I may even slap it back and see what happens.


Marvin

Heatmaker

I had ran the +4's... and it was like night and day compaired to the TR55's... the +4's worked... but they were lacking greatly.


I've used them as well for 20K miles...my car never worked well with them. There was a reason bosch discontinued them.

kevm14

I pulled perfectly good 20k mile +4s to install some TR55s. I detected ZERO difference.