06blackGTO

iTrader: (20)

Okay Ridalin version: Just picked up my ol' 93 ta. after selling it 2 yrs. ago.

Car studders during low/mid rpm's. and it wants to die sometimes when coming up to a stop. Prev. owner said it started after he had another steering column put in.

so far. new plugs,coil,ign. switch.
wires are taylor full metal jackets. 1yr. old. msd opti, 1yr. old.
plug wires still seem to be in great shape. did a compression check today.
cyl. 1- 160psi. 2-160psi.
3-180psi. 4-175psi.
5-170psi. 6-170psi.
7-160psi. 8-160psi.

I took a temp. reading w/my temp. gun.

cyl. 1-350 at base of header. about 100-150 degrees lower then the rest.
cyl. 3-450-480.
5-500 degrees.
7-500degrees.

2-500+
4-500+
6-500+
8-500+ on ceramic longtubes.

so cylinder 1 is running cooler. could it be the opti? injector? plugwire?
when I pulled off the 1 wire the temp dropped to 250 degrees. put it back on and it climbed up to 350 degrees. still over 100degrees lower.
could that be causing my studdering and any ideas on what could cause it?
would a opti cause one cylinder to missfire? Im at a loss. but it does feel like it's electrical and not fuel, but I could be wrong. Plugs are ngk tr55's. and only a few days old. Pleas enlighten me. thanks...

Black96transam

injector might be dirty..try switching 1 and 2 over and then try it.. if it changes there is ya problem

06blackGTO

iTrader: (20)

Thanks... that's what a person said on another website also. I will try that. and if that's not it, I will switch plugwires and if that doesn't fix it then it might be the 1yr. old opti.

the injectors are accel 30lb'ers. about 3 yrs. old. Hopefully it's either the wire or the injector.

Wicked94Z

iTrader: (26)

fouled plug?

06blackGTO

iTrader: (20)

Update. Well I swapped the plug wire with the other side. no difference.
then I swapped the injector w/another one. no difference. it still runs 100-150 degrees cooler on cylinder 1. The plugs are only 5 days old. Any other ideas?
Im at a total loss. I put a stethoscope on the injector and it is clicking like the other injectors.I guess it could be the 1yr. old msd opti. but I hope not.
I did notice that the crane gold rockers are rubbing against the nuts.I was told by the head shop that ported these heads that they have not been milled, and to run stock pushrods.I have comp hardened stock length pr's in them, but it looks like I need to get a pr length checker and find out what size I really need. I don't want to chew up these high dollar rockers anymore.
If someone has any other idea I would really appreciate it. thanks.



Oh yea car is still studdering.

Black96transam

now i'm leaning towards opti.. take off the dist. cap and check the points.. take a piece of sand paper and scuff all the point and the rotor button.. make it "shiney" then try it...

06blackGTO

iTrader: (20)

Well I'm going to try one more thing befor the opti. I'm going to do a leakdown test on that cylinder
Tomorrow. And see if the intake or exhaust has air blowing out. It read 160psi. On the compression
Test. And cylinder num. 3 next to it read 180psi. I figured I would try that before tearing into the opti.

06blackGTO

iTrader: (20)

Okay I found the problem tonight. The exhaust valve on the number one cylinder is leaking. 1st. compression check. this time 175 compared to 160 last time. and in the span of 1 min. or so I watched it drop to 160psi.

then I put on the air hose. it would not build over 75psi. connected to the cylinder. I opened the t.b. and could not hear air leaking. put in my stethoscope in the tail pipe and I could hear air leaking. then I took off the air comp. hose while air was still in the cylinder and held my finger over the end of the hose. after about 20sec. all the air leaked out of it.

so I'll be pulling the head on wed. and putting in a new intake and exhaust valve on the 1 cylinder. then I'll go from there. plus I pulled out the plug and it's a week old. looks like it hasn't been firing at all. the plug still looks new. no discoloration at all...

Hawk40

wouldnt the exhaust valve need to be leaking a LOT to cause a noticeable stumble? i mean even with lowered compression i wouldnt imagine it would be as noticeable as you're describing...i dunno...just thinking out loud

06blackGTO

iTrader: (20)

Well I have a auto xray scanner coming to find the stumble. Could be a bad 02.
But atleast I found the reason the cylinder was running cooler and was down on power.

creepingdeath94

iTrader: (1)

Also, was the engine warm when you leaked it down? Sometimes you get some leak down naturally if everything is cold. I just would hate to see you pull heads and valves if that was not the culprit. Also, try and smooth those chewed up spots on the rockers. Basically polish down the high spots/rough spots and get rid of any corners, edges, sharp spots, etc. as they tend to give the metal a place to fatigue and crack.

06blackGTO

iTrader: (20)

Well the engine was warmed up pretty good. and then I let it sit for about 30-45 min. w/a house fan on the driver side cooling down the headers. then I did all the checks. the plug is only about a week old. but doesn't seem to be firing at all. but the top, the metal that overhangs over the tip seems like it has been getting hot, like spark.The injector is clicking. and like i posted earlier I switched injector/plug wire and no change. I can switch the injector plug 1 with the 3. since this is a 93' and batch fire, I can do that. and see if it is the harness. I really would hate to have to pull the head and that not be the problem.It's either the valves or the inj. plug or the opti. I would just think that if a valve is burned, or bent that I would have crappy compression. but it was 160 the other day. and lastnight it was 175 on that side. so I don't know. I took some pics of the plug Im trying to load them in my computer now.

06blackGTO

iTrader: (20)

Okay pics of the plug. and it does smell like fuel.

Formula383

iTrader: (8)

Man, your problem sounds very similar to the issue I'm having right now. I have done just about every test I can think of over the past month and I came up with nothing. I took the car up to Waco yesterday to have it looked at.

https://ls1tech.com/forums/lt1-lt4-m...ggestions.html

I'll let you know what he finds. Keep us posted.

06blackGTO

iTrader: (20)

I'm starting to lean towards electrical now. I pulled the plugwire the other day. And it didn't change the way it idled.

creepingdeath94

iTrader: (1)

Sounding more and more like opti or ignition wiring issues. I wouldn't pull the head just yet :-p

06blackGTO

iTrader: (20)

Yep now I pulled the plug, and she has some color to her. like she is firing. I took a compression check again.. 175psi. and then the cylinder next to her and it was 175. did a leakdown test on both and they both are the same. so I would say the valves are good. I fixed the car wanting to die when you come to a stop. I took off the t.b. and cleaned it really good and took off the iac and cleaned it out also w/t.b. cleaner. and that solved that problem. I think I know why the cylinder is reading cooler. The electric fan kicks on quite abit, it was set up to come on quicker w/tune and 160 thermo. and the air is really blowing around by that 1st. header tube. so I took a reading on the back side of the #1 header tube, and it was 100 degree hotter then the front side w/the air hitting it. so I believe everything is allright w/cylinder #1. the car does have a low rpm stutter, but I have a scanner on the way and I'll get some readings. I might a a bad 02. because the fumes are really strong from the exhaust. even though I don't have cats. plus it's really going thru the fuel lately. so I'll wait to report what I find out w/the scanner. but I believe she's hitting on all 8 cylinders.

here are some eng. pics of the driverside. there is no intake tube blocking the fan from the headers now that I put on a ram air cai.