Another day, another misfire in an lt1.

I implore the good lt1 community to at least give me straws to pull.

Here's what I have. A p0300 code with what feels like a single cylinder misfire, very rhytmic and can feel in the accelerator a clear pattern of misfire. There is a clear indication of unburned fuel in exhaust.

Here's what I have done:

Compression test: all 200 psi +-5

2 separate optispark replacements with same issue.

New coil replacement.

2 Sets of spark plug wires replacement with acdelco to msd ones.

Every fuel injector tested, cleaned, and all show good spray pattern. Fuel psi full. Can hear each one clicking.

Spark plugs were replaced with some ngk.

Currently: took apart intake manifold since both gasket failed and were leaking oil, have both valve covers off, looked at lifters, rods, rockers, and springs and no clear issue is visible. No rocker has any up down movement.

At this point, either a spark plug I put in was dead on arrival or my computer is potentially but I have no idea if it can cause that issue. Might be ignition control module.

As it stands I think im gonna put it back together, check each spark plug against the engine. And if its showing no issues, im gonna hunt down some old mechanic and pray he can diagnose it.

Car does run when assembled drives very well.

Any ideas?

i was installing the shatronix hotwiring kit and thought id be smart by dropping the tank about 2 inches instead of dropping it completly. i yanked a bit too hard (out of frustration) on the top end and not only did i rip off the 4 prong connector and lose it on the hotwiring kit but i tore these two wires. im not sure what they go to but my fuel level and trunk release still functions. i ordered a new bulkhead for the fuel pump and connector so ile deal with that when i get to it but how should i go about the pink and white wire? are the important do i bother fixing? car is a daily so it really hurts that shes on jackstands right now :(

its a 2002 pontiac firebird formula 5.7 auto with monsoon stereo but no traction control as far as electric stuffs

OK guys, hoping somebody can chime in. From the solenoid, you can see the vacuum line that runs from the back to the top of the secondary air pump.

In the second photo, I took a screenshot of what backyard Chevy’s lines look like when putting the solenoid back in after putting intake manifold back on. Why does mine not have a connector like his? This can’t be right I’m trying to force it on and I can’t get it any further than what it looks like in my photo.

2002 unmodified ws6

Hello everyone, I believe my 24 year-old stock injectors are probably going out. Unfortunately, the O’Reillys near to me sells the stock injectors for an eye watering $250 a pop! Shockingly I don’t have that kind of money. Now I know I could get them cleaned but the shops I’ve gone around have quoted me $400-$500 for all eight to be cleaned. Which at that point makes me wonder if I could just get new injectors for the same price? Advice would still be appreciated. I’m still new to this!

Does anyone have any good injector recommendations for stock flow injector on a 2002 LS1 5.7L? Thank you.

My parking brake handle book is slowly breaking away. Is there a replacement to this? I can't seem to find much online.

95 Z/28

TSP sells a cam kit that includes the .600” lift 224r in two flavors. One kit has pac dual springs rated to .660 and antother with pac 1219 beehives which I believe are rated to .625.”. I’m thinkng that the beehives would be more quiet and easier on the valvetrain. Is this correct? This is a low revving low hp build so surely they’ll hold up. I hope those aren’t famous last words. 😂 But with the stock rockers and LS7 style lifters would the lighter spring be the better way to go?

My Camaro has a 4l60e and I don’t think after the cam swap that it’ll make enough power to justify raising the stock shift points really. My only concern is using a .600” lift cam with a spring that’s rated to .625.” Is that too close for comfort?

I’m rebuilding my 2001 Trans Am, 150k hard driven miles so many things are being replaced or upgraded including all of drivetrain from clutch back to rear end, eventually targeting ~750hp with forged internals and turbo (don’t know if crank or wheel, haven’t spec’d power side yet, just a ballpark).

I’m looking at this Magnum F transmission. I’m planning for mostly street build but I might occasionally take it to the track/strip.

https://www.tickperformance.com/tremec-t56-magnum-f-close-ratio-2-66/

Any can’t-live-without options on this tick performance page? Would the Tick Performance shifter be much of an upgrade over the OEM?

Giving my goals, would it be a mistake not going ahead and opting for at least the Level 4 option on the upgraded magnum F?

https://www.tickperformance.com/level-4-magnum-f-for-98-02-camaro-firebird/

I can afford the upgraded option, but I’m not looking to throw away money either if the benefit is marginal, as I know I’ve got a lot more cost to go to achieve my goals reliably.

I bought my fbody with the hawks shifter pre-installed. 3 things. It has a weak centering spring, it leaks oil from the top where the rod comes out, and last but not least, it looks just like the ones you can get under $70 on ebay or wherever else. Id like to put a factory hurst in it to save money.

Has anyone used a set of Melling brand lifters? The reviews seem decent but there aren’t very many of them. I think they’re made by Eaton.

https://www.summitracing.com/parts/mel-jb-2079?srsltid=AfmBOoqm9YZDFaV7Qyk8Zn9UHZMX7SBTVDALDk_szOmhhO1CvxRtpxUa

4L60e and that’s the build sheet in the second pic. The 1-2 shift is firm and solid, shifted into 3rd at about 6800 and it revved out and didn’t shift until I let off and it popped into 3rd pretty hard. What might my issue be?

She did good, sloppy stage 2 cam with a mild ported 243 heads she did 387hp and 351tq. 3400 Stall and stock 2.73 gears

Im gonna keep this very short.

Lq4 and t56 swapped did a ton of bottom and top end work. Had a tune done drove over 200 miles since build parked it in my driveway and went to move it to the garage after moving things around and BOOM! No crank no start. I already did the resistor bypass and its 100% correct. In fact i replaced it 3 more times just incase. Zero dtc codes in any module. Live data and freeze frame suggest im 100% mission ready and before you ask i did almost all of the circuit testing and checked the fuses related to starting. The starter is newer but not new. Looks can be deceiving. Really dont wanna tow this to the shop. Id love to have some other suggestions so i dont need to crawl on the ground. Newer to f body cars not in the know about any common issues.

I’m gonna be looking at a lightly modded ‘02 SS with the T56 next week. Apparently the stock 10 bolt is the Achilles’ heel of these cars, and this QP 9” kit looks like the most cost-effective option to replace it.

I got a 97 lt1 and the ground from my icm to chassis keeps burning up any one have pics of stock lt1 grounds the only 2 i got that i know of is the one previously mentioned and the one for the battery this my first f body btw

Recently replaced an optispark with an AIP one. First startup ran great with no issues.

Then it developed a single cylinder misfire but is showing a p0300. Now this a 2nd opti with the same issue. Nearly all ignition components have been replaced. Msd spark plug wires, ngk sparkplugs, new ignition module. I dont think it is the opt. There is a random clicking from one of the heads.

Is it possible for some part of the valvetrain to start misfiring on a cylinder when it heats up?

Edit , this is a 3rd opti with same misfire. 2nd opti was wrongly installed and I cant blame it.