TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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hey guys this has probably been beat to death but i cant find any threads on this......ive been noticing valve train noise, specifically lifter rattle at all rpms. this motor has 1000 miles on it and ive changed the oil 6 times already. im running straight 30w oil and after driving about 60 miles after every oil change it starts the lifter rattle thing. so today when i was changing my oil it i noticed the smell of gas in it and it was very thin. so now i know my lifters are rattling because of the thinning of oil. but my question is how gas is getting in the oil pan. could my new injectors be leaking off? i installed a new afpr so ive eliminated that. these are the new 24# accel injectors. could they be bad?.....this is a new motor guys so please help me with any advice you can.....thanks
__________________ 1988 gta 350 L-98...stock
1989 formula 350...383 stroker, edelbrock vortec rpm airgap intake, 670 street avenger,crane 1.5 r/r, zz-9 cam, p/p vortec head , msd-6a, c/e frame ties, hotchkiss tower brace, 3.73 richmond gears with auburn posi, everything fully blueprinted/balanced and gasket matched. 700r4 reworked with kevlar internals,2400 stahl
Do a full compression and leakdown test. Make sure no cylinder is less than 10% compression reading from either the highest or lowest reading cylinder. Leakdown should be 10% or less on a new motor. Even less if you used gapless rings.
When was the last time you changed your breather filter and EGR valve? This could also be contributing.
The injectors could also be dripping fuel. That would really suck, especially since they are new. You can always have them tested if you can find a place with an ASNU machine.
thanks guys for replying. im going to run a compression test but before i do im going to put my original L-98 injectors back in the car to try to eliminate the problem.they all checked out at 16.4 except for two of them and they are 15.4 and14.2. i havent got my chip made for it yet and that makes me wonder if the computer is responsible for this happening. my stock injectors are 18#s? and i went to the 24#s without any chip work being done. ill do the leakdown test on the cylinders after i change them out. i thought when you turn the key off the injectors closed, so how could they be leaking through? it has a new egr valve on it but sometimes it will throw a code 42 especially if the outside temp is under 30*???. thanks guys and keep the advice coming, i need all of it i can get. thanks
__________________ 1988 gta 350 L-98...stock
1989 formula 350...383 stroker, edelbrock vortec rpm airgap intake, 670 street avenger,crane 1.5 r/r, zz-9 cam, p/p vortec head , msd-6a, c/e frame ties, hotchkiss tower brace, 3.73 richmond gears with auburn posi, everything fully blueprinted/balanced and gasket matched. 700r4 reworked with kevlar internals,2400 stahl
You're overfueling the engine. You should have mentioned that from the beginning. I wouldn't even bother doing a leakdown now. There is just way too much fuel going into the engine. Get a chip made for the engine ASAP, and don't drive it with the 24s in it anymore. You're risking serious damage to the cylinder walls, bearings, rings, and valvetrain from insufficient lubrication.
Im definatley gonna have to disagree. Theres no way in hell, with his mods listed, that he can be over fueling the engine enough to do any damage. Even with the stock bin and 22lb/hr consanant, the 24's arent that much more, not to mention that his engine combo is most likley burning all of the fuel in there as it si. I ran 24's on a virtually stock L98 and stock chip, and never had any problems like that.
Like previously suggested, run a compression and leakdown test and post your results. I think your problem lies within improper ring gaps/seating. Also check your vacuum... It could be as simple as an improperly seated intake gasket dripping gas into the lifter valley. Kinda unlikley, but Ive seen stranger...
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Last edited by 88 WS6 TransAm GTA; 01-27-2004 at 06:14 PM.
Now we're both in dangerous territory. The injectors could be fine with the stock calibration or they could be the problem. Fuel pressure is a factor, as is the injectors rated pressure. Keep in mind that one company's 24s may be another company's 26s or 22s depending on the pressure at which they conduct their testing.
The bottom line is that you need a chip to properly take advantage of your combination.
You should probably do the compression/leakdown test anyway, just to be safe.
ok guys i just changed the accels out for my stock injectors and the difference is like night and day. i run a test on the accel injectors and they were definately leaking thru. as soon as i turned the car off the needle on my fuel pressure dropped 40#s in less than 1 minute. i installed the factory ones and they dropped 4#s and never went lower. the car idles better, and the throttle response and power is where i think it should be for my mods. i guess the accels are junk and im hopeing jegs will take them back since theyve been leaking off since new. i believe my fuel pump is weak because i cant get over 45#s of pressure thru my new holley afpr. but for once its finally running rich which it never had before. i hope it fixed my problem but i havent had the chance to do a compression test yet but ill get to it this week and post the results.....
__________________ 1988 gta 350 L-98...stock
1989 formula 350...383 stroker, edelbrock vortec rpm airgap intake, 670 street avenger,crane 1.5 r/r, zz-9 cam, p/p vortec head , msd-6a, c/e frame ties, hotchkiss tower brace, 3.73 richmond gears with auburn posi, everything fully blueprinted/balanced and gasket matched. 700r4 reworked with kevlar internals,2400 stahl
If you have an 89 engine in it are you running a map sensor? I have a 90 (map sensor) and I put a cam in and 24# SVO injectors, AFPR and some other things, when I got the car running it did the same thing. Besides fuel in the oil, it was fuel fouling my plugs, after countless oil changes and spark plugs while trying to figure out the problem I put my original injectors back in figuring this was my problem (since I was still running the stock chip). It was still just as bad, I , like you , could not find anything through my searches until I finally came across the post I was looking for. It was about map sensor vaccum lines and their length and diameter and the effects on the info sent to the computer, I had relocated my map sensor from the plenum to the firewall because my new fuel rail mounted fuel gauge was in the way. I had a longer, larger diameter vaccum line on it due to it's new location. I made a new bracket for it so I could put it back in it's original location with the original vaccum line, which was about 1/3 as long as the one I had on there and made of hard rubber. Problem solved !, this may not be what is wrong with yours, but I just figured I would throw out another possibillity. I know if I had found this info sooner, I would have saved about $100 between oil, filters and spark plugs, besides all of the aggrevation!
thanks for replying but im running the maf sensor. im just hopeing the accels were my problem. the factory injectors i put back in arent bleeding off. i just hope i havent damaged the motor any. ill know more after i run a compression test but ive got to say it feels stronger and smoother than ever before so maybe i caught it in time. i called summitt racing today and their taking the injectors back, and reimbursing the money into my account. so thumbs up to summitt and down to accell.
__________________ 1988 gta 350 L-98...stock
1989 formula 350...383 stroker, edelbrock vortec rpm airgap intake, 670 street avenger,crane 1.5 r/r, zz-9 cam, p/p vortec head , msd-6a, c/e frame ties, hotchkiss tower brace, 3.73 richmond gears with auburn posi, everything fully blueprinted/balanced and gasket matched. 700r4 reworked with kevlar internals,2400 stahl
p.s. i called jegs to ask for a refund and after arguing back and forth abut the injectors it dawned on me that i bought them from summitt racing i felt like an idiot. but anyways thumbs up to summitt........
__________________ 1988 gta 350 L-98...stock
1989 formula 350...383 stroker, edelbrock vortec rpm airgap intake, 670 street avenger,crane 1.5 r/r, zz-9 cam, p/p vortec head , msd-6a, c/e frame ties, hotchkiss tower brace, 3.73 richmond gears with auburn posi, everything fully blueprinted/balanced and gasket matched. 700r4 reworked with kevlar internals,2400 stahl