Hi!


My engine is not running as good and clean as it should. Misfires a little (or that's how I experience it anyway) at idle and doesn't rev as free as I think it should. I experience it a bit choked, though I'm novice to these engines. The engine is a 350TPI -89.



The engine is stock except for larger fuel injectors, left there from when the previous owner had the engine tuned a bit. The injectors are size 24# I think. Can this cause the bad running? What is the correct original injector size?


Thanks in advance!


//Per

 

24# injectors are fine on a 350. Whatever the issue is with your engine, it is not the size of your injectors.

 

Okay, thanks blacksunshine'91!


I recently had a leak at the inlet gasket, causing coolant and probably oil as well to pour both out of the engine and got sucked into the cylinders. Could this have caused problems? For example damage on lambda sensor or spark plugs?


Also, I just discovered that my air filters where quite dirty. I'll replace them and see. Do you think that a more free flowing air filter would make the engine run better, since the injectors are a bit up-sized?


Thanks again!
//Per

 

... sorry, realized it's called oxygen sensor (above) but I guess you know this

 

Unless the ECM has been programed for #24 injectors it will run rich.You need to know What was programed into the chip .

 

It should be programmed as stock setup. So this shoud be changed? A piggy back thing with a chip was included with the car from previous tuning. I guess, if yo know how, it easier and cheaper to re-program the ECM than changing the injectors? A set of injectors (21# right?) is about $600 in Sweden.

 

Steve Mack is correct. You need to burn a chip to run 24lb in a stock 5.7 set up otherwise you will not get optimal performance. Stock replacements for a 350 are 22lb injectors.
our 22lb bosch lll's are $165 for the set plus a 10% discount for being a tgo member.
Not sure what they would charge to reprogram the ecm in Sweden

 

Thanks southbay08! Okay, there was obviously a significant price difference between US and Sweden (which is often the case). I'll investigate the re-progamming possibilities and give it all some thinking through.

 

No worries. If we can help you in any way just let us know

 

According to the EFI Math app in my phone 24lb/hr injectors (eight of them) will support 297HP, so unless your engine is producing close to that they're a bit too much for a stock TPI 350.

 

i'm kinda curious about this....i have 24# injectors in my t/a and have a new 350 with an accel base manifold, slp long tube runners, crane 2032 cam, hooker shorty headers, no emissions (except o2), summit aluminum heads and a computer programmed for 24# injectors, and its not running right, smells like its running a little rich still, and it doesnt like starting from cold....i tried asking about some fuel questions but got hardly any response. gonna watch this one.

 

After some general fixes, including new spark plugs and air filter, the car actually runs better (same injectors). Will drive it some and see how it behaves after awhile and also watch my fuel consumption. Will be back with info!


Dheers,
Per

 

If you need I can burn you a new chip.

If you want to know how the car can handle the injectors hook up a scanner and check the BLM values and do a WOT run with a WBO2 hooked up to see the AFR value

/N.

 

Okay, thanks gta324. I think I understood some of the "short for's" -measuring mix ratio before or after the cat maybe? AFR might be air-fuel ratio but what is BLM?


//Per

 

Thought I'd also hear what you think of the color of my old sparkplugs. Any obvious sign to you?


//Per

 

BLM base line map IE the values in the tables you have now in the prom. AFR air fuel Ratio, WOT wide open Throttle, WBO2 wide band Oxygen sensor. Those five don't look that bad probably just a little worn. Recommend iridium plugs will not wear out ever.

 

Aha, thank you. A bit wiser every day!


Cheers
//Per