inconstant idle
 

i have a 355 with tpi map set-up i was having a problem with the stock injectors that was in there they where leaking and would kick out white smoke and run rich after it cleared out the cylinders. change them out with 40 lb to see if the problem was those old injectors it was but i didnt realize that one vacuum port wasnt pluged so it was running really good no white smoke good strong idle only problem it was idleing around 1500 or less. after i pluged the port up it runs really choppy and there is white smoke and the idle changes a lot. i know the spark plugs are all carboned up but i dont want to buy new ones to just get them all messed up again. is the problem the injectors dumping too much gas or is it the idle control valve or something else i dont know what else to do

Re: inconstant idle
 

maybe do i need to send in my stock injectors to get rebuilt or should i get new ones or do i just need a tune and new plugs

Re: inconstant idle
 

Well for starters you swapped out your stock fuel injectors for 40 lb injectors? If thats the case that right there will cause you all kinds of grief as that way bigger than the factory ones. Next white smoke is usually a sign of water/antifreeze being run through the motor so first ide double check to make sure its really white.

Re: inconstant idle
 

well i know for sure its not any kind of water it was doing this with the other injectors too its running really really rich with the stock injectors and it runs better with the 40lb in there. i changed the injectors to see if the stock injectors where bad and they are leaking while the engine is off and i think while the engine is on

Re: inconstant idle
 

Well if the stock injectors were bad it may run better with the 40 lb injectors but it will never run good. What I would start with is change back to factory injectors weather there new or remaned that's up to you but the bottom line is it will never run right like that. I'm not saying that's your only problem but definitely a place to start and something that should be corrected before further troubleshooting is done.

Re: inconstant idle
 

Yeah, installing 40# injectors without recalibrating the ECM is only going to give you tons of grief. This is because you are now injecting almost double (180%) the fuel that the ECM thinks it is. You will be running as rich as Bill Gates.

Until you put in some properly sized injectors (22 or 24# only), or have your ECM reprogrammed to compensate for the 40# ones, it will be hard to isolate any other real issues that you may have.

Re: inconstant idle
 

but the thing is that it runs almost better then it did with the stock injectors

Re: inconstant idle
 

i am talking with a company that cleans injectors so we will see what they can do.

Re: inconstant idle
 

your making yourself sound a little ignorant here buddy.

listen to the above posters. your injecting about double the fuel your suppose to be injecting if using 40lb hour injectors.

it ran decent with your vaccumm line disconnected because of just that..... you had the vaccumm hose unhooked. that will cause the engine to run lean........ so maybe you somehow got lucky and about ended up compensating for your massively rich fuel condition by creating that size of a vaccumm leak quite possible...............

either way you are just wasting your time sending injectors out to be cleaned if you expect them to run well afterwords..........

Re: inconstant idle
 

The only possible reason that it would run richer with the stock injectors than the 40's is if one of the injectors was stuck open, which is a real possibility. However, continuing to use the 40's is only going to continue to make your engine run rich. Reprogramming the ECM or installing smaller injectors is the only way to clear it up.

Re: inconstant idle
 

40# injectors are way too big for a 5.7 (assuming that 40# rating is at 43PSI). Consequently, your engine will run way too rich when in open loop with a stock PROM and stock fuel pressure. It likely won't be able to compensate even in closed loop. You could burn a new PROM for your ECM to compensate as well, but that's still asking allot from those injectors at idle as the pulse widths would be fairly narrow.

I replaced my stock injectors with some 22# Bosch type III remans. It's a whole new car now.

Re: inconstant idle
 

ok i see that its to much gas yes but i need to put something in there so nothing got in the engine. but would cleaning the stock injectors fix the running rich problem or do i need to buy new stock injectors

Re: inconstant idle
 

Well assuming for a moment that the injectors were the cause of your original running rich problem cleaning may or may not help depending on what about the injector actually failed. That being said personally I'de just get new injectors and be done with it because those injectors are probably original and probably not worth the investment of having them cleaned even if it worked for now as eventually they will fail again and you will need to tear things apart again spend even more money now more headachs more aggravation of troubleshooting. To me its just not worth it in the long run especially concidering the injector cleaning isnt guarented to fix your problem in the first place so you may put it all back together test it and have to tear it apart again if it dosnt work. Honestly I wouldnt hold out to much hope that an injector cleaining would solv your problem. However thats my oppinion on matters at the end of the day its your car and your money to do with as you see fit.

Re: inconstant idle
 

that is a very good didnt think of that but i hate having to drop 200 and new ones like if i could find out what injecotor is broken and replace it that would be cool but then it might end up that they all might fail anyways. by the way the stock injectors are not original to the car i bought these from someone else so i have no idea what condition they are in other then they where working fine before i did the rebuild

Re: inconstant idle
 

also how can you tell the size of the injectors i just want to make sure what i am running

Re: inconstant idle
 

i was looking at injectors and found 2 kinds that i could get. i was looking at the ford 19lb injectors for $260 or i can get the stock replacement from GM for $101 bucks.

Re: inconstant idle
 

I'd go with the GM's and save $160.