checking injectors /edit now with pics

[3.1LUMITIC]

whats the best way to check to see if i have a bad injector. my car is running at 2k rpm at idle and if i give it a little bit of gas it will rev to 3k and go no farther. if i give it more gas if will bog out to 1k or less and i can smell alot of gas. when in gear it wont go over 30 mph and accel.. very slow. After i warms up abit when driving it will jump up and down the rpms till 2k then after that it goes like wildfire but only at WOT. ive rplaced most everything that would make it run like this besides my injectors

Replaced

tps

iac

all coils

icm

map

egr

pcv

fpr

thats about it anyother things i should try befor getting new injectrors?

it a 90 3.1mpfi bwt

 

-Matt

[DaveFromColorado]

I'd guess one of those injectors is leaking for sure ... I'd check your fuel pressure now and see what it's doing tho.

 

--Dave.

[Pontiac6KSTEAWD]

You would have to take off the upper intake manifold, and with a volt meter set on the pie setting, you pull the plug off each injector carefully (they have a snap collar and can be dificult to get off), you then jump the terminals. I see you have a 3.1, so you are looking for about 12.0 resistance or higher. anything lower is a bad injector. But this doesnt sound like a bad injector to me. But i could be wrong, and it wont hurt to check. I dont see anything about a fuel filter, a clogged passive fuel return system. But as said, this is pretty easy to check. Good Luck...

 

Also, what dave said :withstupid:

[3.1LUMITIC]

oh yea i forgot about the fuel filter i just changed it about 2 weeks ago and air filter and oil change at the same time.

[Canada]

First off, is the SES light on...if so, what is the DTC?

 

It makes good power at WOT? Smell a lot of gas?

 

While we are shotgunning parts...............did you replace the O2 sensor?

[3.1LUMITIC]

no ses lights o2 is a lil over a year old and ive had this problem for the last few months with it running overly rich huge puffs a black smoke. it doesnt smoke anymore after i found out my fpr was shot. but its still running rich. idle likes to surge for abit then idles normal. when coming to a stop in gear it will die somtimes. But im going to replace my cps since i havnt done that yet and replace my o2 b/c it could have fauled out by now. I will also post some pics of my spark plugs to see what ya'll think of them.

[NeonKnight]

did you have your battery disconnected for a period of time?

 

reset your idle. i dont have the link for it... but someone will get it for you, i think it is in the FAQ section. do an IDLE RELEARN and see if that helps it out any. my used to do things similar to this...

[GnatGoSplat]

You can do a quick check of injectors without pulling the plenum.

You would check each bank, and using Ohm's law, you can calculate the average resistance of the injectors in that bank. If unusually low or high, then you know you need to pull the plenum to narrow it down.

 

BTW, on your multimeter, it's an Omega symbol, not pi.

[turby]

Have you considered it could be the ECM?

[3.1LUMITIC]

i replace my ecm with my moms out of her perfectly running 92 3.1 gp and still the same thing so that taakes the ecm outta the question.

[turby]

i replace my ecm with my moms out of her perfectly running 92 3.1 gp and still the same thing so that taakes the ecm outta the question.

 

Just checking.

[3.1LUMITIC]

and who said im not rich

sorry for the blur shitty camera

 

[3.1LUMITIC]

just pulled the back spark plugs and one of the clips inside the wire what had came off the wire and the back plugs are rich too. the have a slight white area around the tip where the metal end comes out of the porcilin. :?:

[Supreme Cutlass]

what plugs are those? stock? if it's the correct heat range then carbon deposits like that can come from

-a rich mixture-

clogged air filter

retarded timing

or very low compression

 

Edit; in other words, check those injectors!

[95oldsVan]

You really needed a scanner to see whats going on during the engine running.You need to see 02 counts,blm,injector pulse width and etc.Sometimes a bad O2 sensor can make you run real rich or a bad vacuum leak,but then again an scanner can help one make a educated guess which is the problem.

 

The injectors needs to be Ohm cold then hot and see if theres any out of spec injectors.However,your car seems to be dumping fuel to what it sees as a lean condition(o2 sensor tells it that,hence the black plugs)

 

I bought a snap on scanner used some years back and it saved me a ton of money at times because(along with a repair manual) I was able to use it to see wtf was going on in a MPFI engine I had problems with.I didnt get any codes but seen the blm numbers and iac which told me there was false air or a vacuum leak in the engine somewhere I could not hear.I found it and fixed the problem.

 

Dont keep throwing parts at the problem,get the car scanned during its running and driving and see if theres a problem with the injectors,02 counts and etc.Find out WHY its running rich and stumbles before just taking expensive guesses as to what may be wrong.