judging by some of symptoms my cars showing me, i think its time for new injectors. should i go with the stock accel 15's or get the 17 pound injectors, i plan on doing cam and lifters, headers, and some other small stuff in the near future, what should i do?

 

anyone???????????????????? also what kind of work would i have to expect in order to replace them myself...

 

Be patient. Dale will probably answer all your questions when he jumps in here. I know he has done a lot of tinkering with different injector sizes on his sixes.

Replacing the injectors yourself isn't that bad on the 2.8 or 3.1 engines - I did it for the first time a couple months ago and did'nt blow anything up. What I did do was go the the local U-pull-it JY and removed the injectors from a 3.1 so i'd know what I was getting into.

 

I was in exactly same situation as urs,
my injector is 190k mile old,
so I thought its time for a new one,
but I do want to mod my 3.1 v6 a little more in the future, although not too extreme(like NOS or supercharger).

but since summit racing description shows that when u move to 17 or higher, u need to set something up or tune something up with ur ECM, which I wasn't sure so
I just went with the 15lbs.

it arrived today, and I'll work on it in couple days when
I finish couple other stuff first..

I do want some tip too on how to do it,
do I need the lower intake plenum off? or just the
top one? and how much of a gasoline spill should I expect too..

 

ive only got 72k on my car, but, it seems like my injectors have issues...i do plan on a 50-75 shot of nitrous, so im not sure what to do, someone on here put in 17's without tuning and said it was ok...i dunno, let me know how it works out for you and what to look for...

 

anyone who has done the 3.4 swap uses the 3.4 injectors and has no problems. the common thought on injector upgrades is, leave them be unless you have enough air intake upgrades to need bigger injectors. if youre doing the basic bolt ons, you do not need bigger injectors, they will not give you more power, theyll just make you run richer, and eventually throw an o2 code. if youre going for more power, dont start w/ fuel, its air you need to start with.

as far as installing injectors, remove upper plenum, remove wire harness connecting to injectors and any other sensors on harness, remove bolts for fuel rail, gently and carefully remove ruel rail w/ injectors, do what you need to w/ injectors, repeat procedure in reverse order. thats the tall and skinny of it.

 

sounds simple enough, thanks drdave.
Im gonna tackle installing my accel 15lb injector
maybe this weekend, wish me luck

 

im going to order the 15's too, sogabe, let me know how it works out for you, pics would be great at critical parts too, thanks...
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def. seems easy enough as said above...

 

As stated the replacement of injectors is pretty straight forward. Just a couple of things to watch for -

1. The hardest part of the job (for me anyway) was getting the electrical connectors off of the injector. Glad I practiced at the JY first. There is a metal clip about the width of a small paper clip that holds the connector in place. After prying this clip out with a screw driver and watching it fly across the engine bay, I figured out that if you push in on the clip with your thumb while pulling on the connector is the correct way.

2. The Haynes manual says to drain the radiator and disconnect the throttle body coolant hoses. YOU DON'T NEED TO DO THIS. Just unbolt the throttle body and let it hang.

3. Get new gaskets for the upper intake plenum and throttle body. They've been compressed on there for 15+ years and could leak if you tried to reuse them. Make sure the parts store does'nt give you the wrong plenum gasket - their computer will pull up a gasket set that is for a FWD 3.1 with two different length gaskets. You may have to buy a complete gasket set to get what you need.

 

8492bird, you dont pry the clips out, you push them in and just pull the connector off. its like a lock button, just push and it comes right off.

 

I know that now. That's why I went to the JY first.

 

how long should this take a newbie? about 2-3 hours?

 

Took me right at 2 hours as a "newbie" but that included "refreshment" breaks. I asked a similar question when I first did mine and got answers anywhere from 30 min to 2 hours. I think for a first timer allowing 2-3 hours will give you plenty of time. Good Luck.

 

cool, yesterday I did open up my plenum just to browse around
and see how everything's hooked up and stuff.(since I had no time thats all I did)
but yeah I did see a clip, and I kinda tried to pry it off but
it was kinda hard so I let it go.. but
I know what to do now with it, great thanks to that!!

now as to release fuel pressure so that I don't soak my hand with gasoline,
is taking the gas tank cap off enough? or should I do more about it?

and why would I need throttle body off.. just wondering
is it just to make sure u dont get hurt?

 

You need the throttle body off to remove the upper intake. This is easier than removing the little hoses, and draining the coolant. But if your hoses are original, you may want to replace them anyway, all the movement may finish them off.

To release the pressure the right way, you need a pressure gauge with a release valve. Not having that, you can crack the fuel lines, and let the pressure release that way. Depressing the valve that looks like a tire valve, (schrader valve?) could result in an unwanted dousing. You will need new O-rings for the fuel lines.

Release the gas cap, any residual pressure will keep pushing gas out your open line. The fuel rail actually comes off easy, just rock it a few times, it kind of rolls out. Clean around all the holes, and OIL THEM. Stick one side in, then line up the other side with your fingers, and push down, you're done!!

OH, removing the injectors from the rail, there is a clip that retains them, just pull it out, the injector slides out. Be sure to replace the O-rings there, too.

Just curious, why do you think you need injectors?

Hope this helps,

Bob
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What symptoms make you think you need injectors? Just curious.......

Bob

 

thanks tealRS,
yaeh I forgot the tb attaches to upper plenum.. dumb me.

anyways if I donno where the pressure relieve valve is,
you're saying that opening the tank cap is enough to release the pressure right?

as for me replacing injectors,
I have hard time starting up the car(it takes a while),
my fuel pump is brand new(since it died on me last month),
and my engine starts faster when I have more gas in the tank, and the less I have in my tank the longer it takes to start.. and the shop told me it must be the injector, so
I hope they arent bull

 

The clip that holds the injector to the fuel rail needs to be rotated clockwise to release the injector from the rail. Do not try to pry or force the clip holding the injector to the rail - it will either bend or break and then you are SOL unless you have a JY nearby.

Your new injectors should have come with new O-rings - if not you can get them at any parts store.

 

Yep, 8492bird is right, those do rotate. I think the FWD just pulls off.

 

my car has a really rough idle, it hesitates like my grand prix did when she needed injectors, and sometimes it stalls for no apparent reason but fuel, but at the same time, i am hearing a whistle, around 3000 rpm, so i am thinking i have a vaccum leak somewhere maybe causing this. i dont want to put much $$ into the 2.8 as i plan on in the future most likely doing a carbed 350, th-400 swap...i was gunna mod the 2.8 but it seems aimless...

 

NO, opening the tank cap will not release the pressure, it will keep the fuel from continuing to flow after you remove the lines. There is a block bolted to the rail where the lines go in. On top of that, there is a valve that looks like a tire valve (it may have an aluminum cover on it). That is where you screw in your pressure gauge. If you do not have a pressure gauge, I would NOT recommend bleeding it off there, you may get an unwanted shower. Maybe cover it with a rag, but it's just as well to crack the fuel line loose at the block, and bleed it off that way.

How do you start your car? Try turning on the key first, and listen to the pump. It should stop after 2 seconds. Maybe turn the key off for 10 seconds and repeat, you'll notice the noise change as pressure builds up. You then have a full charge of fuel, and it should start faster. BTW, you DID change the filter, right? I'd check everything else before changing injectors, you know, the usual, plugs, wires, air filter, etc.

Hope this helps,

Bob
----------
Did you ever get rid of the hesitation in the Grand Prix? Did you change injectors in that, and did it help?

I'm trying to solve a hesitation problem, that's why I'm asking. Since I turned up the fuel pressure to 70psi, mine is idling rough now, too. No, it didn't solve the hesitation either

 

Just an FYI: I wouldn't disconnect the fuel lines from the fuel block. Just lift the block up leaving them connected. Several people here have crossthreaded the fuel line fittings. The steel fititng wins over the aluminum block.

RBob.

 

Is there a gasket in there? I don't know where you would find another one. Wouldn't that also risk kinking the lines? I agree, the lines can be hard to line up.....

Bob

 

RBob is right about cross threading potential but its a lot easier to change the injectors with the fuel rail out of the car, sitting in the shade with a cold one. Leaving the lines connected at the junction block and disconnecting them at the flexible hose connections on my 3.1 worked well for me.

 

the way i always depresurized my fuel system was to start the car and go to the back of the car. underneath the car above the rear axle and in front of the gas tank should be a connector. while the car is running you can unplug it . doing this unplugs the fuel pump and lets the car run on whatever pressure is still there until it dies. after it dies your depressurized.

 

Oh, you mean leave everything connected, and remove everything in one piece, lines and all. Could work, I guess, but there is a pulse damper bolted to the lower intake stud, and a wiring harness to unhook.

 

WOO, I did it!!
all 6 of them, no problem afterward!!

took me like 4hours caz every step I took,
i was scared as **** to do something wrong..
so I took lot of observation on how each components work
etc etc..

but here's what I did to take fuel pressure out.
take the fuel pump fuse out, and try
to start the car. f'course it wont start,
but the pressure is relieved at this point(I cranked it couple more time just incased)

now as for after the upper plenum off,
I labeled each harness with number so I wont get it mixed up later(might not even matter though).
and i pushed in some rolled up paper and stick it up on
each plenum's hole,
just incased some bolt or nuts fall in there then Ill have to remove the whole manifold or something..(which Im not too confident with, yet)

removed the wire clippy thing using flat head screwdriver,
and kinda twisting them off.(just careful not to let this tiny retainer clip fly around.. u might lose them easily)
then the connector comes off freely.

after removing some bolts off, I could tell the whole fuel rail was moving sideways a bit,
so I assumed that I could just force them out now.
I bent the fuel inlet line upward a little
so it's out of the way, and slolwly removed the fuel rail.
(the manual says not to remove the fuel pressure regulator out of the fuel rail)

after that, just roll the retainer clip,
then with some resistance injector will snap off..
use some engine oil to lubricate each end's o-ring,
then just do reverse for installation..


make sure when fuel rail is back each injector is
tight into the buttom hole.. then just bolt everything back.

i disconnected the battery just incased too,
and I had some spillage of fuel when removing fuel rail but not too much..
now my hard starting problem is gone, so good luck to you!!

 

sogabe,

Glad everything worked out, but the retainer clippy thing just pushes IN to remove the connector. You didn't have to remove them from the plug. So that solved the hard starting problem? Do you have any hesitation when you hit the gas? What injectors did you use again?

Bob

 

thanks bob.
I was too happy to state anything else..
but yeah to answer ur old question,
my fuel filter is pretty new, replaced maybe 3month ago.

now one day my car died on me, and the shop replaced the fuel pump for me.
since then the car runs fine but I had hard time starting the car, it would crank for up to like a whole minute to start sometime.
It tends to be worse when my fuel level is low,
so I called the shop saying that they did something wrong or they didnt do it right.

they took my car, and checked related harness and pump again, they said the pump is ok.
and that it might be my fuel injector.. so I took their word and bought accel fuel injector from summit.

it's a 15lb stock replacement one, direct fit
and my car doesnt crank forever till it start up anymore
----------
as for hesitation, I think its more like
slow acceleration.. but it could be caz my car's just slow..
it is an automatic and not much mod in the engine.. so yeah.
hopefully ill do a cheating mod(NOS) in the future though

 

sweet maybe if i ever stop workin 15 hour shifts at work ill get to this...still debating, work the 6, or 350 crate motor....i got a buddy who can hook me up with a ready to run 290 horse 326 torque crate motor, th 400 trans, and new driveshaft for under 3g's installed and ready to rock, what the hellllll should i do...

 

sounds like a good deal.
u want power, go for it bud,
but dont forget the gas price and v6's efficiency

 

I had the shop do my fuel pump, and after I got it back, the fuel gauge is weird. When the tank builds pressure, the gauge shows lower. I can fill it until its overflowing, and drive a few blocks, and it shows about 7/8 tank. It will never get all the way to empty, sits right above the empty line forever. It is a 15.5 gal tank, and the most I have put in is 13.8, cuz it shows that low for a loooong time.

Hesitation is a noticeable lag when you first step on the gas, a very severe lag can stall the engine. With an automatic, it would be less noticeable, because you just step on it once, and go. With a stick, every shift is a rocking experience!!

Glad your project was a success

 

drdave88:

I replaced my injectors about a year ago with supposedly "rebuilt" GM units from a place called Five-0 Motorsports. The original old injectors were definitely bad, running VERY rich, a few showed less than 8 ohms. It was so rich, the cat plugged up and caused many other problems. I did not record the numbers from the original ones.

I substituted a set from an 88 Grand Prix 2.8, and they worked fine, except for a hesitation when you first step on the gas (sag). Was told by a few sources that these would be too lean, and cause the sag. So I bought a set from Five-0, and have the same problem. The numbers on the injectors are: 5235136. Someone on here looked them up, and said they are 15.5pph units, and should work fine.

Do you think, dr, that going to 17s may richen it up enough to overcome this? It seems that no matter what I do, the computer wants to compensate for every attempt I make to enrichen the mix. I have increased the pressure to 70psi, and that seems to work until the computer figures out that it is rich, and leans it out. I have installed an MSD 6A with a Blaster coil, and still, after the computer learns, get lean misfire.

Any thoughts from you would be appreciated

Bob

 

from what youre describing, i dont think putting 17s in is gonna fix the problem. its just gonna be a band-aid. you might wanna check into making sure the ECM is working properly. how long ago was your last major tune up also? may wanna peek at your plugs and see how they look. check your cap for a crack or carbon tracking. you dont have any modifications done to your intake or fuel system do you? and how did you get the fuel pressure up to 70psi?

 

Yep, I was thinking that, too. Everything is new, ALL distributor parts, plugs,wires, TPS,MAP, IAC, EGR, AIR management valve, vapor canister(w/solenoid), purge valve (which is not hooked up to manifold vacuum, per underhood sticker), heads have been vacuum checked, new injectors, fuel filter. I have an MSD 6A with a Blaster2 coil. Have the updated PROM and a Stage 1 JET performance chip.

I got an adjustable FPR from Summit, which is just a cover with a screw, you use your existing regulator. Since the V6 has limited clearance, I set it to 65 with the manifold off, when I started it, it shows 70 (which is the pump max.)

No mods to intake, or fuel, other than the pressure, which was last week. I did take off the air cleaner housing, but the problem existed before that mod. Thinking about PROM burning......

Sorry 88CamaroSC, didn't mean to hijack your thread......

Bob

 

yeah whatever i am sure your sorry for being a thread hijacker....jesus!!!!! i HATE this.... ....naw kidding. its all good, i hope everything works out in a reasonable fashion for you....goodluck...

 

you have access to a scantool? if so, you may wanna hook it up and watch everything while youre driving it to see whats going on. see if something loses voltage or spikes or whatever may be going on. or have it checked because upgrading things is more than likely just gonna worsen the problem and the ECM is gonna keep trying to get it back to where it thinks is normal.

 

Well, I took it to a shop (last Oct.), and they replaced the PROM with the WRONG part. They used one for an automatic, so the shift light came on over 41MPH. But he did drive it with the scantool attached, and said everything checked out. The hesitation was actually almost gone, I could detect a very slight sag. Told the shop, and they vigorously denied any sag, said it had more power with the new chip (the wrong one), and they would disconnect my shift light if I wanted. I changed the timing chain a few weeks later, and when I re-hooked the battery...... it was back!! I then researched PROMs, got the right one, and here I am.

BTW the shop experience was a $400 education.
----------
You gonna work the 2.8?
------------
If you do, I'd be interested in hearing how it runs afterward, you say it is hesitating? You said in an earlier post that your GP hesitated, did new injectors fix that?

Changing injectors really isn't that hard, and it's good experience for ya!! Besides, it'll give you something to drive while you're dreaming about the 350.......

 

yeah it did fix the prob in the grand prix, but that car had 120k on it at the time, my maros only got 72k....dont know...

 

What I mean is when you first step on the gas at a stop sign, or light, is there a noticeable "sag" before it starts to move? It may seem to "jump", once it "grabs", or, if severe enough, can stall..... Do you notice anything like that?

Slow acceleration is one thing, but this is really annoying

Thanks,

 

when you did your timing chain, did you pull the distributor out? and are you absolutely positive timing is exact?

 

No, did not pull distributor. An interesting note, though: when I lined up the marks on the two sprockets, I put the damper on to check the timing mark, and, it was off!! The mark on the damper did not line up with 0o, I don't exactly remember now, but I think it was at 6o ATDC. I triple checked the alignment of the timing marks on the sprockets, and they were straight up and down. I used a security torx to loosen the indicator, and move it back. I had to move it all the way to the end of it's travel to get right, and even then, I don't think it was enough. I have heard stories of the rubber breaking loose and letting it slip, so I chalked it up to that. I did nothing to the timing when I first started it with the new timing chain, the hesitation returned, anyway, after that I started playing with it.

I did experiment with the timing, though, and the more retarded I ran it, the better the hesitation, but it ran hot and slow. I think I turned it back to 0o at one point, no power, but the hesitation was better.

You thinking timing is a factor?
----------
My maro has 170K on it. The GP I had had over 200K, neither one of them burns(ed) a drop of oil

 

neither do mine, but currently the gp has about 134k, moms driving it, as i bought a newer DD a year or so back...ive decided to keep the 2.8, so im going to order the injectors soon...

 

Good luck, it's really pretty simple. Hope it cures the problems