What are some signs of a leaky injector, other than the obvious of bad gas milage and wet plugs after cranking...

I think i may have a/some leaking injectors because my car has been gettin really bad gas milage (about 200km to a tank...ran on 91 octane) and sometimes it has an irratic idle...it idles at about 2000 rpm at start up and then drops to about 1500/1300 once warm. Other than that sometimes when i am crusing down the road i can hit the gas pedal and nothin happens...its like my car "bogs" out...

by the way i own a 86SE with a 2.8L V6 auto with about 182,000 km

I have changed the plugs, wires, ignition module, cap, rotor, i just had the timing checked and set and i had the TPS and the IAC checked and set also. I have also changed the fuel filter about 5000km ago.

i have changed many more parts but that is all i can think of for igniton parts...
anything will help!

thanks eh!
-Phil

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86 SE V6 under constuction
Please rate me if i am of any assistance, thank you...

[This message has been edited by Phil86SE (edited 02-20-2004).]

I had two leaking injectors on my 88 2.8 - the only obvious symptom was after the engine was warmed up. Anytime I turned it off and tried to restart hot after it sat for a few minutes to 1/2 hr. I would hafta crank it over a long time. It would finally start, and some black smoke would puff out the exhaust for a few seconds. Cold starts and idle were OK. First place to look for your high idle is vacuum leak. There are lotsa places for it to leak on a 2.8.

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Tim
Red 88 Formula Auto 2.8 100K+ Miles - Hypertech - No Cat - No EGR

Murphys Law - "Nothing is as easy as it looks, Everything takes longer than you expect, And if anything can go wrong - it will, At the worst possible moment!"

Check your oil. Gas will leak past the rings when the car is not running and it ends up in the oil pan. Pull the stick and take a wiff.

Bob

What about the EGR?The EGR tube end that attaches to the intake manifold has been known to build up carbon and some times completely cuts off air to the EGR on high mileage cars,but that should cause the check engine light to come on or come on intermitantly.Other possibilities are cloged air filter.The port on the inside base of the throttle body (use a good throttle body cleaner).Also as FrugalFiero says, look and listen for any vacume leaks.GM didn't have much problems with the fuel injectors,but Nissans did.When you changed the plugs did you remember to gap them?Pop the trunk at night and see if you can see any sparks jumping from the plug wires to the engine block.Also take a look at your cat at night (after a short drive) and see if it's glowing,your cat may be on it's way out.

[This message has been edited by James Bond 007 (edited 02-20-2004).]

quote Originally posted by James Bond 007: What about the EGR?The EGR tube end that attaches to the intake manifold has been known to build up carbon and some times completely cuts off air to the EGR on high mileage cars,but that should cause the check engine light to come on or come on intermitantly.Other possibilities are cloged air filter.The port on the inside base of the throttle body (use a good throttle body cleaner).Also as FrugalFiero says, look and listen for any vacume leaks.GM didn't have much problems with the fuel injectors,but Nissans did.When you changed the plugs did you remember to gap them?Pop the trunk at night and see if you can see any sparks jumping from the plug wires to the engine block.Also take a look at your cat at night (after a short drive) and see if it's glowing,your cat may be on it's way out.

I have a new EGR tube off of a camero...just waiting to be installed...i have cut the cat and replaced it will a glasspack, the plugs were gapped properly and checked again...the air filter is good...about 7 months ago i removed the thottle body completely and throughly cleaned it..I have checked for vacuum leaks but i am going to purchase a vacuum pump and check again...
and as for the sparks gapping...i have checked before but i will check agian tonight...

FrugalFiero my car has no problems starting...hot, cold, just run, or left for weeks it fires right up..
and Lounge Daddy I will go smell the dipstick right now!

thanks everyone!

-Phil

[This message has been edited by Phil86SE (edited 02-20-2004).]

Check fuel pressure at rail, key on, don't start, fuel pressure should be 36-42psi and hold it for 5-10 minutes. If it goes down pretty fast, that would indicate a leaking injector. You would have to do this with mechanical gauge and may have to remove shraeder valve depending on model.
If pressure holds per above, then could be cold start valve or possibly a ruptured/leaking diaphram in fuel pressure regulator, which would suck gas into vacumm lines......Paul

Hey Prince Paul, i will have the fuel pressure checked next week

thanks eh

-Phil

Hey Phil...how about this brrr COLD weather affecting your gas mileage? Its been pretty cold lately here in Michigan, I am sure its been the same but more in B.C. If you warm it up before driving that doesn't help mileage either. Also that sudden gulp of below zero air when you hit the gas may bog it? Just a thought....

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Tim
Red 88 Formula Auto 2.8 100K+ Miles - Hypertech - No Cat - No EGR

Murphys Law - "Nothing is as easy as it looks, Everything takes longer than you expect, And if anything can go wrong - it will, At the worst possible moment!"

quote Originally posted by FrugalFiero: Hey Phil...how about this brrr COLD weather affecting your gas mileage? Its been pretty cold lately here in Michigan, I am sure its been the same but more in B.C. If you warm it up before driving that doesn't help mileage either. Also that sudden gulp of below zero air when you hit the gas may bog it? Just a thought....

It has actually been pretty warm here lately...like today for example the sun is shining and it is about plus 5-10celcius or so

thanks for the thought though

-Phil

I have exactly the same problem and when I check the plugs all of them are "dry" except one that is soaked and smells (stinks) gas.

Now... not to steal Phils's thread...
What cars have injectors that are compatible with the original 2.8 engine? I've heard that any Pontiac V6 up to -94 should work and that some 5.0 Mustangs have some.
I know that stock size is 155cc/min or 15 lb/hr if I'm not totally missinformed and that 19 lb/hr should work as a replacement but this means noting to me since I don't know where to find them.
There are a few scrapyards over here that have V6 Transporters, V6 Camaros and V6 Firebirds but the owners doesn't know anything about the engines or the injectors so I have to know what cars I can grab some from.

Thanks!

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J. Larsson, Supporting Member

I replaced my original pintle type 2.8 injectors with the multec type from a 1989 3300 engine from a Buick Century. It runs fine with them. I am not sure of the flow rate, but its gotta be close to the 2.8, if not the same. I would think any injectors from the 3100 would work along with the 3300. The 3400 may work (someone here on this forum may know the 3400 flow rate) and I am pretty sure the 3800 injectors are a tad too much flow.

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Tim
Red 88 Formula Auto 2.8 100K+ Miles - Hypertech - No Cat - No EGR

Murphys Law - "Nothing is as easy as it looks, Everything takes longer than you expect, And if anything can go wrong - it will, At the worst possible moment!"

Wow, thanks for the info guys,
thats exactly what i needed since i was considering changing my injectors anyways

off to the wreckers soon!

thanks again

-Phil

Yupp! Thanks for the info! That was all I needed to know!

Today I went to the scrapyard... found a 2.8 Firebird and the guy told me to take the whole engine only charging me 20$ for the injectors.
The engine had about 20.000 miles on it when the car got rear-ended two months ago so the injectors should be fine. And as a freebe it had an accell coil and plug wires on it.
Tomorrow the "new" injectors are going into my Fiero!

Thanks!!

Hi Phil

Another thing that you can try is to find a shop with a Snap-On motor vac system (try Winn Automotive) and have your injectors cleaned before you go to all the trouble of pulling your plenum. This may clear up your problem. Also if you really want to pull them out I believe there is a fuel injection service place in Kelowna that can test and clean your injectors out of the vehicle. Let me know if you need the name and I will dig it up.

-Brian

Phil: What thermostat are you using? If you engine does not reach normal operating temperature the computer will keep the engine running rich using more fuel. Make sure you have a 195 thermostat. Also, why are you running 91 octane. The engine does should not need 91. Higher octane gas actually burns slower then 89 and will cause more deposits than 89. If it is because of engine knock then check your knock sensor for proper operation. It it is ok then you might consider a carbon depletion treatment like BG. Good luck.

Hey thanks everyone

Brian i will totally keep that in mind and i would love to meet you sometime considering we only live 25 min away from eachother...we will have to arrange something!

and BobMarshall I am running 91 because my car seems to idle smoother running on it. My car does not knock on 87 though...As for the thermostat i am running the stock one...i am not sure which one it is and im not sure the temp my car runs at yet...i haven't done the temp guage fix yet. I went out to do it 2 days ago but i noticed that the clip into the temp sending unit has melted over the years...so i was unable to remove it. but i will find a way! What is this Carbon Deplotment treatment you had mentioned? Where can i buy it or where can i get it done? is that the snap-on motor vac that Brian was talking about?

Thanks again everyone for the awsome posts!

-Phil

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86 SE V6 under constuction
Please rate me if i am of any assistance, thank you...

[This message has been edited by Phil86SE (edited 02-22-2004).]

a puddle of fuel underneath the car.

quote Originally posted by Howard_Sacks: a puddle of fuel underneath the car.

There is no puddle of fuel under the car...

-Phil

quote Originally posted by Intel: Now... not to steal Phils's thread... What cars have injectors that are compatible with the original 2.8 engine? I've heard that any Pontiac V6 up to -94 should work and that some 5.0 Mustangs have some. Thanks!

is that true about the mustang injectors too?
if so that would be a huge bonus for me as i know a guy who pretty well has a mustang used parts shop in his garage....
if that is true would someone please let me know!

thanks eh
-Phil

quote Originally posted by Phil86SE: is that true about the mustang injectors too? if so that would be a huge bonus for me as i know a guy who pretty well has a mustang used parts shop in his garage.... if that is true would someone please let me know! thanks eh -Phil

I am fairly sure 5.0 injectors (not sure about what years) will physically fit, but I would think the flow rate would be a bit too high for a stock 2.8.

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Tim
Red 88 Formula Auto 2.8 100K+ Miles - Hypertech - No Cat - No EGR

Murphys Law - "Nothing is as easy as it looks, Everything takes longer than you expect, And if anything can go wrong - it will, At the worst possible moment!"

quote Originally posted by FrugalFiero: I am fairly sure 5.0 injectors (not sure about what years) will physically fit, but I would think the flow rate would be a bit too high for a stock 2.8.

What if you had a mild cam upgrade and higer flowing exhaust?

thanks eh
-Phil

quote Originally posted by Phil86SE: What if you had a mild cam upgrade and higer flowing exhaust? thanks eh -Phil

Well...I guess there is one way to find out for sure...if you can get those mustang injectors cheap/free, put em in and see how she runs! I still think they will flow a bit too much...maybe someone else on the forum will chime in on this...

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Tim
Red 88 Formula Auto 2.8 100K+ Miles - Hypertech - No Cat - No EGR

Murphys Law - "Nothing is as easy as it looks, Everything takes longer than you expect, And if anything can go wrong - it will, At the worst possible moment!"

I think i might have too

thanks everyone!

-Phil

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86 SE V6 under constuction
Please rate me if i am of any assistance, thank you...

Hey everyone, one more little question. What all is involved with changing the injector...how do you get them out and things like that.

thanks

-Phil

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86 SE V6 under constuction
Please rate me if i am of any assistance, thank you...

Today i pulled the plugs and they were all good, no smell of gas....only one had alittle "tinge" of oil on it and other than that they all looked well

one thing down, 200 more to check!

-Phil

quote Originally posted by Phil86SE: Hey everyone, one more little question. What all is involved with changing the injector...how do you get them out and things like that. thanks -Phil

You need to pull the upper intake and then the fuel rails.... you'll need new upper intake gaskets and EGR gasket if I remember correctly.

You'll need a 12 point socket ( 10mm if I remember correctly) for those purty intake bolts and to remove the brackets holding MAP etc.

Basically mark everything and clean up all the crud BEFORE actually pulling the injector rail up... you don't want the dirt creating a vacuum leak or getting into the engine.

You will also need a couple of picks or little screwdrivers to get the clips off ( they have to spread out a wee bit) the injector connectors, don't lose them and put the clips back in place before reinstalling the connector on the new injectors. They were made to go together... not come apart, so once you have the dang metal wire clips back in place correctly the connectors just push on the injectors and lock in place.

Hope this helps

[This message has been edited by Scott-Wa (edited 02-29-2004).]

quote Originally posted by James Bond 007: What about the EGR?The EGR tube end that attaches to the intake manifold has been known to build up carbon and some times completely cuts off air to the EGR on high mileage cars,but that should cause the check engine light to come on or come on intermitantly.

I thought the SES light would come on only if the EGR valve wasn't seeing control vacuum from the solenoid.

Either way, fwiw, one way to check about a blocked EGR tube is to start the engine, then press up on the EGR diaphram (from underneath, inside one of those lil holes).. if the engine stumbles and dies, your tube is not clogged.

Nathan

quote Originally posted by DCsoundNut: Either way, fwiw, one way to check about a blocked EGR tube is to start the engine, then press up on the EGR diaphram (from underneath, inside one of those lil holes).. if the engine stumbles and dies, your tube is not clogged. Nathan

how do you push up on one of those little holes without destroying the diaphram though?
thanks eh
-Phil

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86 SE V6 under constuction
Please rate me if i am of any assistance, thank you...

The regular EGR valve has large triangular cutouts on the underside of the hat, large enough to push your fingers up into and move the diaphragm. Some aftermarket types have a solid basket with little holes, those you can use a dull item like a pin punch and aim toward the center of the valve where the metal plate is.

JazzMan

quote Originally posted by JazzMan: The regular EGR valve has large triangular cutouts on the underside of the hat, large enough to push your fingers up into and move the diaphragm. Some aftermarket types have a solid basket with little holes, those you can use a dull item like a pin punch and aim toward the center of the valve where the metal plate is. JazzMan

I'm guessing i have an aftermarket one already but thank you i will have to go try that today!

-Phil