Hesitation, staggering on acceleration and poor gas mileage.

[JoshBarber]

ugh, no progress yet.

I did try to pinch the return line off again, but this time when I looked at the rubber line I'd pinched off in the beginning, it doesnt really look like its a return line from the engine.....more like a loop from and to the tank. But its gotta be it, as its the only short bit of rubber tube there.

The guy working on the car hasnt pulled the upper cover to look at the regulator again yet. I think I'll tell him to do that with the key on now that the pressure is up, and see if he sees ANY signs of leakage. He said he didnt want to replace the regulator and have that NOT be the cause...and also brought up the common leak with the spider assbly in there. I'd assume he'd be able to locate the leak if it was one or the other with the cover off right? I can smell fuel (but cant tell where from) at times, and my gas mileage is at an all time low. Im talking easily single digits. I live 15 minutes from work, no traffic, and driving at approx 55-70mph, I can literally see the drop in gas by the time I've arrived. I'm hearing a slight pop in the exhaust when you goose the accelerator (like raw fuel is getting in the exhaust), and a small puff of smoke was seen this weekend on a single start up. It also surged more today......which seems to be consistant with the wet weather once again.

Chevy Dealer told me that it is possible for the fuel to be getting into the exhaust if one or both of these were leaking. I dont really know what else to do other than to take the top off, and replace the regulator. Its the cheapest fix. $90/regulator from Dealer, $60/from Autozone.

Anything setting off a light with you guys here? These symptoms point to anything? HELP?

[JoshBarber]

Originally Posted by JoshBarber

ugh, no progress yet.

I did try to pinch the return line off again, but this time when I looked at the rubber line I'd pinched off in the beginning, it doesnt really look like its a return line from the engine.....more like a loop from and to the tank. But its gotta be it, as its the only short bit of rubber tube there.

The guy working on the car hasnt pulled the upper cover to look at the regulator again yet. I think I'll tell him to do that with the key on now that the pressure is up, and see if he sees ANY signs of leakage. He said he didnt want to replace the regulator and have that NOT be the cause...and also brought up the common leak with the spider assbly in there. I'd assume he'd be able to locate the leak if it was one or the other with the cover off right? I can smell fuel (but cant tell where from) at times, and my gas mileage is at an all time low. Im talking easily single digits. I live 15 minutes from work, no traffic, and driving at approx 55-70mph, I can literally see the drop in gas by the time I've arrived. I'm hearing a slight pop in the exhaust when you goose the accelerator (like raw fuel is getting in the exhaust), and a small puff of smoke was seen this weekend on a single start up. It also surged more today......which seems to be consistant with the wet weather once again.

Chevy Dealer told me that it is possible for the fuel to be getting into the exhaust if one or both of these were leaking. I dont really know what else to do other than to take the top off, and replace the regulator. Its the cheapest fix. $90/regulator from Dealer, $60/from Autozone.

Anything setting off a light with you guys here? These symptoms point to anything? HELP?

Blazee/MT -

should I just go ahead and try with the regulator first here? If I do the pressure pinch test, its going to show an increase most likely whether its the regulator or spider assmbly. I can smell strong fuel inside the intake. I just wish I could rule one or the other out before I go and replace it.

[MT-2500]

Originally Posted by JoshBarber

ugh, no progress yet.

I did try to pinch the return line off again, but this time when I looked at the rubber line I'd pinched off in the beginning, it doesnt really look like its a return line from the engine.....more like a loop from and to the tank. But its gotta be it, as its the only short bit of rubber tube there.

The guy working on the car hasnt pulled the upper cover to look at the regulator again yet. I think I'll tell him to do that with the key on now that the pressure is up, and see if he sees ANY signs of leakage. He said he didnt want to replace the regulator and have that NOT be the cause...and also brought up the common leak with the spider assbly in there. I'd assume he'd be able to locate the leak if it was one or the other with the cover off right? I can smell fuel (but cant tell where from) at times, and my gas mileage is at an all time low. Im talking easily single digits. I live 15 minutes from work, no traffic, and driving at approx 55-70mph, I can literally see the drop in gas by the time I've arrived. I'm hearing a slight pop in the exhaust when you goose the accelerator (like raw fuel is getting in the exhaust), and a small puff of smoke was seen this weekend on a single start up. It also surged more today......which seems to be consistant with the wet weather once again.

Chevy Dealer told me that it is possible for the fuel to be getting into the exhaust if one or both of these were leaking. I dont really know what else to do other than to take the top off, and replace the regulator. Its the cheapest fix. $90/regulator from Dealer, $60/from Autozone.

Anything setting off a light with you guys here? These symptoms point to anything? HELP?

On replacement parts remember OEM dealer parts only hurt one time.
That el cheapo aftermarket stuff can bite you in the rear many times.


Proper testing step by step will tell the story on it.
The return line is the small line from the engine down by fuel filter.
The large line from filter to engine is the pressure line.
Just pinch off the return line on the rubber part of hose.
If pressure jumps up to fuel fuel pump pressure/75-85 lbs of pressure with return line pinched off that tells you the fuel regulator is bypassing to much if pressure does not hold but 55 lbs with return line not pinched off.
Make sure the fuel pump is putting out good pressure first thing. By pinching off return line.
Then check the fuel regulator for leakage and bypassing pressure.
And if it is bad get the regulator from the dealer.
Remember OEM dealer parts only hurt one time.
The 98 does not have a common leak on the spider assembley.
Not even a spider assembley. Each injector is seperate.
Run all of the fuel pressure test and then go for it.

After you get fuel pressure up to par there is a injector balance test that can be done with a good engine capable scanner. But you will have to have good fuel pressure first to run it.
MT

[JoshBarber]

might be worth noting as well.

when you actuate the throttle from under the hood with the engine running, the two fuel lines that enter the top of the intake look like they're jumping up each time the throttle is goosed, and a strong vacuum sound can be heard from it.

Is that normal?

[MT-2500]

Originally Posted by JoshBarber

might be worth noting as well.

when you actuate the throttle from under the hood with the engine running, the two fuel lines that enter the top of the intake look like they're jumping up each time the throttle is goosed, and a strong vacuum sound can be heard from it.

Is that normal?

The fuel lines that go in there are both under fuel pressure. Big One the in line and small one return. They should not be lose or leaking.
That may explain the gas smell.
They are held down with one screw and a clamp that fits over the shoulder on fuel lines.

The vacume leak noise would be another problem. There is a seal around the injector body where the fuel lines and wiring goes into intake.
Check for vacume leak there and other places on intake.

If your mechanic had the intake off he is the last person that worked on it.
Are you going to fix it yourself or take it back to him to finish up the job?
MT

[JoshBarber]

Originally Posted by MT-2500

The fuel lines that go in there are both under fuel pressure. Big One the in line and small one return. They should not be lose or leaking.
That may explain the gas smell.
They are held down with one screw and a clamp that fits over the shoulder on fuel lines.

The vacume leak noise would be another problem. There is a seal around the injector body where the fuel lines and wiring goes into intake.
Check for vacume leak there and other places on intake.

If your mechanic had the intake off he is the last person that worked on it.
Are you going to fix it yourself or take it back to him to finish up the job?
MT

I just went and bought the regulator from the dealer for approx $90. Will I need a gasket for this upper plastic intake cover when I reinstall? I planned on tackeling the job tonight when I get out of work, why do you ask? Frankly I'm tired of the hassle with the mechanic I was using, and have little faith in his ability. These symptoms I've mentioned of a vacuum sound ("pfffft"), and jump on each goose is not supposed to be heard? I just tried to tighten the screws, and it didnt make a difference. Its not just the lines, its the whole "fuel meter body" that they attach to thats moving/making the noise. It only does it on a hard quick goose of the accelerator. Similar to the sound the air intake makes. Should I assume the seal around the injector body needs to be replaced? Or is the regulator part of what could cause this? I just called the dealer, the seal only comes as a kit with the lower intake gasket etc.
Could someone with a 98 style Blazer check this on theirs? Do you hear a vac. sound when you goose the accerator, or see any movement in the two lines entering the intake? I'm going to spray it with a small amount of starting fluid to see if it sucks in and changes the rpms.

[MT-2500]

The reason I as.ked was it sounds like the mechanic done messed it up.
If you are going to do it yourself get the intake gasket and seal set.
It actually sounds like the seal was left off or fell of of the injector body.
if the seal was on there the injector body would be fitting sung in the intake.
With no vacume leak.
If the fuel lins are lose or leaking see if the dealer has the seals and plastic bushings for the lines. There is several seals and washers/bushings for each fuel line.
The dealer should have a good picture of them. Have him print it off for you.
Nothing like fixing something after someone has messed it up.
Good luck
And let us know how it goes.
Mt

[JoshBarber]

Originally Posted by MT-2500

The reason I as.ked was it sounds like the mechanic done messed it up.
If you are going to do it yourself get the intake gasket and seal set.
It actually sounds like the seal was left off or fell of of the injector body.
if the seal was on there the injector body would be fitting sung in the intake.
With no vacume leak.
If the fuel lins are lose or leaking see if the dealer has the seals and plastic bushings for the lines. There is several seals and washers/bushings for each fuel line.
The dealer should have a good picture of them. Have him print it off for you.
Nothing like fixing something after someone has messed it up.
Good luck
And let us know how it goes.
Mt

Along with the regulator; I actually picked up the full gasket set (which includes the throttlebody gasket/upper intake cover gasket, and the one we're mentioning) just in case, as well as a second kit for the plate that the system screws into (which includes fuel line o-rings etc) at $30 a piece. I'll return it/them unopened if they're not needed. If I do a job I know its done right, not half ass. Last thing I want to do is get into it tonight and find out I'm without a simple piece that needs to be replaced (after the dealer is closed). I'm hoping just the gasket came off as suggested, and thats where the vac. leak/movement is coming from (as opposed to the mounting bolts that secure it) Would you think the seal itself, if missing, would allow that extra movement? It might have been this way BEFORE he even took off the cover, I'm not sure. But I couldnt detect any change in RPM with the starting fluid. Regardless, I'll replace anything that's suspect.

[MT-2500]

Originally Posted by JoshBarber

Along with the regulator; I actually picked up the full gasket set (which includes the throttlebody gasket/upper intake cover gasket, and the one we're mentioning) just in case, as well as a second kit for the plate that the system screws into (which includes fuel line o-rings etc) at $30 a piece. I'll return it/them unopened if they're not needed. If I do a job I know its done right, not half ass. Last thing I want to do is get into it tonight and find out I'm without a simple piece that needs to be replaced (after the dealer is closed). I'm hoping just the gasket came off as suggested, and thats where the vac. leak/movement is coming from (as opposed to the mounting bolts that secure it) Would you think the seal itself, if missing, would allow that extra movement? It might have been this way BEFORE he even took off the cover, I'm not sure. But I couldnt detect any change in RPM with the starting fluid. Regardless, I'll replace anything that's suspect.

You are on the right track.
When you get the intake off you will see the injector body is on a floating/sliding type of bracket on the bottom of it.
The seal on top of it where it goes into the intake holds the top of it in position.
When you put the intake back on oput a little lubercant on the seal and intake where it goes in.
Good luck and let us know how it goes.
MT

[JoshBarber]

Originally Posted by MT-2500

You are on the right track.
When you get the intake off you will see the injector body is on a floating/sliding type of bracket on the bottom of it.
The seal on top of it where it goes into the intake holds the top of it in position.
When you put the intake back on oput a little lubercant on the seal and intake where it goes in.
Good luck and let us know how it goes.
MT

I'm mid-job right now. Taking photos for a HOW-TO to be posted later

[JoshBarber]

OK, top is off, and these are my findings. MT, if you're looking at this and can help. I'd greatly appreciate what this photo tells you. The three injectors on the passenger side have a small reserviour above them that are vented. All three have liquid pools in them that smell more like oil than gas...but I could be wrong. The injector closest to the firewall had the most in it. Please get back to me asap, you can call me if you feel up to it. thanks
J

[MT-2500]

Originally Posted by JoshBarber

OK, top is off, and these are my findings. MT, if you're looking at this and can help. I'd greatly appreciate what this photo tells you. The three injectors on the passenger side have a small reserviour above them that are vented. All three have liquid pools in them that smell more like oil than gas...but I could be wrong. The injector closest to the firewall had the most in it. Please get back to me asap, you can call me if you feel up to it. 401 787 3176
thanks
J

I do not see that is is anything to worry about on it. They are more or less dead spots that collect fuel and oil. May not look good but will not hurt anything.
Just sponge the old gas and oil out.
MT

[JoshBarber]

Originally Posted by MT-2500

I do not see that is is anything to worry about on it. They are more or less dead spots that collect fuel and oil. May not look good but will not hurt anything.
Just sponge the old gas and oil out.
MT

ok, can you give me a call and I'll write everything down after on the howto/findings? it'll take me two minutes to explain what I have and maybe you can tell me what to do ?

The regulator showed no signs of leaking...but underneath the spider assembly, all 6 ports seemed to have fuel in them, as if they were all leaking. Is this common?


Should I wait till tomorrow and replace all 6 lines? Or at least their 2/orings per injector? And also, the question regarding the vac leak in the spiderassembly...the bolt that holds the bracket is secure, but theres free movement in the bracket itself. Thanks
Like I said...please give me a call asap..Im waiting to continue.

[solarflareq]

The fuleregulator is on the left side of the engine if your leaning over the hood "towards window from grill" if you have one side super clean looking "gas washes down oil" and one side of the plenum oil covered like in your pick that also would tell me its leaking.

you can turn your key on " DONT START IT " have someone just turn the key and watch the regulator for a leak. if it presures up and no spray.. aswell as your left side of the plenum when your faceing over the hood looking in is not washed looking. its probly not doing anything major if anything at all. then your problem most likely lies elsewhere..

you will probly need a dif torks bit, one with a hole in the center to get that regulator off the spider if i remember correctly.

[JoshBarber]

thanks for the call MT. I'm going to try to just replace the 12 Orings on the injectors...as the approx $75/each to replace the injectors...is WAY over my budget.

cross your fingers! I'm going to try to ask one of the techs at the dealership if they think anything is wrong where those ports had pools in them. Something seems wierd there....but I hope you're right that its normal.

I'll report back on the Orings etc.