Not much to explain, but after I drive the car I often open the hood and if i listen closely I can faintly hear a hissing coming from either the number 1 or 2 fuel injector. I don't think i can smell gasoline in the engine bay, but i can smell it when i'm driving with the windows open, and it's qutie strong! not to mention i'm gettinb about 15 miles to the gallon on the highway! what's going on with my new love!??!

i'm so tired...

 

Maybe the fuel injector isn't seating correctly on the manifold, causing a vacuum leak...

 

how do i torque them in since they're just philips head screws?
also, could it be a leaking o-ring seal, and what abou the fuel economy?

 

They should actually be 8mm bolts holding the injectors in place (unless someone replaced them). The injector O-rings do get brittle and crack, allowing for the possibility of vacuum leaks (classic hissing sound). You can spray some starting fluid on that area & see if the engine RPMs change.

 

yeah i'm getting a reasonably high and unstable RPM btw, when it's cold it'll be at about 700, but when it's all warmed up, it'll go from 1000 to 1200 then back down and up and down and up while I'm in neutral.

Timing IS on at 8 degrees BTDC.

I have to go to bed before i pass out, but i look forward to more responses, thanks nismo Its just that i have a 100 mile trip coming up and 9+ gallons is going to be VERY costly so i hope to fix the problem b4 saturday...

 

I don't know if this is breaking regulation by posting again, i jsut NEED HELP SOON!! i'll clarify the symptoms

I'm getting about 8MPG on the highway, rarely rev it over 3K, and when the RPM drops from 2.5K to 1.5K or when there's a sudden drop a sound from the engine is emitted and it sounds like a hiss or a leak. this happens when the throttle is closed or the load is taken off the engine. Is it a vacuum?!?!?

Also! there is hissing coming from the fuel injector and so far i'm in a rut!! HELP!

 

Did you read my post above???

 

get brake parts cleaner, electrical cleaner, whatever, and use the little plastic tube extension and spray around the injectors, where the manifold meets the head, vacuum lines, etc. Also pull your oil filler cap and see if it causes the engine to change, also check your oil dipstick to make sure that's sealing.

 

Well, this may seem silly, but I took the fuel injectors off to have them cleaned, but how much should I torque those little bolts back on, the ones that go through the fuel injector holders/seals?

 

Not sure what the actual torque should be, but I can tell you from experience that overtightening them will cause the plastic housing to crack.

 

Indeed.... just get them tight. 10ft/lbs is plenty if you are even going to use a torque wrench on that.

 

Well i've removed the fuel injectors to send them to witchhunter.com and have them serviced, but As i was taking them off, i found that hoses are cracked. At the base of the hoses are these IMPOSSIBLE little rings that wrap around the nozzle feed on the injector. as you can see i've taken about an hour to tear this aluminum bit to shreds, but it's still not coming off, is there an easier way?

<a href="http://photobucket.com" target="_blank"><img src="http://i81.photobucket.com/albums/j223/thetremendoustim/HPIM0806.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

 

This stuff eats plastic,rubber... do not put in engine.
And I believe this stuff eats metal, similar to how you clean a corroded penny with vinegar.

Carb cleaner's fine to go in the engine though Dunno if it'll make any difference to the idle. But the starter fluid suggestion sounds best to me, assuming its not too rough on old brittle rubber hoses taht it might accidentalyl run into.

rx

 

With him only getting 8 or so mpg, I have to wonder if the water temp sensor is bad, causing the computer to think the engine is always cold, hense firing the cold start injector full time. Possibly a bad O2 sensor giving a false lean reading? Also sounds like some vacumme leaks messing with the idle.

 

hey what kind of vacuum leak should i be looking for? i still have my oxygen sensor to replace, i'll do that probably tonight. I was thinking maybe even a bad air mass meter? my temperature is working fine. Is there a way to check and clean a air mass meter?

 

dude....



you just destroyed your injectors. Those hoses are supposed to be on there for the life of the injector. You don't take them off and replace them.

replace the small and large round rubber rins that go at the tip of the injector and further up in the middle of the injector. Should be $10 or less for a set for all six injectors. Make sure they are lined up good and screw them back in.

Also, did you remove the fuel rail first?

On the vacuum leak again, check all the bolts holding the intake and exhaust manifold to the head. Make sure they are snug.

 

yeah i disconnected the fuel rail, and moved it out of the way. I sent them to get cleaned and they came back with no hose, so i just got some new hose and hose clamps, I don't know what to do but they've been working fine, no hissing, no nothing so far....i hope it'll last. But When i get home i am going to try to clean my air mass meter, hopefully that will help, since it's '81 stock.