Jump to content
HybridZ

air leak or fuel flow


Guest TAlchemist

Recommended Posts

Guest TAlchemist

well i found an air leak in my intake boot that got worse as the engine ran and made the hole bigger. after some work and cleaning i have managed to fix the main problem but it still acts funny.

 

it will crank and idle ok then slow down and die, if you give it gas it will run after an atempt to die when you first hit the gas.

 

i hear a sound that sounds like an air leak but is also like the sound the fuel pump makes when it pumps.

 

could it be a clogged fuel filter wistling? or another leak? cause when the engine dies or cuts off it wistles for like half a second more.

Link to comment
Share on other sites

Guest TAlchemist

well i changed the fuel filter, found another leak in the lower breather hose and fixed it.

 

it runs smoother and sounds better < less wistling sounds but still something either fuel flowing or air leaking sound >, but will run for about 3-4 seconds nice and then lowers in tone, slows a bit, then begins rumbling and starts to die but doesnt it just slows badly.

 

 

could it be fuel starvation? ie gets enough fuel to start but not to run? but if i hit the throttle it will rev and hold ok with some minor mufled backfires. is there anything that could cause it to get fuel under throttle but not at idle? or do i still have an air leak.

Link to comment
Share on other sites

Guest TAlchemist

well it is not the wiring for the fuel pump. i tried a dirrect ground and it still died, i tried a direct power to keep the pump on and it didnt do anything.

 

so i doubt it is the wiring or relays, it is either air leak or afm.

 

but can the afm suddenly stop working after it was working fine? i havent touched it or done anything to it. if it is a leak i cannot find it, i have tried carb cleaner and propane to find a leak but nothing. anyone got any ideas?

 

if i cant fix it for cheap i will just scrap the engine and start shoping for a V8. i wanted the stock running so i could get the car driving and fix up everything before i do the v8. but i am not going to waste more money on an engine i wont keep.

Link to comment
Share on other sites

Guest TAlchemist

well now i fixed another problem, the IAC valve was not fully connected and causing a vacuum leak, fixed that and the upper breather hose and the engine runs much lower rpm by sound.

 

i find that if i use a screw driver to raise the little flap in the afm and the engine will speed up a second but hold on steady, if i push to much more it begins to die like when i had a vacuum leak. if i let the flap back down it lopes a little, not much but it is much better than before, i think my timing is still off, i know i need to drop the oil pump and adjust the distributor shaft.

Link to comment
Share on other sites

Guest livewire23

well, now that I am a *senior* member :D , I think I'll take a shot at helping here. I've had this same problem on my Z, there are a few things you should look at. First of all, it sounds to me like you're running lean. take off the black cover on your AFM, and while its running, turn the counterweight clockwise a little bit. if you're idle improves, I believe that means you are leaning out at idle. You might want to probe all your sensors, although they're probably good. Also, find a timing light, and check the timing. then unscrew the screw at the upper left side of the AFM a little, and rotate the big black gear clockwise about 5 cogs. At least i think its clockwise. you want to loosen the spring... This should make the car run much better. If not, pull out the fuel pressure regulator, and use an air compressor to see how much pressure it is holding. I've got clear vinyl fuel lines so that I can see when it starts bleeding off fuel. Past that, read my post "no fuel?" in this forum to see other's responses to this problem. And in the future, use the search function. More things to look at would be to make sure fuel lines aren't clogged, gas cap is venting, and injectors are spraying and not dribbling. Also take a look at the throttle position sensor, and move it around to find the optimum position. Get a service manual for precise instructions. Tell me how it turns out... By the way, mine still wont rev past 4k, so if you run into that problem, you're in the same boat as me. I've noticed that I have no O2 sensor, or even a bung for one anywhere. So this might be part of the problem.

Link to comment
Share on other sites

Guest livewire23

I'd like to mention that I bridged the connectors on the head temp sensor and the thermotime swithch sensor, and detached the throttle position sensor, and the car run "balls to the wall" as someone else put it. Im so damn stoked! Redline all around the neighbourhood. Nothing pisses the neighbours off more than redlining on a holiday. W00T!!! :rockon:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...