no throttle response, sporatic idle
- Thread starter smilts
- Start date
-
Sponsors (?)
Oh ok I might have to look into getting one. This set up will work but isnt the prettiest. Now if I can just figure out why it isnt running.
LOL. Ok, that's a significant vacuum leak. There is supposed to be a small hard plastic line that goes to that nipple, and runs along the firewall. It goes through the firewall near the air conditioning pressure lines. That vacuum line goes to the HVAC box and provides vacuum for the vacuum solenoids that control which vents the air blows out of for your A/C.
Kurt
Kurt
Here's a picture. I didn't take this picture specifically to illustrate the position of the temperature sensor, but you can see where I stuck it in the top of the water outlet. I wasn't sure if it was going to work, because it won't show proper temperature until the thermostat opens up, but it's never been an issue. The EEC seems to stay in a cold condition operation until it gets above the temperature the thermostat opens up at anyway.
Kurt
Kurt
I dont actualy use my fan or vents and plugged that line but that also explains the blac vac line coming out of the fire wall.. Ill run a line to it today. I might look into running one of those T housings thank you.
Went to install everything today. found that my T stat housing akso has a bung that the ECT fits nicely into so it will be installed there tomorrow. Got to looking and the ect where it was on the intake wasnt the worst of that proble. But they had also when they extended the connection used the wrong plug, it fits over the connection backwards so it broke the terminals inside of the new ECT. I ordered a new plug, bought a new ect will be installing both along with the IAT in hte morning reinstalling the upper intake blah blah. Any way will let those of you attempting to help me know the rsults, I'm hoping this clears my problem up. Also I have taken a pic of the vac lines under the upper intake, Im just wanting to know if they are all routed correctly?
Everything hooked back up rechecked codes. The ECT is working. I'm honestly thinking maybe the fuel pump though I had three codes R172 R136 R334? I went around spraying carb cleaner not much happened. So I sprayed some in the air cleaner the idle smoothed out and I could even rev the engine some while spraying carb cleaner. But that's it. Oh also I reset the codes before testing and still got C 512.
Could be a bad pump but I would check fuel line pressure to confirm before replacing. Perhaps someone can confirm but I believe that the O2 sensors default lean when failed or failing. See http://www.youtube.com/watch?v=1mb4VmDd0ao
there new but i can check fuel pressure and replace the O2's.. will O2's cause problems like Im having?
Now that you have the ECT sensor working, what exactly is happening when driving that is of concern?
The problem hasn't changed at all. I still can't throttle up unless I feather and then it won't hold throttle. The ECT was just the code I had so its fixed. But yea nothing has changed.
So the engine bogs under throttle but doesn't with the MAF disconnected. Does it behave that way with the engine under load (in gear) and with no load (in neutral)? MAF is new (and is correct for the car) and the connection pins aren't bent or misaligned. It's the MAF behavior that is puzzling and would seemingly eliminate most the other possible causes for the engine to bog. Are you sure there isn't a vacuum leak caused by a broken fitting or a hose disconnected from the underside of the intake? What is the vacuum reading at idle? It should be about 18 inHg.
All of the Vac lines and fittings are brand new replaced them the other day when it was brought up. I can feather the pedal and get it over two grand and with kind of feathering it keep it around that but no higher both in park and driveing. I can unplug the MAF and it will throttle up quickly and smoothly. Havnt tried driving it like that though. However if I let off the throttle with the MAF unplugged it wont idle, it just dies. MAF is new and IAT is new. Both were showing codes at first as well as the ECT. WHen Ive seen this before a new MAF fixed it. THe only reason I thought fuel pump is when I unplug the MAF and it goes into limp mode, or full rich, its letting more gas through so it will run? Plus with the MAF plugged in, I can spray brake cleaner into the intake tube and it will throttle up and idles smoother.
BlackVert
15 Year Member
this is sounding more like a spark or fuel problem to me at this point. maybe there is a loose or burned/arc'ing spark plug wire, or a clogged fuel filter or bad fuel pressure regulator 
you also might run a compression test. who knows what you might find?
you also might run a compression test. who knows what you might find?
JonezySN95
Member
My vote goes to a bad MAF or a fuel issue. Like BlackVert said check the fuel filter and fuel regulator. Have you changed the spark plugs lately? And have you tested your injectors? They should read an ohm reading of 11-16 ohms. And as you stated it could possibly be the fuel pump IMO.
I'm iffy on the fuel regulator anyway. So I'm just going to replace plugs,wires fuel pump filter and regulator se where that gets me. by the time it runs right everything will be new yay new car!
JonezySN95
Member
Well at least you are dealing with fairly cheap parts (as of right now) so it probably wouldnt hurt to change it all on that old car anyways. Hopefully you will find the issue laying somewhere in that area.
Sad part is the fuel pump and filter are a month old. the plugs and wires are 3 months old. i did find one plug wire for the number 8 piston that is burnt and cracked from getting near the header though.
Similar threads
