so today i noticed that when cruising down the interstate, my q started to buck slightly as if it was misfiring. the only check engine light i have is for the IACV, i have been driving with iacv cel since i got it running 4 months ago and it never bucked or misfired just idled a little lower than it should. Now i have a brand new distributor, original spark plug wires that look worn out and are the likely culprit.
the best part is, if i floor it, it doesnt miss a lick and goes just fine.
new plugs
new distributor
new fuel filter
maf is clean
air filter new
throttle body clean
the reason for this post is to ask, does the idle control valve have any function other than at idle, or should i say is it possible for the iacv to affect driving at a constant speed?'
i show no codes for misfires at this point on my scanner.
Sputtering randomly
Re: Sputtering randomly
IAC increases idle when A/C is on to compensate for the extra load. Missing at speed indicates your plugs may be too wide a gap or too high a resistance on your plug wires. When resistance increase your ignition system via a coil or coils must create a higher voltage and that build up of electrons takes time to build up to break free as when it jumps a plug gap. No code says your just at the threshold.
You state the HT leads are bad, check your distributor for cleanliness, check plug gaps with a wire gauge not a flat feeler type and verify your wires. Verify the IAC and its sub assemblies. EGR may be carbonized.
You state the HT leads are bad, check your distributor for cleanliness, check plug gaps with a wire gauge not a flat feeler type and verify your wires. Verify the IAC and its sub assemblies. EGR may be carbonized.
Re: Sputtering randomly
noticed that on the passenger side two plugs had some oil on top of them. cleaned it up and threw a bead of silicone between the head and valve cover. talking about maybe half a teaspoon of oil in front two cyl.
i hope that and the wires are the culprit
i hope that and the wires are the culprit
Re: Sputtering randomly
well it appears that i have solved part of the problem. set of new plugs and wires appears to have cured the missing, however it will occasionally die at idle and the idle jumps from 1200-500 randomly while sitting still, i have a CEL for p0505 aka iacv so i presume i need to change this, next question how difficult is it to change this valve, it appears to be upside down bolted to the intake manifold. how in the world are you supposed to get to those bolts arrange the gasket etc... i hope you dont have to pull the manifold to perform this task? pics?
Re: Sputtering randomly
Before changing that valve test it. When warm idle is 750, then turn A/c on idle should raise. You may have a faulty EGR vacuum or plugged with carbom
Re: Sputtering randomly
well i cleaned the egr pretty good before i put it back on a little while back, and i dont have any codes for egr. the thing idles at target most of the time, but randomly will idle at 1100 or in gear low at 550-600.
with ac on or off it stays at the same rpm, only time rpms go up to 1100 is when i put it in park sometimes
only code i throw is p0505, and this is something new, when idling in gear it will occasionally rev jump and or just stall out where is best place to stick on manifold to reach the IACV
with ac on or off it stays at the same rpm, only time rpms go up to 1100 is when i put it in park sometimes
only code i throw is p0505, and this is something new, when idling in gear it will occasionally rev jump and or just stall out where is best place to stick on manifold to reach the IACV
Re: Sputtering randomly
to add insult to injury, i attempted to startup my ride and BAM pop. popped the hood and low and behold busted battery terminal. of course me being me i had an extra battery cable in the truck. 10 minutes later she starts again.
Re: Sputtering randomly
to add insult to injury, i attempted to startup my ride and BAM pop. popped the hood and low and behold busted battery terminal. of course me being me i had an extra battery cable in the truck. 10 minutes later she starts again.
Re: Sputtering randomly
so i noticed that for some reason after replacing the battery cable my ac stopped working, checked the fuse it looked good but was burnt looking. i changed the fuse but no dice. got to work turned ac on and it worked and the SOB idled up to 1100 then settled at 950, with ac off it went down to 750 WTF so my IACV WORKS BUT is likely a little dirty? this is the first time i have seen it work since i got it running 4 months ago. would a weak ground cause this? no way huh
after reviewing manual i saw that it states to set base timing at 15 bdc well mine is set to 8 due to evidently reading the wrong post. perhaps that will cure my low idle under load. i am simply not getting enough timing. ha
after reviewing manual i saw that it states to set base timing at 15 bdc well mine is set to 8 due to evidently reading the wrong post. perhaps that will cure my low idle under load. i am simply not getting enough timing. ha
UPDATE
still sputtering randomly, "cutting in and out" but when you give it gas its fine. So its only doing this under light load at speed. TPS? ONLY CEL is for the IACV still. I noticed that when floored the tps % is at 89% percent, ive seen this on other cars but was curious what other people show at WOT on a scangauge. per owners manual there appears to be a idle learn procedure by which you disconnect the tps is this a tps calibration?
Sputtering under light throttle at speeds above 30 it is noticed. floor it and it accelerates flawlessly.
new ground cable, plug wires, spark plugs, stopped doing for 4 days now its doing it again.
Sputtering under light throttle at speeds above 30 it is noticed. floor it and it accelerates flawlessly.
new ground cable, plug wires, spark plugs, stopped doing for 4 days now its doing it again.
the most self anwsered post in history
so it appears this is becoming more of a blog than a forum, anyway i believe i have located the problem for good i hope.
i was following procedure for setting the timing where you unplug the tps etc... well low an behold the lower connector "closed throttle position" was loose and no fully connected. the two plugs simply don't clip onto the tps sensor. had to zip tie them in a crazy setup and so far so good.
Since i have gutted my airbox i decided to move my IAT into the the air box. I extended and made a wire harness that i drilled a hole in the resonator pipe feed the wire up through the hole and out the bottom of the box, ran the wire along the edge of the lower air box and to the sensor located on the side of the box. pretty slick and it works flawlessly.
the timing was dead on.
i was following procedure for setting the timing where you unplug the tps etc... well low an behold the lower connector "closed throttle position" was loose and no fully connected. the two plugs simply don't clip onto the tps sensor. had to zip tie them in a crazy setup and so far so good.
Since i have gutted my airbox i decided to move my IAT into the the air box. I extended and made a wire harness that i drilled a hole in the resonator pipe feed the wire up through the hole and out the bottom of the box, ran the wire along the edge of the lower air box and to the sensor located on the side of the box. pretty slick and it works flawlessly.
the timing was dead on.