Just cleaned the IACV. It didnt look too bad. I think I will look for a backup just in case. Im sure I can find a used one for pretty cheap.

I also reset my ECU and installed my replacement AC line so it is good to get recharged.

Havent tried starting it yet just had to come inside and double check some things but ill let you guys know how it goes.

 

have you tryed setting base idle by unpluging the iacv and seting the tb to 650 and pluging the iacv in and reseting the ecu .. after that ajust the screw in the front of the tb to set a perfect 950 idle but must cold to do this .. if not im sure ive got a used iacv for it

 

Thats what I was planning on doing today but the car doesnt run without giving it gas.

recalibrate the tps? Remember that's what mine was doing also.

Yeah I recalibrated it yesterday.


So I am pretty sure that it is my IACV. It just seems like the motor isnt getting enough air at idle. When I give it gas the throttle body lets more air which pretty much bypasses the IACV and the motor runs. I tried unplugging the IACV and starting it and didnt change anything. Just for fun I tried another MAP sensor and that didnt change anything.

Is it pretty safe to assume that the IACV went out?

 

recalibrate the tps? Remember that's what mine was doing also.

 

yeah, its pretty safe to assume its the IACV. locally ive been talking to a few friends, they have had no issues with unplugging the iacv, and then rerouting the coolant hoses around it just bypassing the IACV all together. im pretty sure im going to do that myself. a new IACV is ungodly, and used ones are really hit or miss. most IACVs that i have seen are on their way out. But i did just pick one up w my new IM and i was told that it was a good working IACV. so i guess time will tell (when i put the IM on that is)

 

Found a local one that I am probably going to pick up. Just waiting to hear back from a couple friends to see if they have one or not.

When the IACV is unplugged it should let air into the motor correct? Unless the IACV is bad

 

it shouldnt let any in if its unpluged .. that whay you can set the idle to 650 .. if you have to turn the idle screw in a couple of turns .. that way the throtle plate is open a little .. it might idle high but it wil let it run so you can back it off

 

Well so I just picked up another IACV. About to go give it a shot and see what happens.

 

So I tried another IACV and still wont start on its own. Once I give it some gas it runs but then dies right after I let off. Any other ideas on what it could be?

I have the idle screw backed out all the way to about where it looks like its going to come out.

A week before the dragon is not when I want issues like this :icon_twisted:

 

you have to ajust the screw on the bottom ( tb pully) of the tb to open the throtle plate to get it to idle at first .. not the idle ajustment screw

 

Hmm I guess I will try that it in a little bit

 

I have never heard of having to have the plate open to idle....Im gonna guess a sensor of the sort causing this, Normally the culprit is always the IACV.Im gonna keep doing some research man ill text ya when i get more ideas.

 

I was thinking it could maybe be the MAP sensor but tried another one and got the same results. If all else fails I will go ahead and setup the throttle body so its open slightly.

My Skunk2 throttle body should be tomorrow but I will be out of town until Tuesday so I can install it then and see what happens. I think with the Skunk2 throttle body it will do the same thing. If I get off work early this week I might take it to the shop who tuned my car and see if they have any ideas on what it could be.

 

A second set of eyes come in handy, good luck man. Im in the same boat as far as ”uncertainty” right before the dragon. All I'm waiting on now is a tune and hopefully nothing blows up lol

 

Well when the idle screw is set correctly you should be able to troubleshoot the IACV/FITV by covering the holes in the throttlebody in front of the throttle plate when warmed up completely and the idle should be at 500. If it's above you would a vac leak, below/stall would be sensors or something like that.

I once cleaned my IACV, throttle body and sprayed a bunch of carb cleaner into the intake manifold, it kinda reacted like what you're experiencing but after beating on it for 20 minutes it fixed it's self. I don't think you'd have to adjust your throttle plate very much at all if any if it was idling good after your tune.

I'd set the throttle plate back to stock spec if not just a bit more. Check wiring and wiggle some stuff around, check timing, check everywhere for vacuum leaks especially the throttle body and check the fuel pressure I suppose. I'd also try turning the A/C on and seeing what happens since that raises the idle to see how the IACV reacts.

 

It was idling just fine after the tune. About a week after the tune I started getting this issue. I am beginning to think the issue isnt with the throttle body or IACV.

Are there any sensors that could have went bad that could be causing this issue where the car doesnt want to start on its own?
*Ive tried another IACV
*Tried another MAP sensor
*TPS has been calibrated
*There is no CEL

Ill check the timing when I get home tomorrow. I looked at the cam gears and they were still inline with each other didnt check the crank though. I cant turn on the AC yet since I just replaced one of the hoses and the system is empty.

 

Do you have access to another TPS that is on a known running car that you could swap over? I know you calibrated this one but TPS sensors seem to be quite the "wear item" from reading through our forums lately lol.

I would second a double checking of the wiring at all sensors on the IM/TB.

Are the plugs gapped to the proper specs?

 

This is actually a different TPS. I forgot to remove my other one from the throttle body when I sent it in to Skunk2. They are going to be sending my old one back. The TPS I have on the car right now is the one that came with it from the factory. It worked just fine on my other motor.

I double checked the wiring on the sensors and they look good. I believe the only sensors I have are IACV, MAP and IAT (I think thats what its called).

I am pretty sure the spark plugs are gapped correctly. I bought them from my tuner and he installed them right before my tune. I would hope the tuner gapped them correctly but I will double check.

 

Did you run a range colder or you running the oem ones? I ran a colder range in mine it was not really mandatory but told it wouldn't hurt.

 

They are just OEM NGK's. I can get the part number off of them when I check the gap tomorrow.

 

Yeah I was just asking don't really need it, don't thinking it's going to support your idling issue. I'm still thinking it's the tps honestly. I tried one from a working car, and a brand new one out of the box still did the same thing, it ended up being that 95mach5 had to remove those brass fittings that go around where the bolt goes into the tb to attach it to the intake manifold. Might want to take one of the spare ones and do that and get it completely calibrated. One other thing I wanted to ask you, is did you upgrade to bigger cams?

 

I removed the brass fittings from the TPS that was on my Skunk2 TB since I couldnt calibrate unless I did that. I didnt need to do it on this TPS though maybe because I am using an OEM throttle body?

I am running CTR cams

 

So ive been researching nonstop on the issue. Almost all of the threads lead back to the TPS or IACV. Next thing I am going to check is voltage to the TPS and IACV and also the continuity for those sensors to the ECU could possibly be a loose connection. Im out of town for work tonight but will be home tomorrow so I can continue troubleshooting.

Still no sight of the throttle body from Skunk2 which should have came Friday. I emailed them for tracking info. My friend did sandblast my valve cover today so I can get that painted this weekend.

One week until I leave for the trip....hopefully!

 

I figured you had already tested those with a volt meter.. Definitely the next step! faulty wiring of either of those sensors will definitely causes issues.

 

Nope not yet. I should have but didnt think about it until I started researching. If a connection to one of the plugs are bad I do have a spare engine harness that I have been stealing plugs from so that will be an easy fix.

 

See, good thing you got a guy like me that went through the same agonizing pain that you are a few weeks earlier. I'm saying that tps issue was a PITA! Until we removed the brass fittings we couldn't get it up to spec. Also we removed one of the wires that ran to it (believe it was the red wire, and ran a completely new wire to it that didn't fix it, it was all in the voltages it was putting out. I'm running a stock tb as well but an aftermarket TPS (omnipower) because the stock one that came with the Type-R TB exploded once we notched it and unscrewed it. Definitely your next step man, seriously do this for Kamikaze!!!

 

Haha yeah I should be able to test tomorrow. Hoping to find something wrong. My plan is to first check the voltages at the TPS and IACV and ensure that they are getting voltage. If everything looks good there then I will go ahead and check the continuity from each wire on the IACV/TPS to the ECU. Anything else I should check?

So what fixed your issue was it just getting the TPS calibrated to spec?

 

Yep, nothing more. Because without giving it gas it'd start, get to about 1000 rpms, shut right back off, you'd hear the abs, then try it again. After the tps was to spec, everything else was down hill from there.