Help!!! Urgent!!! Im Going Insane!

[chirs]

Help!!! Urgent!!! CAR WONT IDLE!

Hello everyone my name is Chris. I recently rebuilt my old 302 engine. It has been bored 30 over and has the complete Explorer/Gt40 induction system, heads, intake and such. I have deleted all smog equipment and properly blocked off all of the corresponding vaccum lines. I also have longtubes and a non-catted x-pipe. Well the car will not idle at all.

The car will not idle at all unless i keep my foot on the gas, in which case it will idle well as long as the rpms stay above 1k. I believe that the tach is off maybe 100-200 rpms as the tach never goes all the way down to the peg. Anyhow, the car will always start up and then flucuate for 1/2 a second then die unless i mash the gas.

Well, I began by cleaning the idle air motor and such. I pulled the codes and i got 314 and 311 Thermactor air inoperative on the right and left side, makes sense because i have deleted both the smog pump and egr. I also get code 327, egr, again which makes sense. I also am getting 563, High fan control circuit failure which i find strange because the fan does turn on and does stay on when car reaches high operating temps.

Well in pulling the codes, i used a code scanner. When i preformed the 327 and 563 are KOEO, key on engine off, and the 314 and 311 appear along with the 327 and 563 while KOEO, key on engine on. Well during the test mode that the handheld scanner performs to pull the codes, the car will actually idle by itself. It idles at around 1k rpms, nicely, until the test ends. At this time, the car will immediately die. This has happened numerous times. The only time the car will idle by itself is in Key on Engine on Test mode. Other than that nothing. While it does idle a little high, again i believe that my tach is off 100-200 rpms. So the actual idling i believe is pretty close.

This is extremely bazzare and i dont know what to do. Has anyone ever had similar problems. Tomorrow i will use a volt meter and measure the voltage on every freaking sensor to see if it is bad.

Also, i have checked for vaccum leaks with the good old method of spraying starting fluid by all vaccum lines and seeing, with myself keeping rpms steady, and my dad spraying, if we could get any kind of increase in rpms. NOTHING!

HELP. THIS IS FRUSTRATING. Thanks for your time. Chris

 

[chirs]

Follow UP

My timing is set to 14 as per instructions by crane cams as i am running the 2031 cam. I also have gapped my spark plugs to 45 as per their instructions. The car ran the same way even when before i had run 10 degress timing and 54 as the spark plug gap.

I have driven car, keeping the rpms from dipping below 1k, and the car seems to drive fine. I took it easy, since on the newly rebuilt engine, but the car does not seem to miss in the higher rpms and seems to have decent power. Again, i have not jumped on the throtle or anything, just by feel its ok.

Thanks again.

 

[rockin_rick]

There is no way around it, you need a computer tune. Most likely your idle A/F is off or your IAC flow requirements now are different. Most likely, your tricking the EEC with a MAF cal and larger injectors, and this can cause problems, too.

It's time to bite the bullet and invest in a tune/tuning device.

Rick

 

[mo_dingo]

what cam are you running. With a narrow lsa cam you will have problems getting the car to idle right w/o a custom tune. Completely normal.
Scott

 

[hbk_136]

Thats the thing. I have stock injectors and stock MAF. I am running a Crane cam # 2031. I dont believe its that radical of a cam that i would need tuning. Can anyone else back up the need of a tune?

 

[hbk_136]

Oops wrong account, I am on my bros comp. Still, same person though!

 

[GRGT1994]

Ya, I think you are right that you don't have that radical of a cam, and you should be able to get it to idle without a tune. At least to idle acceptably (maybe some surge and roughness). I went with the AFM b-31 cam on my top end build with the same thought that I could get away without a tune for a while.

When I first fired it up, I had big problems, kind of like you describe. The first thing I did was put some gas in the tank, as I ran it dry so I could drop the tank and swap the pump (but like an idiot I forgot about that on the first start up attempt). Then I played with the timing a bit. The timing made a HUGE difference. Try dialing it back from their recommendation a bit, and see if that does anything.

Of course, I did some fuel mods (I think you said yours is basically stock), so you still might be pushing the fuel system a bit over with your set up.

Oh, and make sure to once over everything else too. Make sure nothing has come loose or is out of order. I had the CAI come loose from my TB a couple of times (don't know why I got the stupid thing anyway). The first time I didn't even notice.

Hope that helps, good luck.

 

[final5-0]

Hey Chris

If you would be so kind to get you a sig together that spells out all of your mods it sure would make things easier for everybody that tries to help.

btw ...... it sure sounds like a v leak to me.

Later
Grady

 

[94GTMOOSE]

Try the DIS module... I've had the same problem with my stock motor. and also my Tauras SHO and Thunderbird, same symtoms. not sure that anyone will agree but thats my two sense

 

[FastFord]

Well... I had similar symptoms... Car was fine, but if i stopped it would surge and die. For my case, it was the O2 sensors... But you pulled codes... And it does sound like a vac leak as well!!

 

[chirs]

Well, ill begin by stating my mods.

Explorer Gt40 heads (non-P), explorer upper and lower intake, and Crane 2031 cam. Those are the only performance mods, except for slight longer pushrods. I also have bbk-long tubes and non catted x-pipe. The catback and everything else is the same on my car from the fuel injectors to the mass air.

I have already searched for vaccum leaks by spraying starting fluid by all vaccum lines and not once could i get teh car's idle to raise. Of course this was with me holding the idle at 1k steady, and my dad sparying the starting fluid on the lines.

The strange thing is that when i perform a Key on Engine on test using a handheld scanner to pull engine codes, the car will idle just fine. Allbeit slightly higher that i would expect 1k, but it idles fine with no surging. Immediately following the conclusion of the tests, the car will die again. I have went over all wires, grounds, and vaccum lines and everything looks good. I just dont understand how the computer can make the car idle when in test mode, but at no other time will the car idle. Any other suggestions?

 

[chirs]

Well, ill begin by stating my mods.

Explorer Gt40 heads (non-P), explorer upper and lower intake, and Crane 2031 cam 6.3 trickflow pushrods. I do have bbk-long tube headers with a non-catted x-pipe and stock catback at this time. Everything is basically the same on my car from the fuel injectors to the mass air.

 

[GRGT1994]

Did you try adjusting the timing?

 

[hbk_136]

Timing was orginally at 10 degrees. I called crane and they recommended 14 degrees. Neither one fixed the problem. i will be replacing the iac tomorrow. If that fails to fix the problem, i will just adjust the idle screw to force it to idle at around 1k. I sprayed starting fluid all around the various vac lines while holding the idle steady. No where was the starting fluid used did the idle raise. So, i dont believe it is that. The only wierd code im getting is 563 which is a high fan speed curcuit malfunction. The other codes are EGR and smog pump deletion problems that i expected. Thanks again

 

[a50sn95]

Let's see.
Assuming that the timing is right, which you say it is, then the TB/ISC need to be adjusted.
I just did this on mine this morning. I have a Tweecer, though to make it easier!
First, back out the idle speed set screw until it is no longer touching the lever.
Then, turn it back down until it just touches.
Make one full turn from this point to get it set.
This is were they should be from the factory.
A bigger cam will need a bit more airflow.
You can adjust this some more to allow more air in, or you can open up the ISC bypass screw back backing it out Unscrewing it.
I'd probably go with more on the set screw than on the ISC bypass.
If you had a way to compensate for the idle speed in the computer, you would then disconnect the ISC wire, and try to get the car to idle 122rpm below your desired rpm. I chose 750 with my 2031, so I got it to idle at 625~ish with the wire disconneted. This should get the ISC enough play to keep it idling.
If you don't have a way to change the idle speed, then you are trying to achieve an idle speed of 640 rpm, as this is what the T4M0 is set for. You may not be able to get it to idle that low (525~ish) with the wire disconnected.
Finally, if you move the Idle speed set screw, make sure you go back and adjust your TPS to .96-.98, so the computer knows it is idling.
This picture is an aftermarket TB, but it should be similar on a stock TB.
BTW, the 2031 is for 1.7 ratio rockers. You don't list them in your mods.
It shouldn't be much of an issue, just less lift than the cam is designed for.
Hopefully some of this will help....
Dennis

 

[GRGT1994]

Let me try this again. Try various different timing settings. Move it from about 0 degrees to maybe as far as 14 degrees, in very small increments. Turn the distributor real slowly. Let the engine run at each point for a bit. Stop when you think you have settled on the smoothest point.

This makes a HUGE difference. I had the EXACT same symptoms that you are describing. And the procedure I just described worked wonders.

The timing settings you got from the manufacturers are only a recommended starting point.

Not saying that will do it for you, but maybe it will.

 

[final5-0]

Chris

If you do have a v leak it most likely will not be a hose due to the fact that you've had the motor torn down and put back together.

A more likely place for the leak would be places like:

Lower intake gasket
Upper intake gasket
egr gasket
tb gasket

Anywhere you've taken stuff apart if you know what I mean.

Later
Grady