car is tuned... still having issues

[inphiniti]

ok im going to try and make this brief. long story short, most of you know i recently did some work to the motor(HCI w/ stock block) most if not all of the mods are in my sig.

i got the car tuned/dynoed last week. heres my deal

in the morning, the car has to run for atleast 10 minutes before i go to work. its not really that cold in RI, its about maybe around low to mid 50s give or take. if i let it warm up anything less than that, it runs like a bag of ****.. it constantly wants to stall. but usually after warming it runs fine. sometimes ill come to a slow complete stop and the RPMs will surge to a little over a grand, dump back down to almost nothing, go back up and then cut out and stall.


my father the other day let it warm up for a few minutes and went around the block, and stalled it about 7 times just going around the block and back into the driveway. friday i let it run when leaving work, left and go stuck in some traffic. it stalled about a dozen if not more times from the off ramp to my house(about 2-3 miles, again give or take)

the race shop when tuning said it didnt stall once besides trying to get it ON the dyno w/o a tune. he did however mention turning up the idle, but didnt really want to if it wasn't needed.

any suggestions? is all this supposed to happen? i really wanted daily drivability out of it, w/o having to constantly turn the ignition.. any help would do fellas!


..so much for keeping it brief i guess LOL

 

[ProKiller]

what is the idle set at now?

 

[GTA_V6_Mustang]

If those are all your mods then to me sounds like ur using injectors that are way too big for an stock shortblock 302. Also what MAF are you using?

 

[302GTS]

I plan on reading this thread quite a bit... I'm looking into h/c/i, and daily driveability is a MUST, so you've got my interest.

On topic, I'd take it back to the tuner. You payed him to get the driveability down, and he didn't.

 

[GTA_V6_Mustang]

I plan on reading this thread quite a bit... I'm looking into h/c/i, and daily driveability is a MUST, so you've got my interest.

On topic, I'd take it back to the tuner. You payed him to get the driveability down, and he didn't.

If you want great driveability from a H/C/I 302 you need to do it right. I make a hair over 300 and Drive mine everyday no heating up at all in traffic or on the highway and it gets better mileage then my teal stang that just has a ported cobra intake and bolt ons. Its all about how you put it together. And personally for the original poster I believe your using injectors that are way too large. Especially if your still using stock MAF.

 

[Stanger007]

I'd take it back to the tuner. Your combo is far too mild to have problems.

I have tuned 80lb injectors on cars that idle at 750rpm. Most cars nowadays run 60s. The injectors are fine and can be accounted for in the tune.

Wes

 

[Stanger007]

P.S. The fix is making sure the fueling is correct at idle and making sure the neutral and DRIVE idle airflow functions are setup correctly.

Wes

 

[inphiniti]

If those are all your mods then to me sounds like ur using injectors that are way too big for an stock shortblock 302. Also what MAF are you using?

i have a 80mm PMAS maf for 30lb inj.

my buddy actually turned the idle up last nite and in traffic today it didnt stall, that could've been my problem. my car usually idles around 800ish give or take. either way im going to keep my eye on it for the next few days and see how it rides...

does weather have anything to do with it? im sure it does, but how does the cold affect the vehicle?

 

[turbogt]

If those are all your mods then to me sounds like ur using injectors that are way too big for an stock shortblock 302. Also what MAF are you using?

He could be running 60's and it wouldn't make any difference..

 

[ProKiller]

i think you just need to up the idle more. 800 is too low i think for that cam. you could always confirm this by calling up anderson's tech line. they are very helpful.

 

[GTA_V6_Mustang]

He could be running 60's and it wouldn't make any difference..

If he wasnt running the right MAF hell yes it will cause a problem. If you read what I wrote before I asked what MAF he was using because he said he listed all of his mods and a matched MAF was not listed. Thank you very much. If he was on 30# injectors and stock MAF thats a big problem.

 

[GTA_V6_Mustang]

i have a 80mm PMAS maf for 30lb inj.

my buddy actually turned the idle up last nite and in traffic today it didnt stall, that could've been my problem. my car usually idles around 800ish give or take. either way im going to keep my eye on it for the next few days and see how it rides...

does weather have anything to do with it? im sure it does, but how does the cold affect the vehicle?

Ok so you have a calibrated MAF thats fine.

 

[grngt50]

Ok so you have a calibrated MAF thats fine.

but with a dyno tune it shouldn't matter either way

-J

 

[final5-0]

Just a bit of basic info

This guy stated that he had a custom tune

When you see that kind of thing
then
You can know that there COULD be more options than just ....

A certain size meter caled to a certain size inj

The Ford OEM meters are NOT caled for ANY sized inj

Case in point

Look at my sig and see I ran 30's with the little OEM meter

I did have to move up to a different meter
but
The reason for doing so had nothing to do with inj size

It was all about the meter would not accurately read the amount of
air the motor was pushing through it

OR

As many have most likely seen ... I was pegging the meter

A meter caled for inj size is OLD SCHOOL :Word:

The idea came from the Fox pcm's
and
It just don't work as good on our pcms

As said by the folk above

You can run very large inj's and a good tuner can setup the pcm to deal
with the issues you certainly will have at low pulsewidth conditions

For what it is worth
On a combo such as we have here .......

I also feel 800 for idle is a bit low

If you get all involved in what the pcm is trying to accomplish at idle
and then
When you got a bunch of hot rod parts

Like Wes said ... ya gotta hose around with the settings a bit
and
Its more easy if ya start out the hosin with a sightly elevated idle :Word:

I think that tuner just needs another opportunity to deal with
the drivability issues

Grady

 

[inphiniti]

so basically this is all expected, nothing out of the ordinary since all the works been done? i know he mentioned some tweeking was going to be done down the road... good thing is it actually stalled on my buddy who put the motor together, so now he can better explain to the race shop what its doing(for those of you who might know him, i use Dez Racing in Seekonk, MA for all my stuff besides the HCI swap we did.)

other than that, this car is a completely different person. it sounds amazing, and handles great. finally can spin some tire w/ this thing!

thanks for your help guys

 

[95Vert383AOD]

Hey i personally don't think the Injectors are too big especially if calibrated. I ran 24's and had a similar issue with my 302 in a Fox car. Check your fuel pressure....You SHOULD have an aftermarket adjustable anyways.

Second i believe you said you have a .544 lift cam in another thread....I think thats your problem. I ran a pretty radical Lunati cam that would damn near rock the car at idle. A cam like you have you would want to run your idle at around 850-900.....But the shop has to program 850-900 rpm into the tune or your computer will make it surge even more.

Warm it up and bring it on by....but ive noticed personally that Large cammed motors don't like cold weather. Hell mine would even backfire a little until warmed up.

 

[inphiniti]

chris, wht do u mean by the cams lift being my potential problem?

 

[95Vert383AOD]

chris, wht do u mean by the cams lift being my potential problem?

I noticed when i built my 302 that everything was fine until i tossed the Lunati cam in there. .544 is alotta lift for a 4 season DD 302 car. I had the exact issues you are talking about. In the summer time they were almost not there.

Believe it or not i have a similar lift in my 383 stroker, Way too small of a lift for a 383...But it has awesome drivability to the point where i have no check engine light and im not running a chip.

I'll send give you my number seeing you live really close and i have already bumped into you.

 

[R.J.]

Try setting your idle with this procedure or take your car to karl's East Coast Speed (Warwick) and have them retune it.

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC.

Now remember we adjusted the set screw on the throttle body. That means that the voltage reading from the TPS sensor has changed. It should read between .96 and .99 volts. Anything outside of that range will cause all sorts of issues including misfires and rough idle.

you will have to back probe the TPS connector. With the connector attached to the TPS stick a paper clip into the rubber boot on the connector where the top and middle wires go into the connector. The rubber is very flexible the paper clip will slide in between the rubber and the wire.

Set your multimeter to volts. Turn ignition to ON. Then place your multimeter leads on the metal pins. If it comes up as a negative that is okay as long as you are -.96 to -.99. If you get this reading then great you are done and hopefully your issues are gone. If not proceed to step 9

This is where and extra pair of hands come in handy. Using a large screw driver you will need to loosen the bolts that hold the TPS. DO NOT USE A SCREWDRIVER THAT IS TOO SMALL BECAUSE YOU WILL STRIP THE BOLTS. They probably will be really tight so you have to really lean on the screwdriver and use some finesse.

Once the bolts are loose you will need to move the TPS up or down and continue to read the voltage. Once you get it to the desired setting you can retighten the bolts. What I do is I find .97 and then as carefully as possible I tighten the TPS down. what will happen is the voltage will change usually to .96 or .98 but that it okay. Once you are done with this manually open the throttle body a few times and close it then reread the voltage and make sure it is still within our desired range.

Depending upon how loose your set screw was you might want to cover it in RTV to hold your setting. At this point you have CORRECTLY reset you idle.