surging?

[ujslost]

Ok guys got the motor in finally, been driving it around last 2 days, trying to get the computer to learn its stuff again.
Well Its got a problem that pisses me off,
heres what we got here.
timing is on 15-16 degrees btc
trickflow stage 1 camshaft
when i crank my car it acts like its carbed, wont run hardly, after i drive it a min or so its ok, whats pissin me off is this
after its warmed up and i stop at a light, it idles high for a min or so, then sometimes it idels down and sometimes it doesnt. I can come home cut it off, let it sit 5 mins, crank it and it idles around 1200 rmp or so, drive it stop let it idle, idles at almost 1500 rpms. I have tried to idle it down with the idle screw, but at 900 rmps it sounds like its about to die, (possibly just sounds this way because the cam is loping harder at a low rpm)
basically i want it to idle right, this idleing high and the low pisses me off, i want to hear the cam when im sitting still, and with it idleing high i cant and it sounds like crap.
I havent checked the TPS yet didnt think i should since, i didnt remove it from the throttle body.
I had this problem last time i put heads and crap on, i cant remember for the love of god what i done to fix it
Friggin check engine light is on also, could it be because i removed the factory temp sensor, and installed a mechanical temp guage?

[Wicked]

Friggin check engine light is on also, could it be because i removed the factory temp sensor, and installed a mechanical temp guage?

Is the IAC hooked up? Maf?

The factory temp sending unit in the left front of the lower intake only controls the gage, one wire. The sensor in the coolant tube on the right side of the intake (two-wire) is for the engine ECU. If you change it out you will screw with teh ECU.

Without the ECT your engine may be running in open loop constantly which may be the reason for the problems.

[ujslost]

nope not the ECC coolant, i changed the correct one, the one beside fuel injector driver side, all the other crap is plugged up

[Wicked]

nope not the ECC coolant, i changed the correct one, the one beside fuel injector driver side, all the other crap is plugged up

Then I don't think thats at all a problem.

If your engine light is on, check your codes. The code may shed some light.

[QWKSNKE]

If your engine light is on, check your codes. The code may shed some light.

:werd:

My cobra did that with the 'b' cam before it was tuned with a custom chip. But my check engine light never came on. It would just surge at idle and would not idle at all with the a/c on.

[Disney Lincoln]

If you haev messed with the idle set screw, then the TPS voltage is off. But that's not the issue right now.

Do this.....
Unhook the battery for a minute and step on the brake pedal to discharge voltage.
Get the car to operating temperature. Then unhook the connector from the IAB. Start the car. If the car doesnt want to idle, turn in the idle set screw until it does idle. Then you can set the TPS, set idle this way to about 800 rpm. If you haev to turn the set screw in more than TWO full turns from fully closed, then remove the TB and drill a small hole in the blade and start over. Once you haev it idling with the IAB unhooked, then you can set the TPS to .99 volts and make sure everything is good. Then you can reconnect the IAB and all will be well with the idle.

If it still acts stupd. You should try rotating the MAF meter 90* at a time until it improves.

Pull codes for the CEL. Fix any problems with that before you try to fix anything else.

Set base timing to 10* and FP to 39psi.

Adjust those at the track or on a dyno.

[93Cobra#2771]

My first vote - clean the sensing wires on your MAF. I suspect they may be oil contaminated. Clean them with CRC electrical contact cleaner (no touching) until they are nice and shiney.

[coupe]

First...It's not the cam.

Second: YES!!! You need to get your coolant temp sensor hooked back up. The computer NEEDS this for operations at cold-startup. Even if you want to run an aftermarket; hook it up.

[93Cobra#2771]

Without the ECT your engine may be running in open loop constantly which may be the reason for the problems.
Running without the ECT will not cause you to run open loop - it will give you a check engine light, but you will still go into closed loop...

On fox bodies, anyway. I assume he is a fox body by his avatar...

[Italian LX]

Running without the ECT will not cause you to run open loop - it will give you a check engine light, but you will still go into closed loop...

On fox bodies, anyway. I assume he is a fox body by his avatar...
:agree:

OL start-up is a function of time; not ECT.

[Italian LX]

Do you have a list of your mods? A picture of your current engine compartment would be helpful too.

Also, what have you deleted (EGR, purge canister, etc.)?

[93Cobra#2771]

Do you have a list of your mods? A picture of your current engine compartment would be helpful too.

Also, what have you deleted (EGR, purge canister, etc.)?
:werd:

[ujslost]

ok as far as the water sensor let me specify, i didnt remove the one on the metal heater hosing, that attatches to the intake, i removed the one on the drivers side just right of the dist.
I have no idea how to run the codes. this is an 89 gt
mods are as follows
76mm c&l mass air meter cali to 24lb injectors, 24lb injectors, fuel pressure set to 40-42 psi. typhoon intake, trickflow stage 1 camshaft, e7 heads shaved .040 with 1.94/1.60 valves, 1.6,1.7 roller rockers, 355 gear, t5 tranny, deleted smog and clutch fan. long tube headers , x pipe, borlas , timing 15*. 65mm tb and spacer. egr has the vaccum plugged off, but the electronics are plugged up still, never had a problem with this.

In reference to the IAB, if im thinking correct, I call that the IAC? Idel air control, 5 inch cylinder type thing mounted on the front of the TB?

As soon as I find my digital voltmeter, i am gonna check the TPS, and mess with the throttle screw like disney said.

[93Cobra#2771]

The one on the metal heater line is the one the eec uses, the one in the intake is the one the gauge uses...

Yes, IAC is the cylinder you are speaking of...

[coupe]

...i removed the one on the drivers side just right of the dist.
.

Therein, sir, lies your problem.

Some EECIV assistance here please: Isn't the Coolant Temp Sensor very critical to startup and rich/lean conditions? It has always been the main sensor to "trick" into making the car run rich, lean, or whatnot before the all the chips hit the market... Plug it back in & see where you stand. Your combo sounds alot like mine.

:shrug:

[coupe]

...the one in the intake is the one the gauge uses...

Ahh. Then it wouldn't be a culprit.

Maybe that IAC just needs to be replaced. You can buy one at Advance Auto...try it..and return it if it's not the fix. :nice: I've done that. :yup: shhhh.

[Wicked]

:agree:

OL start-up is a function of time; not ECT.

Thats not what I meant. I meant that if the ECu does not have a coolant temp data it may go into a "limp" mode and use lookup tables.

And I'm sure there's more to entering closed loop then time, or ECT. But we've had this discussion before.

[Wicked]

ok as far as the water sensor let me specify, i didnt remove the one on the metal heater hosing, that attatches to the intake, i removed the one on the drivers side just right of the dist.


Some people don't read the whole thread. :jester:

Also, i don't see how the IAC would go bad from a cam swap.

[ujslost]

ok ok ok, adjusted the throttle screw till she idles around 900 rpm, and then set the tps to .99 volts. idleing anylower sounds like crap honestly, but its idleing good now

So now i want to know how to search codes and find out why the damn check engine light is on? I have to reasons this may or may not be happening.
1. Electrical plug that goes to the master cylinder isnt plugged in?
2. The hole in the intake tube where I had my nitrous jet isnt plugged, so now its getting unmetered air? ( think italianlx will know the answer to that one)

Also it smells rich, but the air/fuel guage says its running lean to stoich. Havent seen it hit the rich on the meter at all, even at high rpms. But smells rich.

[QWKSNKE]

yep your surging is from the hole where the nitrous nozzle use to be. Get that plugged up and it will cure your startup problem :nice:

[Wicked]

yep your surging is from the hole where the nitrous nozzle use to be. Get that plugged up and it will cure your startup problem :nice:

Yup yup,

You messing with your idle screw may be the cause of your check engine light due to TPS out of range.

[ujslost]

well its idleing great now, gonna go ahead and plug the nitrous hole though just to keep from sucking debris in the intake.

Still want to know how to run a code search because the check engine light is still on!!!!!!!!!!!!!

[QWKSNKE]

go to someone who has a scanner

[ujslost]

Like Vato Zone! where all the mexicans hangout?

[QWKSNKE]

Like Vato Zone! where all the mexicans hangout?


don't know if their scanner will hook up to our antiques. Worth a try though. You may have to go to a mechanic shop

[jwillburn119]

on scanning... since i have been there lately... it is OBD 1 so auto zone isnt gonna help you... at all... you have to find somebody with a scanner to obd 1... most osciliscopes have them... just go to a shop... if they do free runs... you are good... it cost me 50 dollars to use an oscilliscope... that is a system used for scanning older vehicles for problems

[Disney Lincoln]

Man, just get out a analog voltmeter and read the codes yourself. I think there is a how-to on the Corral.net somehwhere. Best bet it to just pull out the test port (pass side near the MAF) and take it to Autozone or Advanced Auto. They will check the older cars still if you dont haev a scanner or analog meter.

[Italian LX]

Man, just get out a analog voltmeter and read the codes yourself. I think there is a how-to on the Corral.net somehwhere. Best bet it to just pull out the test port (pass side near the MAF) and take it to Autozone or Advanced Auto. They will check the older cars still if you dont haev a scanner or analog meter.
Hell, you don't even need a meter; just jumper the test connector and count the CEL flashes.

[Disney Lincoln]

YES!!! even easier!!

[93Cobra#2771]

yep your surging is from the hole where the nitrous nozzle use to be. Get that plugged up and it will cure your startup problem :nice:

Yep. You, sir, had unmetered air (vacuum leak) causing all kinds of problems... :D

[ujslost]

Yep. You, sir, had unmetered air (vacuum leak) causing all kinds of problems...

UH idels fine now, and still I havent gotten around to plugging that Nitrous jet hole!

Ok When i was into gm vehicles i just plugged a paper clip into the ecc test port in 2 connectors that were side by side/
Now on this ford which 2 do i need to jump each other too?
And you are talking about the ecc connector located near the brake booster on the rear of the driverside strut tower correct?

[93Cobra#2771]

UH idels fine now, and still I havent gotten around to plugging that Nitrous jet hole!
Then you still have a small vacuum leak...