OK, got the car running. But it doesnt run well.

[5.0Torx]

Hey all

Spent a week getting GT40Ps and exploder intake on my car. I bought a 70mm TB and EGR spacer off ebay. I have a C&L 73mm MAM.

The car will fire right up but it takes a second for the idle to settle out. Itll dip down to about 550 rpm and then settle out to a steady 700-800. It also seemed a little soft power-wise, so i thought it was the C&L. I had tried the C&L before on the stock top end and it felt soft there too.

Switching back to the stock 55 seems to have made a slight difference, but the symptoms are very much the same. I know im really pushing the stock tune out of bounds with all the new stuff, but i figured choking the engine down with the stock MAM wouldve helped more than it did.

Could this be as simple as a new MAM?

Also, ive been thinking about getting a new fuel pump. Summit has one a 45 psi, 155 lph unit for $76. Think thats alright?

TIA

 

[MikeROD16]

try some 24lb injectors and getting ur MAF sensor calibrated to it. That might help. and i would go for a 255lh pump and an adjustable FPR.

 

[strtrcr50]

try some 24lb injectors and getting ur MAF sensor calibrated to it. That might help. and i would go for a 255lh pump and an adjustable FPR.

His setup really shouldn't need 24 lb injectors or a 255 pump. If he is changing the pump anyway, yes, put on the 255. Any codes? What's your timing set at?

 

[Dino Dino Bambino]

If you still have the stock fuel pump, you definitely need to upgrade it. Otherwise it seems that your engine computer just needs time for adaptive learning of your new mods, especially if the C&L MAF you're using is correctly calibrated for 19lb injectors.

 

[jrichker]

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical

If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[MikeROD16]

he's basically running a cobra engine now, but with a bigger mass air meter and tb. he should have 24 lbs to run better. cobras didnt have them for no reason.

 

[strtrcr50]

he's basically running a cobra engine now, but with a bigger mass air meter and tb. he should have 24 lbs to run better. cobras didnt have them for no reason.

I personally would address the problem before I did upgrades. 19's should support what he's running. To the best of my knowledge, the explorer that the heads and intake came off of had either 19s or 17s, didn't it? This reminds me of the fuel pump eccentric thread.

 

[Maryland Stang]

With the few mods he has the car should start and idle just like factory. All he did was switch to a different set of Ford heads and intake. He didn't say anything about porting or changing the cam. His car may pull a little harder but he'll see not much more than that. At this point his original injectors and fuel pump should still be sufficient.

If the car doesn't run right with the original MAM then he doesn't have a problem with the C&L. Do like jrichker said and pull the codes.

Also if it ran right before the intake and heads then it should run right after you installed them. You didn't really make that many changes. I would also spend some time making sure all of the electrical connections are clean and tight. Also make sure you reinstalled all of the engine grounds correctly, clean and tight. There are 3 ground connections to the engine. 2 on the front and one on the back of the driver side cylinder head.

 

[66sprint6]

I just swapped some heads myself and am chasing some problems as well...Go thry the suging idle checklist that Jricher posted religiously! Its solved a TON of problems for me...still got a few little issues but I think Im on the right track. Good luck!!!
Matt

 

[5.0Torx]

When I first plugged in the battery for the first time, i tried pulling codes before firing the engine, just in case.

I came up with 21, 23, and 24.

Also i feel it worth mentioning that i managed to stretch the stock intake tube over the 70mm TB. It took some time and some WD40 but i got it. Also running the stock airbox with a newly cleaned and reoiled K&N panel filter.

I know one of the codes is for the TPS voltage higher than expected. Its at .94 volts. I can double check that but i thought that was right where it should be at. Theres no throttle hesitation or anything. It just feels soft. Like i wasted a week fo my time getting all these cool parts on the engine for nothing. Feels weaker than with the stock top end.

Cam is at OEM timing. Not advanced or retarded. New chain though.

Plugs are gapped .050 +/- .003ish. Autolite 104s.

New fuel filter.

Car ran great, put down 207/274 and got high 20s, low 30s highway mpg with the stock top end. I drove it 200 miles with the new stuff and didnt use fifth gear much and managed 22 mpg. Im sure if i had used fifth more i wouldve done better. Changed the oil after 200 miles. Mobil 1 synth. FL1A filter.

 

[5.0Torx]

Oh and timing is at about 10 degrees BTDC. I read on here that youre supposed to unplug the SPOUT connector, which i figured was the electrical plug, but the car didnt want to start without it. With it plugged in the timing jumped around 10 degrees +/- 1 degree. I tightened it down there and am on 93 octane for now because i dont want to blow anything up. Im willing to time it to run on premium, but would be interested in retarding it a bit for regular. I know the Ps up the compression so i realize that might not be an option.

 

[66sprint6]

Theres a good indication as to why she's weak!!! Start the car then pull the SPOUT while its running, it should stay runnin. If not, bump up your idle some for the time being. Bump that timing UP!!! My car LOVES timing, Ill run around on 18* all day long on 93 octane but every car is different so try 14* or so and go from there listening for pinging. Set the timing, put the spout back in. Re-set the idle using Jricher's directions and then enjoy!!!
Matt

 

[strtrcr50]

I came up with 21, 23, and 24.

Code 21-ECT out of self test range .3 to 3.7 volts
Code 23-Closed throttle TPS voltage higher or lower than expected
Code 24-ACT sensor out of self test range .3 to 3.7 volts

These 3 sensors all share the same ground along with the map sensor and the egr position sensor. I'd prob start by checking the black/white wire.
When you tested the TPS, were you probing the hot wire and grounding at the battery/random bolt, or were you grounding on the black/white wire?

 

[strtrcr50]

Theres a good indication as to why she's weak!!! Start the car then pull the SPOUT while its running, it should stay runnin. If not, bump up your idle some for the time being. Bump that timing UP!!! My car LOVES timing, Ill run around on 18* all day long on 93 octane but every car is different so try 14* or so and go from there listening for pinging. Set the timing, put the spout back in. Re-set the idle using Jricher's directions and then enjoy!!!
Matt

+1. Timing is to be set with the spout out. IIRC, my car usually bumps the timing about 6 degrees with the spout in while idling. I think I put mine to 14 base timing.

 

[5.0Torx]

thank you my fellow mustang peeps!

i didnt want to start it with it in and unplug to time it and plug it back in for fear of frying the computer or something. you guys are telling me thats ok? im not gonna see sparks fly once i plugg it basck in?

i tested the tps againt the engine. ill recheck it with its ground.

where do i find "the" black/white wire?

 

[5.0Torx]

oh i also feel it worth mentioning i removed all the smog stuff. the pump is still on because i didnt have time to measure out a new belt length to eliminate it. i plugged all the hoses. my mechanical vacuum gauge holds steady at 19 in Hg at idle

 

[strtrcr50]

It will be one of the wires coming out of the 3 sensors you have codes on.

 

[mob]

Your car should start with the spout out. Not questioning your intelligence here with a dumb question but you did unplug the little connector in the middle of the wire and not the actual plug from the dizzy right?

 

[5.0Torx]

Your car should start with the spout out. Not questioning your intelligence here with a dumb question but you did unplug the little connector in the middle of the wire and not the actual plug from the dizzy right?

......................................................................

 

[strtrcr50]

Well, did that get you running right??