Resolved Very Hard to Start/High Idle

T

TheCyborgSlayer

Member

Dec 4, 2023

6

2

13

Louisiana

Jan 13, 2024

#1

• Jan 13, 2024

• #1

I’m trying to run down the last issue I’m having so I can drive my car for the very first time.

It is very hard to start. It turns over fine, but I have to try for a minute or more before it eventually catches and runs. Once it’s running it runs smooth as butter, but the idle never falls down below 2200.

So far I tested the TPS and I get .92v at idle, as I open the throttle is smoothly increases to 4.8v at WOT.

I replaced the MAF and IAC with brand new OEM parts and the problem remains.

What else can cause this problem? EGR? I feel I’ve been able to rule out the usual suspects. I’m ready to finally drive this thing so hoping you guys can help me figure it out!

 

Y

Yel2002GTAuto

Active Member

Sep 26, 2022

233

26

38

Granit City, IL

Jan 14, 2024

#2

• Jan 14, 2024

• #2

There are a few things that can cause a high idle..
1. Bad TPS Sensor
2. Set screw moved for the Throttle Body Blade, you can take off the CAI at the TB and check to see if the Blade is closing all the way or stuck open, or blocked
3. Vacuum Leak
4. Tune (Usually if you have aftermarket products like CAI, TB, Plenum, or EGR Delete...

I would start with trouble shooting these first..

Ed

 

P

PSKSAM2

Founding Member

Feb 13, 2002

771

8

38

NJ

Jan 26, 2024

#3

• Jan 26, 2024

• #3

The starting issue makes me think fuel if it is cranking ok but takes a while to start. Simplest answer may be to change the fuel filter if you haven't in a while. I had some odd staring/hesitation issues when my pump started to go, should have done it sooner before I needed a tow.

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Admin Dude

Jan 4, 1985

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Jan 26, 2024

#4

• Jan 26, 2024

• #4

PSKSAM2 said:

The starting issue makes me think fuel if it is cranking ok but takes a while to start. Simplest answer may be to change the fuel filter if you haven't in a while. I had some odd staring/hesitation issues when my pump started to go, should have done it sooner before I needed a tow.

Click to expand...

Try this:

1. Cycle the key to the [On] position but do not start the car.
2. Wait 3 seconds.
3. Repeat steps 1 and 2, two more times.
4. Start the car and report back to us, what happens.

 

Y

Yel2002GTAuto

Active Member

Sep 26, 2022

233

26

38

Granit City, IL

Jan 29, 2024

#5

• Jan 29, 2024

• #5

yea, fuel filter or weak pump can cause this too...easy fix..any results yet?

 

T

TheCyborgSlayer

Member

Dec 4, 2023

6

2

13

Louisiana

Jan 30, 2024

#6

• Jan 30, 2024

• #6

I’ve done a good bit of troubleshooting this far. Testing spark, injectors, etc. I hooked Forscan up while trying to crank the engine over and the fuel pressure is all over the place.

The IAC did fix my idle issue. I never actually started the car after replacing it. When it was still hard to start I just assumed it didn’t fix it.

So I came to the conclusion that it is the fuel pump also. I have a new pump assembly in hand, I’ve just been busy with work and haven’t had a chance to install. I’m hoping this weekend I’ll be able to knock it out. I’m fairly certain that this will fix my starting issue.

 

Y

Yel2002GTAuto

Active Member

Sep 26, 2022

233

26

38

Granit City, IL

Jan 30, 2024

#7

• Jan 30, 2024

• #7

Sound right now...just ensure you replace the fuel filter at the same time...based on your feedback, I think you should be good..

ED

 

T

TheCyborgSlayer

Member

Dec 4, 2023

6

2

13

Louisiana

Feb 5, 2024

#8

• Feb 5, 2024

• #8

Finally had a day off of work so I was able to jump back on the stang. I dropped the tank and replaced the fuel pump and the car starts normally now.

 

Reactions: Noobz347

Y

Yel2002GTAuto

Active Member

Sep 26, 2022

233

26

38

Granit City, IL

Feb 5, 2024

#9

• Feb 5, 2024

• #9

Awesome to here..glad it was a simple fix!

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Admin Dude

Jan 4, 1985

43,033

21,207

234

Box behind Walmart

Feb 5, 2024

#10

• Feb 5, 2024

• #10

Wait... Dammit... OH, well.

 

Potomus Pete

I'm still waiting for the fully nude shots

5 Year Member

Mar 7, 2019

3,308

1,223

153

Sarasota Florida

Feb 5, 2024

#11

• Feb 5, 2024

• #11

So what now...Your driving the car for the second time. Whats up with it and some pictures if possible

 

P

PSKSAM2

Founding Member

Feb 13, 2002

771

8

38

NJ

Feb 6, 2024

#12

• Feb 6, 2024

• #12

TheCyborgSlayer said:

Finally had a day off of work so I was able to jump back on the stang. I dropped the tank and replaced the fuel pump and the car starts normally now.

Click to expand...

Nice work, that has to feel good!