View Full Version : Experienced V6 peeps, see inside.

10-26-2007, 09:02 PM
00 V6 Coupe. Auto.

Starts hard after sitting for an hour or more. When it finally does start, it idles slightly rough and has a bit of a shake to it.

Going down the road at any speeds theres an ever so slight hesitation, almost like a brake is hanging up for a split second.

Also seems to take a bit longer to shift gears than I'd normally like to see on an automatic car.

I've checked the coil and EGR valve (both perfect), and replaced air filter and plugs. No codes, no CEL, just rough running, hard starting, and a slight hesitation at steady speed.

Any ideas?

10-26-2007, 09:13 PM
The most obvious points remaining would be a clogged fuel filter, O2 sensors that are just starting to get tired, or a dirty MAF in my opinion. Beyond that I'd say TPS. The hesitation in gear shifts wouldn't be out of the question if the car isn't running right in general. The TPS was failing in one of my '89GT's and the car stalled out, didn't want to start, and shifted crazy - but didn't throw a code.

Good luck and let us know what you found...

10-26-2007, 10:15 PM
Is it loading up on fuel? Does the oil smell like fuel?

10-26-2007, 11:21 PM
mine shifts like that too you can floor it and theres like a second delay sometimes, not every time though.

10-27-2007, 03:11 AM
Can you check fuel pressure?

10-27-2007, 06:00 AM
dirty MAF, fuel filter, TPS or IAC.
Also check for vacuum leaks between the MAF and throttle body.
All vacuum lines are on & good?

10-27-2007, 04:15 PM
Maf cleaned, IAC clean and working fine. Oil is clean and fuel free , coolant nice and green and full. The fuel filter looks reasonably new, but who knows.

Tested the coil and got 13.7 across all 3 sets of poles, even tried replacing it just for S&G's, nada.

Just put on a CAI, did the same before and after install, made sure all pipe connections are sucka-free.

I dunno, ****'s got me baffled.

10-27-2007, 04:21 PM
well when I had a hard start after sitting was a fuel pump on the way out.

I have a spare used stock fuel pump in the basement

10-27-2007, 06:40 PM
Thats kind if what I was thinking too, like the thing isnt getting enough gas, or the check valve in the pump isnt holding pressure after shutdown.

If I do the pump, whats out there for upgrades?

10-27-2007, 07:17 PM
stock replacement or go to the 310 lph focus pump

10-27-2007, 08:23 PM
K. Just bought this one.


Figure it might not be the problem, but it's nice to have anyway.

10-28-2007, 07:17 AM
If that is the focus bucket & fuel level sender you will need only the pump which will just drop into your bucket assembly.

10-28-2007, 07:22 AM
lean issue for sure!

10-28-2007, 09:39 AM
If that is the focus bucket & fuel level sender you will need only the pump which will just drop into your bucket assembly.
Thats what I figured.

Should be here in a few days so on Thursday-ish I'll probably install it and some new 02's and see what it do.

10-28-2007, 09:54 AM
get motorcraft O2's. If you don't have a hookup Rockauto.com has decent prices

10-28-2007, 01:35 PM
I've got brand new Bosch 02's out of the 94 sitting here, looks like they cross-reference to the 99.

Whats the difference?

10-28-2007, 01:53 PM
From what we have found the motorcrafts work better. If you have those then give them a try.

10-28-2007, 03:07 PM
motorcraft work better..... from my own personal experience anyway.

10-31-2007, 08:15 PM

The o2's made zero difference, but the SVT Focus fuel pump did solve my hard starting issue.

The hesitation and less-than-perfect idle is still present though.

11-01-2007, 08:28 AM
Have you reset your TPS and the base idle yet?

11-01-2007, 09:00 AM

Just disconnect the battery for a while, i'd imagine, eh?

11-01-2007, 10:21 AM

Just disconnect the battery for a while, i'd imagine, eh?

No. The following links are for 8's, but you should still be able to apply the idle procedure with not problem and find plenty of useful diagnostic info in general from the second link

Base Idle Procedure (http://www.my5oh.com/forum/viewtopic.php?t=1078)

If that doesn't do it this link has loads of info on tracking down a surging idle. It might not be your exact symptom, but it may point you to something that may help. Lots of info in this thread

Surging Idle Checklist (http://forums.stangnet.com/showthread.php?t=698148)