2004 SVT lightning bogging at cruise and mild accel

[isonews]

guys

Imy 2004 lightning is stock, I am getting a bog when I am accelerating lightly at the 2-3 shift. also at 70mph cruise if I'm going slightly uphill I get a bog.

This bog feels like the car is about to stall and then comes back.

Any thoughts ? I'm thinking coil on plug, plugs ? Torque converter ?

 

[isonews]

Guys it feels like a really hard shift when cruising uphill .... any thoughts ?

 

[Dusten]

Have you done any work recently?
Hard shifts and light throttle issues could be an issue with the throttle position sensor.
I'd check the voltage on that before you start throwing parts at it. Coils aren't common. When were the plugs last replaced?

 

[pierce88]

Sell it

 

[isonews]

I imagine the plugs are the original plugs with 80k on them. No modification work has been done on the truck.

I'm almost positive it's the coils, seems to start to die out at idle when it gets hot..... If not that, has to be the TPS...

 

[Dusten]

I imagine the plugs are the original plugs with 80k on them. No modification work has been done on the truck.

I'm almost positive it's the coils, seems to start to die out at idle when it gets hot..... If not that, has to be the TPS...

Coils are expensive. Coil failures are uncommon.
You can test the tps for free.

Plugs are cheap. Go that route first. I've been around these trucks for years. I'm just trying to help.

 

[isonews]

I went with the cheap Chinese coils on Amazon with a new set of oem autolite plugs. I installed the coils and plugs last night. I also cleaned the IAC

issue is still unresolved ! This morning it stalled out at a light and would not restart, I had to rev it up in park and then finally it was ok. When it started accelerating it was surging Pretty aggressively and almost dying out.

Im going to check TPS with my scanner , I've also got an new IAC sensor on order.

Thanks for the suggestions, keep them coming !

 

[isonews]

Sell it

Hah , and replace it with what... one of those new ugly lightnings

 

[Dusten]

I went with the cheap Chinese coils on Amazon with a new set of oem autolite plugs. I installed the coils and plugs last night. I also cleaned the IAC

issue is still unresolved ! This morning it stalled out at a light and would not restart, I had to rev it up in park and then finally it was ok. When it started accelerating it was surging Pretty aggressively and almost dying out.

Im going to check TPS with my scanner , I've also got an new IAC sensor on order.

Thanks for the suggestions, keep them coming !

You need to check fuel pressure too

 

[isonews]

It was 30 at idle, upon revving at idle it goes up to 40. Then all of a sudden it started stumbling at went down to 8 at idle....

I'm guessing fuel filter? Hopefully not the pump(s)

 

[Dusten]

It was 30 at idle, upon revving at idle it goes up to 40. Then all of a sudden it started stumbling at went down to 8 at idle....

I'm guessing fuel filter? Hopefully not the pump(s)

Could be pumps, relay, or the plastic y in the tank.

http://www.lightningrodder.com/forum/showthread.php?t=9648

 

[isonews]

Thanks Dusten, I changed out relays still same problem.

Guess it has to be pumps or the Y.
I was going to go with a full stock drop in unit(see link below), the truck just has stock tune, stock pulley, intake and exhaust. What do you guys recommend?


https://m.summitracing.com/parts/dfp-hp10192

 

[Dusten]

I recommend you pull the tank and look for issues before you buy more parts.

 

[ArkLightning]

Has the fuel filter ever been changed. Mine started missing and bucking a few years ago when trying to lightly accelerate. I installed a new fuel filter and it was fine. It's also relatively inexpensive.

I only put about 500 miles a year on my truck so fuel sits in it a long time. I recently had similar missing. bucking issues and suspected the gas had gone bad since the filter is only about 2 or 3 years old. I added fresh gas and loaded it up with gas drier and Seafoam and after a few miles it seems to be back to it's old self.

Missing at light throttle is a good indication of a coil pack or ignition wire issue (but NA on a Lightning). But you should get a code and cylinder set that you can pull up. Neither the bad filter or the bad gas has set a code on my truck.

 

[Dusten]

the thresh hold for a CEL for a misfire is so high, that you'll rarely see the code. I removed a coil and drove my truck a mile before the light was set.

 

[isonews]

Well guys

New coils, new plugs still same problem

I changed fuel filter still same problem

I got the full fuel pump assembly including the plastic Y replaced

I'm at the end of my patience with this truck

Help

 

[Dusten]

Well guys

New coils, new plugs still same problem

I changed fuel filter still same problem

I got the full fuel pump assembly including the plastic Y replaced

I'm at the end of my patience with this truck

Help

So you're still swapping parts with no trouble shooting. How's fuel pressure? Could be a bad resistor.

I told you coils weren't the issue.

 

[Dusten]

Can you get a video

 

[thatdude305]

They don't make new lightnings. It sounds like its time to either bring it to a dealer with a certified svt guy or find a reputable shop around you. You've spent all this time and money replacing stuff to no end. I just bring my whips to a shop for everything. It costs me a tiny bit more, but I have piece of mind

 

[isonews]

Dusten,
fuel pressure is in spec, it just dips sporadically...
unfortunately it will only happen about 2-3 times during a 100 mile drive. and it ONLY does it when it's hot (ie after 45 minutes of driving) So I might have to get a dash cam to get a video. Might not be a bad idea!

I usually never bring my car to a mechanic, try to do most things myself. But this issue seems a bit strange...

Thanks for the help guys.