Stalling

[John cheramie]

Ok so I bought a 2001 4.6 and it was stalling out when I accelerate fast I have replaced the MAF, IAC, TPS and all 8 coils... I am only getting o2 codes due to cutting the cats out and a p1000 code which it needs a drive cycle but when I clear the codes it does fine for a couple of stops and then it starts it again but if I feather the gas it dont do it as bad and it does not do it all the time??? Any help I am lost please

 

[docraymund]

It's either a dirty fuel filter or a weak fuel pump.

 

[hypercardriac]

Ok so I bought a 2001 4.6 and it was stalling out when I accelerate fast I have replaced the MAF, IAC, TPS and all 8 coils... I am only getting o2 codes due to cutting the cats out and a p1000 code which it needs a drive cycle but when I clear the codes it does fine for a couple of stops and then it starts it again but if I feather the gas it dont do it as bad and it does not do it all the time??? Any help I am lost please

If you’re going to run without cats, you may consider defoulers on the downstream (2nd) sensors to eliminate the o2 codes. The expensive method would be to have the module tuned to run without.

I would certainly consider the defoulers before going any further.

Checking fuel pressure, as well as vacuum leaks and IAC gasket, you should find your issue. Right now your o2 sensors are telling your motor all kinds of crazy shit and that needs to be handled first. Defoulers are extremely cheap and can be found on eBay for next to nothing on the dollar.. A single high flow cat on each side wouldn’t be a bad consideration either, if one had the extra dough to throw..


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[ats666]

If you’re going to run without cats, you may consider defoulers on the downstream (2nd) sensors to eliminate the o2 codes. The expensive method would be to have the module tuned to run without.

I would certainly consider the defoulers before going any further.

Checking fuel pressure, as well as vacuum leaks and IAC gasket, you should find your issue. Right now your o2 sensors are telling your motor all kinds of crazy shit and that needs to be handled first. Defoulers are extremely cheap and can be found on eBay for next to nothing on the dollar.. A single high flow cat on each side wouldn’t be a bad consideration either, if one had the extra dough to throw..


Sent from my iPhone using Tapatalk

Oxygen sensor spacers on this vintage of vehicles does nothing but stop the cat inefficiency code from coming up. Does not affect fuel trims or idle. The rear O2s are just there to make sure the cats are functioning.

Check fuel pressure and vaccum leaks (anything past the mass sensor).

IAC only comes into affect at idle, won't cause issues during hard acceleration.


Now to the OP.
What codes do you get after a full proper drive cycle?

 

[John cheramie]

As of now I just put another vapor purge valve canister on it... I pulled the codes and I am getting o2 sensor and a p1000 which is a ford drive cycle and also abs/rear wheel sensor and it has a mis fire on cylinder 3 also... But Since I put the new/used purge valve canister on it has only tried stalling/hesitate 1 time and thats it....

I guess my next question would be can the rear wheel sensor cause a stumble like that... And also when driving without cruise control when I let off the gas its like the throttle stays the same for an extra 3 seconds or so then it starts falling

 

[ats666]

Upstream or downstream O2 sensor?

Replace cyl #3 c.o.p.

 

[Bilsto]

Mine does something similar to that. If I slow down almost to a stop, then suddenly hit the gas, it will fall on it's face. It recovers without stalling, but it's really annoying because there are intersections where I have to do that. I do the same thing, kinda hit the gas pedal carefully. Since I know when it's going to do it, I can work around it. But it indeed is annoying! I replaced a bunch of sensors too, with no luck.

 

[John cheramie]

ok so i am still working on my ride i did a compression test and all had 125 but one it had 65 on the #3 cylinder... removed valve cover and noticed that my timing chain guide has broken and can move about an inch up and down... i will be performing a cylinder test tomarrow morning by pouring a very little oil on top of the half dead cylinder and test the compression if it goes up that means a ring has failed but if stay the same then i can move on to the valves but honestly i hope its just the timing... But on a real note what would my timing on my code reader be????? reading as far as numbers if i recall right it was around 24 on mine

 

[docraymund]

Only one cylinder is low, it could be a valve problem. You need to do a cylinder leak down test. And pull the front timing chain cover so you could check the timing marks.