99 5.4l low rpm/low speed cruising engine loping, surging

[jchopo01]

I picked up a nice 99 Expedition for cheap with a blown 5.4. I swapped in a 2004 2 valve. I used my aluminum intake as the plastic one had blown up. Truck had been in an accident. Assuming it backfired on impact? Anyways I had to remove a chuck of plastic from one cylinder but I didn't see any damage with an inspection camera other than the plug had been smashed. New intake gaskets and what not. Runs good but when cruising from like 25-50mph it surges/lopes. Bad sometimes. Had a bad O2 sensor and thought that was it. Replaced that. Helps with overall running but didn't fix it. Has full power when I get on it. How the idiot that owned this that blew the motor had a dry nos system on it I think. Hole drilled through the air box to the mass air sensor. Would the computer having a custom tune cause the loping/surging? I put premium in and octane booster but doesn't really help much. Also idles @ 900 rpm, 700 in gear. No CEL. Any ideas? Going to check fuel pressure today hopefully but seeing it runs good at high rpms I believe its fine.

 

[american steel]

I picked up a nice 99 Expedition for cheap with a blown 5.4. I swapped in a 2004 2 valve. I used my aluminum intake as the plastic one had blown up. Truck had been in an accident. Assuming it backfired on impact? Anyways I had to remove a chuck of plastic from one cylinder but I didn't see any damage with an inspection camera other than the plug had been smashed. New intake gaskets and what not. Runs good but when cruising from like 25-50mph it surges/lopes. Bad sometimes. Had a bad O2 sensor and thought that was it. Replaced that. Helps with overall running but didn't fix it. Has full power when I get on it. How the idiot that owned this that blew the motor had a dry nos system on it I think. Hole drilled through the air box to the mass air sensor. Would the computer having a custom tune cause the loping/surging? I put premium in and octane booster but doesn't really help much. Also idles @ 900 rpm, 700 in gear. No CEL. Any ideas? Going to check fuel pressure today hopefully but seeing it runs good at high rpms I believe its fine.

you swapped an 04 in your expedition that might be the problem there but I might be wrong, have a ford shop tuner check your PCM try and replace the MAF sensor. also I would check all of the cylinders with a baroscope or camera what ever people call them.
there might be something wrong one your pistons or combustion chambers. there's a few possibilities there.
a bad PCV rubber hose will also do this. check all of your vacuum lines.
a bad timing chain is also known to cause this issue. ive seen several of the 2valve motors do this.
bad fuel filter or pump?
are you in 4 wheel drive?
if it is 4 wheel drive are the front and back tires the same size?
IAC valve?
take the air intake tube off the throttlebody and look at the throttle blade look at the carbon build up!
I don't know about a tune doing that but again check with a ford shop tuner mustang tuners will do this for you every state im sure has one.

 

[jchopo01]

you swapped an 04 in your expedition that might be the problem there but I might be wrong, have a ford shop tuner check your PCM try and replace the MAF sensor. also I would check all of the cylinders with a baroscope or camera what ever people call them.
there might be something wrong one your pistons or combustion chambers. there's a few possibilities there.
a bad PCV rubber hose will also do this. check all of your vacuum lines.
a bad timing chain is also known to cause this issue. ive seen several of the 2valve motors do this.
bad fuel filter or pump?
are you in 4 wheel drive?
if it is 4 wheel drive are the front and back tires the same size?
IAC valve?
take the air intake tube off the throttlebody and look at the throttle blade look at the carbon build up!
I don't know about a tune doing Idles but again check with a ford shop tuner mustang tuners will do this for you every state im sure has one.

I checked the cylinders. I tore the whole motor down to the heads. I left them on. Everything was cleaned spotless including the throttle body. No vacuum leaks from what I've heard or checked, I mean not sure if starting fluid is the best test but everything seemed good when I put it all together. Timing was correct and chains were taught and all seemed right. I just plugged in my tester today, all seems well with MAF and its been cleaned. But I had a pending P0401. The one egr pressure hose was pretty rough so I replaced the pair, checked egr function and put it back together. Cleared all out and still doing it. AWD/4x4 and all is right in that manner. Idle should be @750 roughly correct? Would the IAC sticking open cause the stumble/lope with throttle? It would seem it shouldn't as the air is accounted for correct? Checking fuel pressure later today. Filter has been replaced.

 

[american steel]

I checked the cylinders. I tore the whole motor down to the heads. I left them on. Everything was cleaned spotless including the throttle body. No vacuum leaks from what I've heard or checked, I mean not sure if starting fluid is the best test but everything seemed good when I put it all together. Timing was correct and chains were taught and all seemed right. I just plugged in my tester today, all seems well with MAF and its been cleaned. But I had a pending P0401. The one egr pressure hose was pretty rough so I replaced the pair, checked egr function and put it back together. Cleared all out and still doing it. AWD/4x4 and all is right in that manner. Idle should be @750 roughly correct? Would the IAC sticking open cause the stumble/lope with throttle? It would seem it shouldn't as the air is accounted for correct? Checking fuel pressure later today. Filter has been replaced.

you tore the motor down to the heads meaning you didn't take the heads off right?
if you didn't and you think a NOS kit was used on this motor there might be a problem with one or more combustion chamebrs. its a possibility
an IAC valve will make the engine stumble and/or when it gets more clogged at times from start up or when accelerating from a stop the engine will want to rev up and keep revving. again another possibility.
EGR systems in this motor will cause a stumble and or poor idle. at 700RPM these engines idle in park.

 

[jchopo01]

The old engine had NOS I think. Not the engine I put in. Just wondered if maybe the idiot tuned it and that's causing problems. I ran premium and no change. EGR cleared up, valve was cleaned and tested when I put the motor in. I put new exhaust pressure hoses on as one was rough. Code is gone but still having the stumbling. My idle is at 900-950 rpms. Checked again for a vacuum leak but notta. Fuel pressure is 34psi koer/koeo. 38psi on accel. Jumps about ten with regulator unhooked. Fuel trim levels look okay I think. Bank 1 LT around 7.5, bank 2 Lt around 4.6. I'll pull my IAC and check it out. Highway and such it runs great. Seems like full power and all but in town cruising is crap. Idle is smooth and doesn't fluctuate.

 

[american steel]

The old engine had NOS I think. Not the engine I put in. Just wondered if maybe the idiot tuned it and that's causing problems. I ran premium and no change. EGR cleared up, valve was cleaned and tested when I put the motor in. I put new exhaust pressure hoses on as one was rough. Code is gone but still having the stumbling. My idle is at 900-950 rpms. Checked again for a vacuum leak but notta. Fuel pressure is 34psi koer/koeo. 38psi on accel. Jumps about ten with regulator unhooked. Fuel trim levels look okay I think. Bank 1 LT around 7.5, bank 2 Lt around 4.6. I'll pull my IAC and check it out. Highway and such it runs great. Seems like full power and all but in town cruising is crap. Idle is smooth and doesn't fluctuate.

I read it wrong then.
your engine should idle at 700RPM park neutral or in gear.
I have never heard or seen any issue like this one, my tuner is on vacation otherwise I would ask him if he knew what would be the root of this for you.
I swap these processors in older fords all the time and I have never come across this.
if you suspect NOS was used on this vehicle chances are there was a tune put on it, a crappy one at that.
pull the IAC and look at your MAF sensor, this is seeming to me like a PCM problem or sensor problem.
and these processors RARELY go bad

 

[jchopo01]

Yeah I actually doubt a tune was put on, putting NoS on a stock engine is a poor choice I think, especially at 190k miles. I'm just assuming someone did because when I cleaned the MaF I found a hole drilled up through the bottom to the maf and I guess dry systems are installed that way.I'm gonna double check vacuum leaks. Thinking swapping COPs out and see of that helps but seeing it doesn't misfire idle or high RPMs I have my doubt's. I used the 2004 fuel rail, injectors, and fuel regulator btw. Also the 04 motor didn't have egr. I installed EGR on it since I used my intake. Should I not have done that? I don't know what changed to not use egr on a 2 valve.

 

[american steel]

Yeah I actually doubt a tune was put on, putting NoS on a stock engine is a poor choice I think, especially at 190k miles. I'm just assuming someone did because when I cleaned the MaF I found a hole drilled up through the bottom to the maf and I guess dry systems are installed that way.I'm gonna double check vacuum leaks. Thinking swapping COPs out and see of that helps but seeing it doesn't misfire idle or high RPMs I have my doubt's. I used the 2004 fuel rail, injectors, and fuel regulator btw. Also the 04 motor didn't have egr. I installed EGR on it since I used my intake. Should I not have done that? I don't know what changed to not use egr on a 2 valve.

currently I cant think what replaced the EGR set up. I don't look at these vehicle's every day.
I done an 04 a few years back for a guy I know he spent 90k on the damn thing, ill be seeing him today while im at his house ill look at his engine and see what's up.
and I don't see how adding factory EGR to the newer motor will effect anything. its present on your PCM so that should not be a problem.

 

[stamp11127]

Ford shop manual still shows an egr setup on the 2004's.

 

[american steel]

I never did get the chance to look at his expedition. this is a weird one ill talk to my shop tuner on Tuesday.

 

[jchopo01]

EGRs were deleted starting in 2000 I think, just a few made without at first and progressed until something like 2007 on the 2 valve where most had no EGR. I just don't understand how the heck they just eliminate them? If its just a programming thing or what... I though can phasers were the reason and those are the 3 valve though.

Anyways maybe I'll the vaccum on the egr and see what happens. I changed the PCV valve thinking since the other intake blew up it was bad. I used the twist in kind the 2004 had. Assuming a PCV valve is a PcV valve that it shouldn't matter if its the $3 one from 1999 or the 2004 one that twist and locks in and cost $22 right? Idle improved a little, down to 800rpms but still stumbles. Today now spring is coming and it was raining it seemed much worse, even when taking off with a heavy foot from stop sometimes it just fell flat on its face damn near stalling completely then coming back full power. I'm going to change out the TPS and maybe the MAF? Maybe it really is going bad? Especially with humidity? Stumbling bad off the line seems to help with ideas now. Just everything data wise in the tester seems right but it isn't realtime so who knows.

 

[american steel]

my tuner told me that the PCM should be good no matter what tune is put on, the processor should not cause these issues, I would check with all of your sensors you brought the idle down now it should be at 700RPM seems like there is a vacuum/leak problem and or MAF but there's also a few more variables here at play with your engine. my 02 has EGR just like the 98 I had. the 3vavle motors used cam phasers, so no EGR there.
if your engine seems like it wants stall when coming to a stop and it continues to do this for a while your converter might be trying to lock up the trans. just to throw that out there.
ford continued to use the 2 valve heads for certain model F150s and I think XL SUV until 08. I think those might have a different system than what 97-02 uses.

 

[jchopo01]

Not the torque converter. It just stumbled when I went to take off. So I was thinking today after I was driving in the nasty snow/sleet and she was bucking pretty good cruising through town that maybe I should pull the egr vacuum off. So I did and plugged it. Hasn't stumbled since. I'll test it more tomorrow and over the week to see it that really is it. I know there are non-egr two valve versions since like 2000 or something. I just don't know why, and what changed. I was just putting the egr on to avoid a CEL light but apparently I might have screwed myself. The valve was functioning right I know that. The heads were a different casting than the 99 ones of course. Maybe it compensated for egr? And then I was putting exhaust gases in when they weren't needed?

 

[american steel]

dude honestly I don't remember what changes in the 3rd gen 2 valve there were as far as castings, I deal with so many engines on a daily basis its hard for me to keep up.
like I said its something small, a sensor or EGR related. keep this thread posted.