Quote:

---

OK, well i've never had to deal with an issue like this before, so i'd like some ideas here.

Here's the issue, 69 charger r/t with a 440/727/8 3/4 with 3.23's, all stock motor except for mopar ele ignition, eddy CH4B intake, and eddy 1411 750 carb. when i floor it in, on the down shift it pulls hard to about 3600rpm, and then all of a sudden looses power, and almost stumbles/flutters without making power. Sometimes it does it, and sometimes not. It's really hard to describe it, but it's just like someone pulled a plug out while it was running, kinda missing and not making power. Not at insane high rpms, just on lets say a 40mph kickdown, then all of a sudden it just boggs.

---

What are you running for ignition? Orange box?
What kind of fuel pump?
Sounds to me like it could be either weak spark or weak fuel pressure.

Quote:

---

What are you running for ignition? Orange box?
What kind of fuel pump?
Sounds to me like it could be either weak spark or weak fuel pressure.

---

chrome ign box, i have a orange box i might try with the original kit. Fuel pump is stock, to be honest i did'nt check the fuel pressure, but i think it should be fine. It does'nt feel like a fuel issue, since you can back off, and then floor it again and it's fine. It's instant, like someone hit a switch, not like a random, fuel starvation issue, i've had those before, but this is different. ???

Quote:

---

Well... check out my latest post entitled:

UPDATE** Converting to the MSD 6A from MP ECU... My 340 acts the same way!

Maybe you and I have the same problem...

Question: Is this a recent/new problem or did you make several changes that could be the linked to the cause?

Tim...

---

i had a stalling problem, where the car would just shut off when driving, i changed the ballast resistor and the ign ecu (from orange to chrome). that solved that issue, and i was mainly sorting out the car so i really did'nt floor it until i just changed the original exhaust out for a TTi 2.5" and went back to HP original manifolds from some log 70's manifolds. I was afraid to floor it with the original exhaust, since there were alot of leaks, and it was hanging on by coat hanger wires!!!! Now that i've gone thru the whole car (even finding a loose engine mount!!!) i started driving it harder, and now noticing the problem. I might try the orange ecu, i think my stalling problem was the ballast resistor since it was cracked. It does not do it in high gear, only on a down shift when it starts going into the upper rpms, at about 3600rpms, then it just falls on it's face and puts your head into the windshield. I'm not thinking it's a fuel issue since it does'nt do it when your in high gear, at lower rpms. It's instant, like someone hit a switch, if you back off a little, then hit it again it's fine most of the time, almost feels like the seccondaries are just slamming shut.

Quote:

---

Had the same problem years ago on the Road Runner. It would run all day just fine, but when you drove it like it was meant to be driven, it would set you back in the seats and then all of a sudden it would just give up. Turned out to be that the fuel pump push rod was worn and it would not pump enough fuel under heavy acceleration . Replace the push rod and all is ok. Thanks - 69rrvert

---

i would agree, but the one thing is that if you floor it at 65mph+, without kicking down, it's fine right to where you just get scarred? i'd think that if the fuel pump could keep up with that, then it could keep up in a lower gear just higher rpm's. ???

One thing that makes me think it's not a fuel issue, is that it's instant, not like it slowly starves for fuel, but just an instant drop in power, motor boggs/surges, like it instantly runs on 4cyl's, does it about 60% of the time. but when it works it works, pulls right to 5000rpms or so and shifts, no issues.??? this one has me stumped.

Quote:

---

My first guess would have been fuel, until your reply about seeing 110. That rules out a fuel issue for the most part. That means elecrtical. My advise is the same song; check/fix grounds. concentrate on the engine and module grounds, but check them all. Do that first, then to see if it's an ignition problem, see if you can connect a timing light so you can see it and drive. Take it out and try to get it to mess up. That should at least let you see if it's spark related.

---

Actually, the part about connecting the timing light seems like a GREAT idea! This should indicate whether the ignition is cutting out or not. I may do the same on my 340!

Quote:

---

Quote:

---

My first guess would have been fuel, until your reply about seeing 110. That rules out a fuel issue for the most part. That means elecrtical. My advise is the same song; check/fix grounds. concentrate on the engine and module grounds, but check them all. Do that first, then to see if it's an ignition problem, see if you can connect a timing light so you can see it and drive. Take it out and try to get it to mess up. That should at least let you see if it's spark related.

---

Actually, the part about connecting the timing light seems like a GREAT idea! This should indicate whether the ignition is cutting out or not. I may do the same on my 340!

---

my guess is ignition as well, since every fuel issue on any car i've ever had the problem on was not so on/off instant. This problem happens like clockwork, everytime at the same time, it's hard to look at the tach while stomping it, but it's allways at the same moment. I'm also not leaning to a bad ground, since i've grounded the crap out of everything, the ecu is grounded by the mounting screws and i added a ground wire to a very good source, so that can't be the issue. I have good power to the coil, and the ecu, so that can't be the issue either. I'm starting to suspect the ecu, i'll try the orange box and see what it does and report back.

however keep the ideas comming....

Quote:

---

As in my previous post, I see several people saying fuel. It may not be a bad idea to spend the 30 minutes to check the push rod or fuel pump. I am not sure of the correct length, but I am sure that someone on here does. Don't do like I did last year. Do you remember the "383 sounds like a diesel" thread that I had? Right off the bat, everyone was saying that it was a timing problem, but I knew that it was not because I personally seen the timing marks were lined up when the timing chain was installed. To make a long story short, after much denial on the timing issue and about $500.00 later, I finally popped the timing cover and discovered that I used the wrong timing mark on the crank gear. It was about 4 teeth off. Spent $20.00 on a new timing gasket set and she runs like a top. Lesson learned . Thanks - 69rrvert

---

I'm not ruling out a fuel issue as of yet, but my gut tells me it's something else, as i said my symptoms do not point to a fuel pump, since a hard pull WOT from 65mph to 110mph is no problem, not even a miss. It's just on a kickdown. I would think that fuel is not a problem if the car can haul up to 110mph no issues???? The problem is instant, not like every fuel issue i had before where it was not as instant. It's hard to explain, but the best way i can explain it is with this situation: Driving at 50mph, floor it, kicks down, 2 secs later when it hits about 3600rpm, instant half power; back off so it shifts into 3rd, then kickdown again, and it's fine (usualy), and will pull hard until the 3rd shift comming in about 60mph.????