Rebuilt 454 engine (slightly modified) Rebuilt tranny - stalls out in gear at idle - help...

[454cid]

I think you mean IAC, which is idle air control. It's in the throttle body. I have mine out now as I'm going to he cleaning it, the tps, and the throttle body itself. I just have to convince myself that I want work in the garage on a cold rainy day (today).

 

[Kraig]

I think you mean IAC, which is idle air control. It's in the throttle body. I have mine out now as I'm going to he cleaning it, the tps, and the throttle body itself. I just have to convince myself that I want work in the garage on a cold rainy day (today).

Yes sir IAC...acronyms aren't a dyslexic's friend but I quick fixed the post I could edit. Thanks a ton.

 

[PlayingWithTBI]

Without knowing what you have in the engine, I don't think any mail order tune will be right. You should figure out a way to data log, tune, data log, tune, rinse and repeat.

 

[Kraig]

Without knowing what you have in the engine, I don't think any mail order tune will be right. You should figure out a way to data log, tune, data log, tune, rinse and repeat.

After talking with Black Bear and taking a year off from fiddling with the "big burb" as my wife calls it and buying a 71 Scamp, I'm finally getting back to this. The goal will be to rewire and pin it out for a 0411 computer then get Black Bear to put a best guess tune on the PCM then get the scan cable to collect the data so they can build a custom tune for it. It has been running fine for the last year but when it is hot out it struggles at idle. Hopefully I can have it ready to go for hunting season. Hopefully a proper tune will yield something more than 8mpg.

 

[Schurkey]

buying a 71 Scamp,

Leaning Tower of Power? Or 318?

I had a '67 Dart GT, and when that was totaled, a '75 Dart Sport. Both with LToP. The '67 was way more fun to drive. That was all decades ago, and I STILL have visions of hopping up a Slant Six. Must be drain bamage.

The goal will be to rewire and pin it out for a 0411 computer then get Black Bear to put a best guess tune on the PCM then get the scan cable to collect the data so they can build a custom tune for it. It has been running fine for the last year but when it is hot out it struggles at idle... ...Hopefully a proper tune will yield something more than 8mpg.

8 mpg seems kinda bad. Runs bad when warm. Does the coolant temp sensor and harness work properly?

What other diagnosis have you done? Fuel pressure test? The usual "tune-up" parts--cap, rotor, plug wires, plugs, fuel filter, air filter?

What are the misfire counts for each cylinder?

What is the cranking compression pressure for each cylinder?

Does the EGR work properly--and is it shut off at idle?

"I" would spend more time looking for other faults, before going computer-tuning crazy.

 

[Kraig]

Leaning Tower of Power? Or 318?

I had a '67 Dart GT, and when that was totaled, a '75 Dart Sport. Both with LToP. The '67 was way more fun to drive. That was all decades ago, and I STILL have visions of hopping up a Slant Six. Must be drain bamage.


8 mpg seems kinda bad. Runs bad when warm. Does the coolant temp sensor and harness work properly?

What other diagnosis have you done? Fuel pressure test? The usual "tune-up" parts--cap, rotor, plug wires, plugs, fuel filter, air filter?

What are the misfire counts for each cylinder?

What is the cranking compression pressure for each cylinder?

Does the EGR work properly--and is it shut off at idle?

"I" would spend more time looking for other faults, before going computer-tuning crazy.

The Scamp has a mild balanced & blueprinted 318 running roller rockers and some other goodies that I picked up. It is pushing just north of 300hp with a nice torque curve...as soon as I get the engine bay painted & the engine in there. I got lucky a guy I knew had built it for his 73 Cuda and then decided it needed serious power with a 440 & I didn't want to be pushing anything massive until I upgrade all of the suspension parts and brakes. BUT that's for the mopar forum .

You know I hadn't checked the coolant temp sensor & harness yet. I didn't even have it on my list to check yet. (it is there now) I caved a year or so ago and had a shop I trust do a complete once over on the "rebuilt" engine. The outcome was, yes it was rebuilt but someone screwed with the computer and put a tune in it for a more free breathing build than what was done. I'm assuming the folks that built it before me had more plans like some long tube headers and whatever would justify the huge injectors they had put in that made it smell like gas all the time. I'm at the point where the shop got it running good enough to be reliable but it runs rich most of the time due to the tune and the 8mpg is kind of a side effect. The good news is I get 8mpg if I'm running empty or if I'm running with a car trailer behind me like when I brought the scamp home...so the engine just isn't working that hard...it's just tuned that bad. Once I get the 411 computer wired in and tuned I'll bet I get closer to 12mpg at least. We will see. I just wanted to update the thread to reflect where I was at, even if I took a year off from playing with the "big burb".

 

[Hipster]

The Scamp has a mild balanced & blueprinted 318 running roller rockers and some other goodies that I picked up. It is pushing just north of 300hp with a nice torque curve...as soon as I get the engine bay painted & the engine in there. I got lucky a guy I knew had built it for his 73 Cuda and then decided it needed serious power with a 440 & I didn't want to be pushing anything massive until I upgrade all of the suspension parts and brakes. BUT that's for the mopar forum .

You know I hadn't checked the coolant temp sensor & harness yet. I didn't even have it on my list to check yet. (it is there now) I caved a year or so ago and had a shop I trust do a complete once over on the "rebuilt" engine. The outcome was, yes it was rebuilt but someone screwed with the computer and put a tune in it for a more free breathing build than what was done. I'm assuming the folks that built it before me had more plans like some long tube headers and whatever would justify the huge injectors they had put in that made it smell like gas all the time. I'm at the point where the shop got it running good enough to be reliable but it runs rich most of the time due to the tune and the 8mpg is kind of a side effect. The good news is I get 8mpg if I'm running empty or if I'm running with a car trailer behind me like when I brought the scamp home...so the engine just isn't working that hard...it's just tuned that bad. Once I get the 411 computer wired in and tuned I'll bet I get closer to 12mpg at least. We will see. I just wanted to update the thread to reflect where I was at, even if I took a year off from playing with the "big burb".

Abodiesonly is where a couple of us hang out.

 

[Hipster]

Just going to toss this but sure you're not fighting a "too tight" converter with the wanting to idle issues?

 

[Kraig]

Abodiesonly is where a couple of us hang out.

You might have seen a few posts over there from me then. I feel much better knowing I'm not the only Mopar guy that secretly drives Chevy's too. Personally I'm an equal opportunity brand kind of car guy. I grew up with Fords, Had about 15 Mopars, then when I moved to GA ended up with Chevy's by fluke & didn't hate them...but I really do like mopar for my 60s-70s muscle car fix.

I don't think I'm fighting a tight torque converter because the tranny is a brand new GM Goodwrench put in by the guy that's done my tranny work for 18 years. He is real good but doesn't build the big trannies because the parts add up to quick, so I went with his recommendation of OEM.