I bought a 73 Cuda with a 5.7 swap. It has a Silver Sport 4L80E trans. Engine is stock, but has a LS throttle body to operate a traditional gas pedal. Has an EZ Tune computer controlling the engine. Runs and drives great, most of the time. Always starts and shifts into gear when cold. However, sometimes after a drive if the car is shut off, when started again will stall repeatedly when you try to put it in gear. Literally, you need to rev it up and bang it in gear or let it sit. Since it's happens sporadically doesn't seem like the tune can change. I'm not a tuner so where should I look? The tune, ICA, or a sensor.

you may need to recalibrate the TPS. make sure the motor is well warmed up to operating temp before you do any adjustments. This includes fuel tables I am not familiar with the EZ tune computer so i will have to do some research

you could have a bad O2 as well. are you getting any error codes? what can you tell us about this controller you are using? is this in addition to the factory ECU?

Take all that aftermarket and Blunder Motors JUNK out of there and put it to a Chrysler transmission with a Chrysler computer. Current and all future problems solved.

Otherwise, hire a Rocket Scientist, because that's what it's going to take to figure that mess out. Does it have Ford rear-end in it too?

Viperakron,

pay no attention to Grizzly.

Grizzly again please just add quality answers to the questions. he is legitimately asking for help.

Viperakron,

I am not really finding much on that programmer that you have. not sure what the budget is but there are a few other ways to go with this if you cant line it out. there are a lot of smart guys on this site that are willing to lend a hand

I'm just being realistic and am legitimately trying to help.

The OP is looking for reliability and this is the only way he's going to get it.

I'm looking for a modern car in a classic body. I've had dozens of # matching correctly restored Mopars. Love to work on them over the winter, but after I drive them 100 miles they are not road friendly and a PITA. Basically coffee tables to be trailered to shows or take a short drive to a cruise. I want to drive the car, not scream down the road at 3000 RPM @ 60 MPH getting 10MPG on 93 Oct gas.

Still have them but the resto mod is the way to enjoy the look with the convivences of a modern car. My problem is tuning and hi tech wiring. This car is 95% done and I drive it on long trips, with 22MPG, nice sound system I can hear, stops like a new car, turns like a new car. Grizzly don't fight the inevitable. Old muscle is easier to work on, not much fun to drive for very long.

Back to the topic. Car is tuned with EFI Source computer and a EZ Tune system for the trans (4L80E. I'm looking for a tuner here in NE Ohio to help. But I don't really think it's the tune, more like a sensor. Runs fine when started, after it gets warm (10 miles) and not every time, starts and idles but stalls going into gear. Let it sit for a while and works fine. What sensors could be affected by a heat soak?

Grizzly is right. If you want to get a GM hermaphrodite system to run you would probably have better luck on an LS forum, just don't tell em its a hemi. It is probably a computery issue not an issue with the actual chrysler stuff you are using.

Transmission is not the issue. it's in the engine sensors or tune. 4L80 is the go to trans for Mopars who don't want the hack the hell out of the floor. Bolts right in with different cross member.

The Gm transmission is on its own system and has zero effect on the engine management. I would have gone the GM trans route if I did not find a 518, the 518 at least where I am is very hard to find and I'm regretting it at the moment as a high stall lock up torque converter at the moment is not available.I have been waiting 2 months and they tell me they can't get parts. Too many people freak out about miss-matching brands.

I see the engine has megasquirt if its from efi source. The hot idle should be set by the idle screw on the throttle body. The IAC motor usually controls cold idle and a boost for the AC compressor.

You need a laptop and the tuner studio software and see whats going on with it. I only know the holley efi. It should work the same. If you could data log the stall you would be able to see what happened, the IAC should stop that from happening if it was set up right. I would not throw parts at it without knowing whats wrong.

When its hot unplugg the IAC motor and see where it idles, that will tell you how much its using it when hot, should be 2-5%. If it drops alot try raising it to where you want it and plug the IAC back in. Its commanded an idle rpm so it will close the IAC and not run any faster. Since you don't have the software that may not work as the tps will need reset.

I didn't blame it on the transmission (although it could be partially locking up or something). The megasquirt is using GM sensors, throttle bodies IAC...

nothing wrong with 'open source' EFI and EFI that uses GM sensors, it's just how the world works.

I second that you need to log it to catch it die. You'll see something happening whether it's a legit problem or a sensor acting up.

I'm not disagreeing with you at all.............but what I am trying to say is, new Challenger 5.7's are 25mpg. You are almost 1000 pounds lighter, you should be getting 28mpg out of that car.

Run the Chrysler drivetrain. That aftermarket computer is holding the car back.

My best guess is that either the transmission temp sensor or engine temp sensor is providing the correct reading on a dash gauge, but the milivolt reading to the computer is out of range (aka-shutting the car down to protect from over-heat damage). Milivolt readings are a definite issue with aftermarket sensors because they are built to a looser QA/QC than Factory sensors. I had first-hand experience with this on a throttle position sensors on a fairly old Chrysler OB2 system. The newer stuff ('06 and up) are even WORSE.

You can't beat Factory engineering on the Chrysler stuff. I know Ford and Blunder Motors systems you can get away with anything, but Chrysler stuff you can't. I had a Fellow parked beside me at a car show last weekend with a new aftermarket supercharged Mustang putting out 745hp. No check engine light. No issues. FULL FACTORY WARRANTY. Good faqqin' luck getting that out of a Gen 3 hemi on a dealers lot.

That's for the help. I reset TPC and raised the idle to 850RPM. Worked OK first time it was hot, we'll see. Was also thinking of putting the Air Temp sensor a different place outside the intake tube to see if intake air temp could be an issue. Hard to find anyone around hear familiar with EFI Source system.

Megasquirt uses whatever sensors you want it to use. You can configure it to run any sensor you have the specs on, at least for the version I am using on my dual TBI Plymouth flathead build.

Something other than a 797hp redeye on the lot?

I think you missed the Hot Rod aftermarket point I was trying to make.

I don't have time for this so I'm going to leave it to you.

The Guy had an RTR Mustang. Add up what that thing cost and what a Redeye costs and let us all know.

$21,000.00 for upcharge on the Mustang, you do the rest...................

Silly me, I didn't pay attention to the 'pay no attention' comment from another wise member. I won't make that mistake a second time.