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Topic: Stalling when warm after HO swap (Read 1309 times) previous topic - next topic

Stalling when warm after HO swap

So the machiene shop swapped the cam out to the correct one:D . The car runs good except for one annoying problem. When I start the car up it idles ok (~1,000 rpms) and I put it in reverse and it goes into gear fine and then will shift into drive fine. When the car is running it runs great. It ldles good at lights runs out good ect. Here's the problem. After the car is warmed up (driven about an hour) if you shift out of drive to go to reverse the car stalls and just dies. I can start it right back up it'll idle fine but the minute I put it in gear it stalls and dies. I end up having to throw it in gear and hit the gas almost instantaneously to keep the car running or it will stall. If I let it sit for about an hour it'll be fine. The engine has GT-40P heads, a Comp 266HR cam, and a stock HO intake. I've narrowed it down to three things I think could be wrong:
1. The cam is messing with the computer after the car is warm and I need to get a chip burnt for the car.
2. The IAC is screwed up.
3. My 20 year old original TFI is going out.
Any ideas guys?
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Stalling when warm after HO swap

Reply #1 –
Well I found something out. If I bump the idle up to 1050 rpms when it's warm it'll go into R or D ok. I have to bump the throttle a little after shifting so it doesn't stall but it will run. It idles at 900 rpms in gear though so it's a bit high but it doesn't stall. I might have to bump it up to 1100 rpms to get it to shft when warm ok though. The car has a Comp 266HR which specs are : durration @.50 210 intake/216 exhaust, lift with a 1.6 rocker .533 intake/.533 exhaust. It's supposed to work with SD and in drive the idle dosen't hunt or lope at all. It's just when it's warmed up and I change gears that it stalls:hick:
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Stalling when warm after HO swap

Reply #2 –
Do you have any codes? You shouldn't have to adjust the Idle speed to correct this problem.  The ECM should maintain an idle speed in the 550rpm range at idle in park.  When you place it in drive, the IAC should allow more aiflow to bump up the engine idle so that it doesn't die. Make sure the connector on the Trans has a good connection, so that the ECM knows you are in gear.
1988 Thunderbird
306 HO w/ A9P processor
AOD w/ Transgo Reprogrammer
Full Digital Dash w/ twin Cyberdyne A-pillar gauges 
245/50/16 Tires on Snowflakes
Engine swap - CA smog compliant

Stalling when warm after HO swap

Reply #3 –
That cam is at the outer fringes of driveability for a SD eec-IV setup.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Stalling when warm after HO swap

Reply #4 –
Uh I fixed it and it was the easiest thing ever :hick: . I swapped out the stock T-bird MAP sensor for a Mustang one. Car runs fine now. Either mine was  or there is a small difference between the two. I did notice that the body on the T-bird one was bigger than the Mustang one though.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Stalling when warm after HO swap

Reply #5 –
Hey, didn't you have a cobra intake on your other motor? Why not on this one?
~1988 thunderbird~
In hibernation, waiting for spring.

Stalling when warm after HO swap

Reply #6 –
Quote
I did notice that the body on the T-bird one was bigger than the Mustang one though


Hmm, that's interesting.  I've never noticed that.  Can you take some side by side pics of the two?
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Stalling when warm after HO swap

Reply #7 –
Quote from: thunderjet302;142482
Uh I fixed it and it was the easiest thing ever :hick: . I swapped out the stock T-bird MAP sensor for a Mustang one. Car runs fine now. Either mine was  or there is a small difference between the two. I did notice that the body on the T-bird one was bigger than the Mustang one though.


Possibly you had a Calif emissions MAP???? Maybe a difference... I've tried at least a half dozen different BAP &/or Maps on mine, never been able to detect a difference(course I'm Mass Air)... I believe I have a Turbo Coupe BAP on it at the moment...

I keep the idle set on mine with the Stage-1 Trick Flow cam at 1100 in neutral... Idles about 950 in gear... IF I idle it back, you can bet your ass it's gonna stall when hot...

I'm using a A9L 5 speed Mass Air EEC, but the car does the same thing on the A9P and C3W1 automatic EECs... (and always has)...

Stalling when warm after HO swap

Reply #8 –
Quote
I keep the idle set on mine with the Stage-1 Trick Flow cam at 1100 in neutral... Idles about 950 in gear... IF I idle it back, you can bet your ass it's gonna stall when hot...


Mine's the EXACT opposite.  Neutral idle 950.  In gear 800.  GREAT when warm.  CRANKY SOB on startup when the temperature drops to below 20 and she's been sittin overnight....
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!
 

Stalling when warm after HO swap

Reply #9 –
Quote from: TurboCoupe50;142597
Possibly you had a Calif emissions MAP???? Maybe a difference... I've tried at least a half dozen different BAP &/or Maps on mine, never been able to detect a difference(course I'm Mass Air)... I believe I have a Turbo Coupe BAP on it at the moment...

I keep the idle set on mine with the Stage-1 Trick Flow cam at 1100 in neutral... Idles about 950 in gear... IF I idle it back, you can bet your ass it's gonna stall when hot...

I'm using a A9L 5 speed Mass Air EEC, but the car does the same thing on the A9P and C3W1 automatic EECs... (and always has)...



It's possible that the California MAP was different. The car was bought new at Magic Ford in Santa Monica, California in Oct. 1987 by my cousin. When I get a chance I'll take a shot of them side by side to show the difference. Side to side the stock one was about 1/2" wider. 

I have mine set to idle @ 1050 rpms when hot in neutral and 800 rpms in gear and with the Mustang MAP it runs fine. I took it on a 25 mile drive yesterday and when I got back home it shifted between D and R fine. The Mustang MAP also cured the loping idle I had every once in awhile. If I was on the gas and suddenly let off and braked the car would surge while stopped with the brake on. Maybe the California MAP was different. After all they did have different emissions standards. I'm also running this on a 1989 Mark VII computer with no problems.

The Comp 266HR is a nice little cam though. It has very good low end torque and it'll pull really good up to about 5,500 rpms. As a plus it works with SD.

In a few months I'm going to see if this thing will run with a Cobra intake. I'll be the only one on the board with a SD HO car with non stock heads, cam, and intake:hick:
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Stalling when warm after HO swap

Reply #10 –
Quote
In a few months I'm going to see if this thing will run with a Cobra intake. I'll be the only one on the board with a SD HO car with non stock heads, cam, and intake


It'll run just fine with that intake.  I'm glad to see other people realize you can hop up a speed density car.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!