Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: cougrrr302 on June 15, 2011, 09:03:45 AM

Title: Tuning CFI
Post by: cougrrr302 on June 15, 2011, 09:03:45 AM
After 14 years of sitting, and a few years of driving off and on my Cougar still seems to have a dead spot in it. I've turned down the fuel pressure which helped, I've replaced the o2, I put a new distributor/plugs/wires on it a few years back. I need to find a suitable replacement for the ignition.

When I am accelerating it hesitates if I give it more the 2/3 throttle. Full throttle it bogs and coughs and will have little spurts of acceleration. I just drove it and was revving it up, and even at higher rpm it seems to choke, or just have nothing. Any ideas? I'm not good with engine work, I know body work.

I'm looking to convert it to carb, but I would really like to make sure the ignition is ok first.
Title: Tuning CFI
Post by: ipsd on June 15, 2011, 09:15:47 PM
Have you tested the Tps? Sounds like it might have a dead spot in it.

Hope this helps
Stuckman
Title: Tuning CFI
Post by: ipsd on June 15, 2011, 09:19:06 PM
Have you tested the Tps? Sounds like it might have a dead spot in it.

Hope this helps
Stuckman
Title: Tuning CFI
Post by: cougrrr302 on June 16, 2011, 02:22:29 AM
I'm not familiar with engines enough to know how to check the TPS, I know what it is(Throttle Position Sensor) that's about it. I need to pull the injectors and test them to see if they are working good. They're 27 years old. Plus I need to shop around for a nice distributor, ignition coil, plugs and wires.
Title: Tuning CFI
Post by: mcb82gt on June 16, 2011, 08:09:56 AM
Those symptoms make me think possibly fuel.  Wonder about the fuel pump.  Is the fuel filter new?
Title: Tuning CFI
Post by: Carl on June 16, 2011, 10:35:13 AM
I was having the same problems with my 84 Cougar right before I did a 4 barrel carb conversion.  I could never quite figure out the CFI, and that's why I ditched it.  If you have a couple hundred dollars and a weekend you definately should convert to a carb.

Use the duraspark II ignition.  It was like $30 or something from an autoparts store.  Looks like a little silver box.

I was not good with engines at all when I did the conversion and it turned out great! :)

Good Luck!
Title: Tuning CFI
Post by: ipsd on June 16, 2011, 11:30:19 AM
To test the TPS you probe the wires believe the green and the black wires. The pigtail still has to be plugged in so back prob or use some pins to make contact with the wires.  With the car on but motor not running. With the accelerator untouched you should see that it is pretty close to 1volt. Then as you work the throttle. The voltage should increase as you open the throttle more. As you slowly work the throttle watch the meter for any drop outs of voltage. It is easiest with and old school buttstuffog meter with the needle style gauge.

Hope this helps
Stuckman
Title: Tuning CFI
Post by: cougrrr302 on June 17, 2011, 01:28:00 AM
If I had the time to check the voltage I would. I think I'm gonna carb it and try to find alittle healthier cam and maybe do some minor head work just to get some pep out of it.

Carl, if you could send me a list of the parts you had to buy(if you remember all of them) I would greatly appreciate it. I really want to get this things hopping on its toes. I love driving it more than any car I've owned, and even though it runs fine and averages 23 mpg, I still don't feel 100% confident when it has problems when I lay into the throttle.
Title: Tuning CFI
Post by: cougrrr302 on June 17, 2011, 01:31:22 AM
You can kinda hear the hesitation in the video I posted on youtube of the exhaust I just put on.
[video=youtube;MDshHiFwZHc]http://www.youtube.com/watch?v=MDshHiFwZHc[/video]
Title: Tuning CFI
Post by: Carl on June 17, 2011, 02:39:58 AM
Quote from: cougrrr302;361609
If I had the time to check the voltage I would. I think I'm gonna carb it and try to find alittle healthier cam and maybe do some minor head work just to get some pep out of it.

Carl, if you could send me a list of the parts you had to buy(if you remember all of them) I would greatly appreciate it. I really want to get this things hopping on its toes. I love driving it more than any car I've owned, and even though it runs fine and averages 23 mpg, I still don't feel 100% confident when it has problems when I lay into the throttle.

 
Oh btw I meant to say duraspark II distributor... not ignition. Dunno what I was thinking.

Ok I will think up everything I did and let ya know!
Title: Tuning CFI
Post by: cougrrr302 on June 17, 2011, 10:47:47 AM
I appreciate it! I just want this thing to drive like a dream. I drove it around this morning, and it's still got alot of hesitation going on.
Title: Tuning CFI
Post by: Carl on June 21, 2011, 11:34:08 AM
Ok here is everything you should need.  I would recommend you get a new fuel pump sometime in the future too.

The intake manifold and carb don't really matter as long as they work with a 302.  Make sure your ignition system / distributor is Duraspark II

http://www.summitracing.com/parts/EDL-2121/

http://www.summitracing.com/parts/HLY-0-80457S/

http://www.summitracing.com/parts/LOK-KD2AODHT/Application/?prefilter=0

This article will help when hooking the distributor up to the ignition module

http://sbftech.com/index.php?PHPSESSID=81ad00a0c86167bb1de043cb27abceff&/topic,1754.0.html

My thread from when I did it

http://www.foxtbirdcougarforums.com/showthread.php?13953-TBI-to-Carb-Progress-Pics.-(Almost-Done!)&highlight=

Another thread when I was having probs hooking up the dizzy

http://www.foxtbirdcougarforums.com/showthread.php?14031-Spark-Problems&highlight=

This should be it man, if you have any questions let me know!
Title: Tuning CFI
Post by: A-drian on October 22, 2014, 07:48:28 PM
Cool car... I'm new to this forum I was googling when I saw your problem. I know it's not a t-bird but it is a 302 with cfi and I had that same problem. After looking around I saw this article written but some guy. He suggest putting a 2bbl carb spacer under the cfi but a 2bbl spacer with one single hole. I did this on my car and it doenst choke at wot anymore.  http://www.grandmarq.net/vb/showthread.php?22245-New-CFI-Goodness