Zoldman Posted December 16, 2003 Share Posted December 16, 2003 Ok, Not sure if this post belongs here; might also go to Drivetrain forum, but I'll try here first. I bought FJ201's yellow 260 with a 305 TPI speed density motor and non computer controlled 4L60 auto trans. The car is MAP/Speed Density with an ECM form a '90 vehicle (#1227730). Engine and trans are froma n earlier vintage, but all conversion stuff is present and after a few replacments and tweaking, is working fine. Car runs fine, just replaced injectors and a few sensors. It has one annoying habit that I can't shake, though. When coming to a stop, the engine speed dips suddenly, and then either the motor will totally stall, or the RPM jumps back up. It acts like the trans is loading the motor too much, but the line pressure is fine, and the lockup is not on. I read somewhere that the vehicle speed sensor controls some function of the idle air motor that opens it slightly when decelerating to prevent stalling coming to a stop. Something about the IAC not being able to respond quickly enough to compensate without help. Well, I don't have a VSS on this trans, and don't want to experiment blindly and have one installed without coming to the fount of knowledge for advice. I have searched the archives and find very little that applies, but I may be missing good info by not knowing what keywords/jargon to lead with. PLease help; this is a good car with mucho potential; it just is a real pain when it stalls so much. Currently, the only way to solve the problem is to set the idle to almost 900 rpm, and that is no fun either. Thanks Bill Boyd Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted December 16, 2003 Share Posted December 16, 2003 it may be the idle air control, My was doin' the same thing for months. pull up to stop and shut off. sometimes catch itself and sometimes not. but it would restart instantly. thought fuel press or something. I finally took the time to adjust the IAC per the conversion book i bought. Very involved process. I dismissed it as my problem for months as i was too lazy to take 20 min to fix it. the energy expelled cussing was 10 times greater than the fix. I think my book is out in my car (i'm at work) if i find time i'll get it tonight and copy it word for word and see if that helps. BTW: mine's an '86 TPI'd 305 (Mass Air sys but otherwise similar Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted December 16, 2003 Share Posted December 16, 2003 Also, mine does not have VSS either. After adjusting the IAC, my car drives like a dream. Good Luck with it, hope that's the prob. Quote Link to comment Share on other sites More sharing options...
Zoldman Posted December 16, 2003 Author Share Posted December 16, 2003 Charles, Thanks for reply. I tried to email you, but my mail got bounced back; says your box may be full. If you can find the instructions, I would really appreciate it. I thought I had the IAC adjusted correctly, but maybe not. Sure would be nice to fix it with time instead of money!! By the way, what the heck have you done to yor motor that you're getting the 1/4 mile time and MPH? Awesome. Thanks Bill Quote Link to comment Share on other sites More sharing options...
Zoldman Posted December 16, 2003 Author Share Posted December 16, 2003 Charles, Forgot to ask; what RPM are you running at idle? What trans? How did you set the base idle (before IAC is hooked up)? If you can't copy instructions, let me know what book you used and I will go get it. Thanks Bill Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted December 16, 2003 Share Posted December 16, 2003 Does your set up have a servo motor that regulates the throttle at idle? If so check it. Quote Link to comment Share on other sites More sharing options...
Zoldman Posted December 16, 2003 Author Share Posted December 16, 2003 Bill, No servo motor; base idle set by adjusting throttle plates. The IAC motor opens/closes in steps to adjust the amount of air getting past the throttle plates, so it serves the same function as servo motor does on other engines (I think). Bill Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted December 16, 2003 Share Posted December 16, 2003 Hey Bill, thanks for the compliments. doin' the bodywork now so maybe she'll look as good as she runs come March (next SEZS event). sorry for the e-mail probs. no computer at home till after new years and they locked us out of yahoo/hotmail mail at work. need to clear it soon. runnin 700r4 and idles at ~650. as for mods i got a 13.1 on stock motor/ heads with just a cam swap (2-5k Crane) and ram horn manifolds. Put on alum L-98 heads, roller 1.6 rockers and block huggers and only dropped 3 tenths will go 355 or stroker 383 next year. here are the steps in the book. i tried to set base idle before hooking up the iac without following the steps and that is where i messed up. she'd even shut off @ 60mph if i went to neutral and let off the gas. anyway 1.pierce the idle stop screww cup plug with an awl, and apply leverage to remove it. 2. With the IAC elect plug still connected, ground diagnostic Terminal "B" of the ALDL connector by jumpering it to Terminal "A". 3. Turn ignition to "ON" position. Do not start engine! Wait at least 30 seconds. 4. With ignition still "ON" disconnect the IAC elect connector. 5.Disconnect the distributor set-timing connector. 6.Start engine and allow to go "Closed Loop". (With the ALDL diagnostic terminal grounded the "Check Engine" light will blink 2.5 times per secind while in "Open Loop" and slow to once per second when the system changes over to "Closed Loop".) 7.Remove the ground from the ALDL diagnostic terminal. 8.Adjust idle stop screw with a 1/4" drive #T20 TORX socket to obtain 450-500 rpm in Park or Neutral. 9. Turn ignition "OFF" and reconnect elect connector at IAC motor. 10. Remove Fuse #1 (ECU power) for 30 seconds to remove Code 42 from memory. Hope this helps. i rigged a rocker switch to ground terminal A and B and hooked up a little park bulb at my ECU to be my check engine light. Quote Link to comment Share on other sites More sharing options...
Zoldman Posted December 16, 2003 Author Share Posted December 16, 2003 Charles, OK, that's not how I did it........must have screwed it up. I'll re adjust the right way this weekend when I get back. One thing I need help with....what is the distributor set timing connector, and what does it look like? I'm guessing it is near the Dist, but a discription would help. If you didn't disconnect it when adjusting, would it just tell the ECM to ignore what you had done? I'm still learning this computer car stuff............... By the way, you put a 383 in that thing, I hope you get a cage (and maybe a parachute?!) Good luck. Thanks Bill Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted December 17, 2003 Share Posted December 17, 2003 Bill, the connector is a one wire connector about 18" from the distributor towards the ecu (one of the 4 wires from the dist 4 pin connector, i believe). it is tan w/ black stripe. i left all but the connector in the loom on my firewall for easy access. it comes from slot D-5 on the larger connector to the ecu (A-B rows on small conn, and C-D rows on larger one). D-1 thru D-9 are as follows blk/wht, blk, blk/wht, wht, tan/blk, tan, purple, empty, empty. (Mass Air, Map setup should be similar) well, one thing about a 383. not a hp monster, but enough torque to run 11's with the right setup and 12's with a 20ft boat behind it. and then there's the 3 sec redlight to redlight runs. Quote Link to comment Share on other sites More sharing options...
Zoldman Posted December 17, 2003 Author Share Posted December 17, 2003 Charles, Thanks, I've got a MAP setup, but the wiring to the dist is similar, so I'll find it. You're right about the 383 being a torque monster. I've got a '79 Vette and stroked the motor to 383, went with mid level cam, Air Flow Research 180 cc heads, and an Edlebrock 795cfm Quadrajet. The damn thing will beat anything in town from light to light, and that's in a car that weighs 3400 lbs. It would be OK in the 1/4, but the 700R4 isn't the best for that distance. IF I was going to strictly drag the car, I think I'd go TH350 or 400. I like to cruise with it too, so the 700 is a the perect trans. Thanks again for all the help; good luck with your future motor! Bill Quote Link to comment Share on other sites More sharing options...
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