70barracuda Posted April 16 Share Posted April 16 Having issues with an 86 2.5 TBI. The thing will start perfect when cold but once I drive it and it gets hot, its a total pain to start. Have to crank and crank and feather the gas pedal to get it to start. Once it starts its perfectly fine. I have replaced, CPS - no change Ignition box, coil, cap and rotor - no change CTS - no change AIT - no change Fuel pump - no change Rebuilt the tbi unit with new regulator and injector Cleaned up all engine grounds and added new ones - no change. Its driving me nuts. The truck runs awesome and starts great when cold. Its just the hot starts that are a pain. Link to comment Share on other sites More sharing options...
Eagle_SX4 Posted April 16 Share Posted April 16 My experience has been that is usually a vapor lock issue. Maybe try insulating the fuel line. DEI has some stuff that is great. I was able to get some at my local auto parts store. https://www.designengineering.com/heat-sheath-aluminized-sleeving-0-5-x-36/ Link to comment Share on other sites More sharing options...
70barracuda Posted April 16 Author Share Posted April 16 15 minutes ago, Eagle_SX4 said: My experience has been that is usually a vapor lock issue. Maybe try insulating the fuel line. DEI has some stuff that is great. I was able to get some at my local auto parts store. https://www.designengineering.com/heat-sheath-aluminized-sleeving-0-5-x-36/ Thats what I also have been thinking. I have stuff to make brand new fuel lines and ill be wrapping it in that. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 16 Share Posted April 16 Huh. Interesting. Can’t say I’ve run into that issue where at least the CPS doesn’t solve such an issue. I’m wondering if the ISA isn’t operating properly. Link to comment Share on other sites More sharing options...
watchamakalit Posted April 16 Share Posted April 16 Have we learned nothing from recent events? Sorry for the outburst there, have your checked ignition timing? Link to comment Share on other sites More sharing options...
70barracuda Posted April 17 Author Share Posted April 17 When I turn it off the isa moves the throttle back to open so I believe its functioning. It'll only start if I feather the gas and itll slowly come to life. If I don't do anything itll just crank and crank. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 17 Share Posted April 17 Huh. How interesting. Ok it’s resetting. Do we know if it has been adjusted at some point in its life? I’m almost wonder if it’s working but it’s not “working” like yeah it moves and makes sound but is it opening to the correct position for next start up kind of working. Just a thought. Does it have a full cluster? Link to comment Share on other sites More sharing options...
70barracuda Posted April 17 Author Share Posted April 17 48 minutes ago, eaglescout526 said: Huh. How interesting. Ok it’s resetting. Do we know if it has been adjusted at some point in its life? I’m almost wonder if it’s working but it’s not “working” like yeah it moves and makes sound but is it opening to the correct position for next start up kind of working. Just a thought. Does it have a full cluster? That part i do not know. Is there a writeup for it? Yes full cluster Link to comment Share on other sites More sharing options...
70barracuda Posted April 17 Author Share Posted April 17 Found your write up on it. Ill definitely be doing this tomorrow. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 17 Share Posted April 17 Sweet glad ya found it! As far as the full cluster, one little thing I’ve noticed with the tach is it bounces when cranking. That’s how I’ve been able to determine if it’s something in ignition. If that bounces, you should be good in terms of the ignition system. Like I’ve had a couple CPS issues and when the tach doesnt move, I unplug and plug it back in and it’ll fire right up. Link to comment Share on other sites More sharing options...
70barracuda Posted April 17 Author Share Posted April 17 12 minutes ago, eaglescout526 said: Sweet glad ya found it! As far as the full cluster, one little thing I’ve noticed with the tach is it bounces when cranking. That’s how I’ve been able to determine if it’s something in ignition. If that bounces, you should be good in terms of the ignition system. Like I’ve had a couple CPS issues and when the tach doesnt move, I unplug and plug it back in and it’ll fire right up. Huh interesting but good to know. Ill add it to the list of stuff to check tomorrow. I also just got the REM hooked up today and was playing around with it so I'm sure that'll give me some good info once I figure out the menus Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 17 Share Posted April 17 REM should provide some insight as well. Link to comment Share on other sites More sharing options...
70barracuda Posted April 17 Author Share Posted April 17 ISA was dead on doing eagle's procedure Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 17 Share Posted April 17 Holy crap! That’s a first. Usually that’s messed with by other when they have an idle issue. Link to comment Share on other sites More sharing options...
hgeranium Posted April 18 Share Posted April 18 What the heck is an ISA? Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 18 Share Posted April 18 2 minutes ago, hgeranium said: What the heck is an ISA? Idle Speed Actuator. It’s similar to the IAC but it’s only found on TBIs. You can find it on the GM cars and trucks and our own 2.5L. Link to comment Share on other sites More sharing options...
hgeranium Posted April 18 Share Posted April 18 25 minutes ago, eaglescout526 said: Idle Speed Actuator. It’s similar to the IAC but it’s only found on TBIs. You can find it on the GM cars and trucks and our own 2.5L. Good looks! I'll add that to my infinitely increasing internal inventory of acronyms Link to comment Share on other sites More sharing options...
70barracuda Posted 21 hours ago Author Share Posted 21 hours ago Is 18 psi a little high for the tbi unit? Link to comment Share on other sites More sharing options...
eaglescout526 Posted 20 hours ago Share Posted 20 hours ago A little bit. Pretty sure output should be 15psi Link to comment Share on other sites More sharing options...
70barracuda Posted 19 hours ago Author Share Posted 19 hours ago 8 minutes ago, eaglescout526 said: A little bit. Pretty sure output should be 15psi Hmmm I wonder if I'm flooding at all when trying to restart. Link to comment Share on other sites More sharing options...
eaglescout526 Posted 19 hours ago Share Posted 19 hours ago It lines up with having to feather the throttle to get it to restart. Maybe a regulator rebuild is needed along with new injector O-rings Link to comment Share on other sites More sharing options...
70barracuda Posted 17 hours ago Author Share Posted 17 hours ago 1 hour ago, eaglescout526 said: It lines up with having to feather the throttle to get it to restart. Maybe a regulator rebuild is needed along with new injector O-rings All brand new. Regulator was leaking when I picked it up so I rebuilt the tbi unit top to bottom. Injector is a brand new standard brand but I did also just order a brand new ac delco because I wasn't happy with the spray pattern on the standard injector Link to comment Share on other sites More sharing options...
eaglescout526 Posted 16 hours ago Share Posted 16 hours ago Huh. How odd. Was the adjustment screw exposed on the bottom of the regulator? Link to comment Share on other sites More sharing options...
70barracuda Posted 11 hours ago Author Share Posted 11 hours ago No screw wasnt exposed. Had to dig the lead out. Adjusted it down to 15 psi on the dot and replaced the fuel injector. Still does it. Definitely not as bad as before but still have to Crack the throttle to get it to go. No Crack, and itll just crank and crank and crank. But the moment I Crack the throttle halfway or so, itll fire no problem. Link to comment Share on other sites More sharing options...
eaglescout526 Posted 8 hours ago Share Posted 8 hours ago Well that’s definitely progress actually. Small steps to solving this one. We’re the injector o-rings replaced? Link to comment Share on other sites More sharing options...
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