Intermittent Check Engine - No Codes February 24, 2008, 01:40:41 PM 84 Cougar, 3.8LCheck engine comes on intermittently while in drive at stop or decelerating below 5MPH. Light goes off if transmission changed to Neutral or Park.Battery checks good and alternator putting out 14.16 volts.Both on Demand and Continuous pass.Any suggestions??? Quote Selected
Intermittent Check Engine - No Codes Reply #1 – February 24, 2008, 02:14:07 PM If you think the cfi has no carbon build up and is clear on the rear driver fitting,Then try turning up the idle a wee bit. First off though, check your fuel presure while driving cause if the fuel pump is dropping in psi a wee bit, this could cause a slight stumble in the begining stages of a fuel pump going out. Quote Selected
Intermittent Check Engine - No Codes Reply #2 – February 24, 2008, 05:59:50 PM Thanks for inputQuoteIf you think the cfi has no carbon build up and is clear on the rear driver fitting, Then try turning up the idle a wee bit.Just had engine rebuilt, so hopefully no buildup. Current Idle seems a bit high, but GOOD SUGGESTION.QuoteFirst off though, check your fuel presure while driving cause if the fuel pump is dropping in psi a wee bit, this could cause a slight stumble in the begining stages of a fuel pump going out.Fuel pump less than 2000 miles so should be OK. Quote Selected
Intermittent Check Engine - No Codes Reply #3 – February 24, 2008, 08:15:34 PM check the coil Quote Selected
Intermittent Check Engine - No Codes Reply #4 – February 24, 2008, 09:07:50 PM 84 doesn't have an amber check engine light. It has a red engine light.It comes on if the engine is too hot or the oil pressure is too low.In your case it sounds like the oil pressure is going too low at slow engine speeds. Quote Selected
Intermittent Check Engine - No Codes Reply #5 – February 24, 2008, 10:20:27 PM Thanks for responses.Softtouch will definitely check oil pressure. Quote Selected
Intermittent Check Engine - No Codes Reply #6 – February 25, 2008, 12:21:07 AM had the same problem with my old 83 5.0 motor.... the red light would blink at me when i was at a stop in gear..... i bumped up the idle to about 850 rpm and it went away.... Quote Selected
Intermittent Check Engine - No Codes Reply #7 – March 02, 2008, 08:37:55 AM The 3.8, Throttle Body idle is supposedly controlled by the EEC-IV.My guess is its a combination of throttle position sensor and distance of DC idle motor plunger which feeds the proper voltages.A small adjustment can be make (DC idle motor), but I've got the right gap (7/32 inch per TSB) , and DC idle motor adjustment plate is as far as it will go (knocking up against the hold down plate screw).Beside coil (can't see why this would have an effect), would the TFI heating up a little possibly change voltages. When Cold, idle fine, only after 15-20 miles driving does problem arise. Quote Selected
Intermittent Check Engine - No Codes Reply #9 – March 02, 2008, 10:18:14 PM Softtouch - same picture as my shop manual, except calls for 9/32 before the TSB change to 7/32.BTW, I have the 1984 shop manual (3 large books plus the Electrical and Vacuum manual) if you need anything you can't find. I also made an alpha master torque list by object (e.g. alternator bolts...) for quick reference if of interest.============================Checked ISC today, off slightly after tightening hold down screw, so reset so correct after hold down screw tightened, but still getting same issue.Any suggestions on how to check:1) Overheating (other than light)2) Monitoring oil pressure (other than light)ThanksDavid Quote Selected
Intermittent Check Engine - No Codes Reply #10 – March 03, 2008, 07:04:18 PM I also have the 84 shop manuals.You can isolate which sensor is turning on the light by pulling the wire off of them one at a time.I have an oil pressure gauge that I got from J C Whitney for $20.99 including shipping. Quote Selected
Intermittent Check Engine - No Codes Reply #11 – March 04, 2008, 08:22:48 PM Softtouch:Re-siliconed the TFI, inside of plug wire boots, and coated the top of the rotor blade. Will see if I still have issues tomorrow. Three questions re:QuoteYou can isolate which sensor is turning on the light by pulling the wire off of them one at a time.Since I'm not generating any codes, what will this accomplish other than to throw a code -- unless I'm missing something.Quote have an oil pressure gauge that I got from J C Whitney for $20.99 including shipping.I have never seen anything in the shop manual regarding where to hook up for testing oil pressure. Can you provide page reference or explanation please.QuoteRe: Rotors , Distributors CapsSee shop page 15-74. I use to use multipoint rotors, but haven't been able to find them for years. Per page 15-74, the blade type rotor requires alot of silicon grease. I find after running awhile the silicon seems to get on the inside cap poles and gets encrusted (hard deposits) which impacts running.Are you using silicon on your rotor?Do you have the same problem?Any estimate on the life (miles) your getting from your cap and rotor?ThanksDavid Quote Selected
Intermittent Check Engine - No Codes Reply #12 – March 05, 2008, 09:55:02 AM remove your oil presure switch and install your oil presure guage in the same hole.I commented that the CFI has carbon buildup. Ill bet the farm your good ole enigine rebuild had nothing to do with the CFI. That part got ignored when the rebuild was done im sure. No one cares to look there.Your symptoms sound more like oil presure related so perhaps someone took a short cut on the parts.DId the shop produce all the old part? What about the crank? What about the oil presure proportioning valve in the timing cover, what about the old oil pump gear set on the timing cover? What type of wear pattern was on the old bearings?Basically, if your oil presure is 20 or so psi and never gets anywhere near 40 plus, the shop f'ed you over. Im gonna guess the oil presure at idle is in the teens because of the calibration range of the manual oil presure switches and how they range from open to close contact.I wouldnt worry so much about the idle control motor because you can just set it anywhere to get the engine rpm stable at idle (if thats your goal). Worse case there would be a code thrown for the Idle Tracking Switch which can be taken care of later. All you need to do is figure out if setting the idle to 600-800rpm cures the problem with the light. Since you dont have a tac, it will all be by ear.Another idea would be to clean the ACT sensor of any sludge buildup. Also measure the resistance when its cold (bout 50kohm) and the same goes for the Coolant Temp Sensor , same resistance as well per my diy link as well as both our shop manuals. Quote Selected
Intermittent Check Engine - No Codes Reply #13 – March 05, 2008, 10:13:25 AM Quote from: softtouch;207520I also have the 84 shop manuals.You can isolate which sensor is turning on the light by pulling the wire off of them one at a time.I have an oil pressure gauge that I got from J C Whitney for $20.99 including shipping.and also you can pick up the oil guage sold at many car stores that is intended to be mounted in your dash. Just use that as an oil presure tester and make it your tool. Comes with all the correct fittings as well. Just leave the brass fitting that screws into the oil presure switch hole loose so you can install it by hand. Quote Selected
Intermittent Check Engine - No Codes Reply #14 – March 05, 2008, 05:16:56 PM Quote from: dw85745;207677Since I'm not generating any codes, what will this accomplish other than to throw a code -- unless I'm missing something.The sensors that turn on the "engine" light do not set codes and have nothing to do with the EEC. They are simply switches that when closed, provide a ground to turn on the light.When you turn the key on and before you start, the engine light is on because you have no oil pressure.QuoteSee shop page 15-74. I use to use multipoint rotors, but haven't been able to find them for years. Per page 15-74, the blade type rotor requires alot of silicon grease. I find after running awhile the silicon seems to get on the inside cap poles and gets encrusted (hard deposits) which impacts running.Yeah mine originally had the multipoint rotor. I don't put the silicon grease on mine. Probably should.I only drive it about 1000 miles a year. Been probable 15 years since I replaced the rotor. Quote Selected
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