If you have not already, check the ECT sensor, a bad sensor could result in easy first starts but hard starting when warm, A/F ratio could be very rich on warm starts making starting difficult . 94
^^good call. definitely suspect. however, you would think it would run like crap all the time when warm. not just first 5 minutes
well seeing as I do not own an oscilliscope that test is out for me… would need a mechanic for that one at which point it is cheaper to just replace the thing lol. I’ll check the ect as well, but haven’t suspected it as my cooling fans kick on just fine at warm idle. is there a resistance or continuity test I can do with my Fluke multitester to determine a bad ECT? Actually thinking about it yesterday I was having overheats at idle while being stuck in heavy mountain traffic… so I am def gonna check the ECT.
and it only runs like crap for about 30 seconds after a hard warm start. soon as the mis fire resolves it idles just fine… the biggest pain is getting it to start and the issue is intermittent. as of the last couple days it catches and with a little feathering starts right up… I definitely suspect a sensor is involved… Main relay clicks 2 sec after CEL shuts off.
And I have checked my blinking code light under the passenger floorpan and it is showing nothing.
Oh yes the car is a 1991 GS.
Thanks for all the help guys. I do appreciate it!
the ect sensor is separate from the fan and gauge circuits.
the fan is turned on through the thermo fan switch
the gauge is read through the sender.
the ect sensor relays coolant temp to the ecm. it’s an ntc (negative temperature coefficient) sensor. this means that as temperature rises, it’s resistance lowers. opposite of conventional electrical theory. so on a warm engine, you should be reading i dunno, somewhere around 100 ohms. the exact number isn’t important. when they go, you know it. the readings are way out to lunch. like you’ll read 10,000ohms warm or something.
i don’t think it’s the problem, as it would be occuring all the time warm. but who knows, maybe the ecm sees the o2 readings and lowers the injector duty cycle and that’s why you get it for the first 30 seconds. kinda doubt it, as it’s only a 91. not very sophisticated stuff.
what EXACTLY did your mechanic say about the cam sensor? car would run with a bad cam sensor too. poorly albeit, but that would throw a code for sure.
also, how is your fuel mileage?
i’m still thinking it’s a sticking iac or fitv. on older vehicles like this, sensors throw codes. actuators do not. and the iac is an actuator. i dunno. it’s a common issue. always best to start with the common stuff
Mechanic was relating the CPS to the issue under the assumption that when the car is warmed up the heat stresses the sensor throwing readings out of whack, thus causing the engine to try to fire on the wrong cylinder, and continuing in such a manner until the engine catches on a cylinder, then 2 then all of em.
he explained it way better than I just did, but made sense and his description of the issue and symptoms pretty much sounded like it may be spot on.
I am ruling nothing out tho. I have also had a couple local teg fanatics mention IACV so I am gonna clean that out while I re-do all the vacuum lines that are looking worn or excessively dirty in conjunction with also installing my CAI. (not to say anything is really all that dirty seeing as this is the cleanest honda motor I have seen) regardless of cleanliness… Pretty sure I’ll be alot closer to narrowing this down after I get a chance to put the parts I got this week on. the issue is more of an annoyance than a hinderance…
[QUOTE=djzachtyler;2266689]Mechanic was relating the CPS to the issue under the assumption that when the car is warmed up the heat stresses the sensor throwing readings out of whack, thus causing the engine to try to fire on the wrong cylinder, and continuing in such a manner until the engine catches on a cylinder, then 2 then all of em.
[/QUOTE]
what you’ve just explained here is actually pretty much the exact interaction between cam sensor and ecm. the ecm relates cylinder position on what’s called adaptive learning. every time you fire the car up, the ecm must learn cylinder position. it has no idea where it is until things start moving. upon start up, the ecm actually fires all 4 injectors and waits to see which cylinder fires. big fuel party. this is how the ecm learns cylinder position. and that happens every time you fire it up. if the cam sensor is inoperative, usually the ecm will just continue firing all injectors at every tdc event, and set a DTC.
usually a cam sensor will just not operate proper and that’s it. the pick up coil will short or open or the conductor will become damaged/weak. won’t USUALLY be intermittent. anythings possible though, i guess. heat definitely could effect a failing cps. like i said though, personally, i’d be looking at the more common susceptibilities first instead of shooting into left field. also, would think there should be a code thrown though if it were a cam sensor issue. however, being it’s a 91, the obd capability is pretty limited.
if you do go ahead and clean the iac, do it on vehicle. KOER, shoot the carb cleaner into the iac port at the throttle body. snap the throttle a few times while doing this. this will exercise the iac and give it a thorough rinsing. repeat that a few times. by doing it on vehicle, you ensure that the port gets cleaned as well
that is awesome info man thanks a bundle. I surer hop this thread is able to help others that have dealt with this issue. I have seen many regarding this but never a complete solution. And that was the exact explanation my buddy gave me.
Should have time tomorrow or Wednesday to get what we have discussed so far taken care of. so will update the thread at that point.
ok so after work today I got the new distributor installed, put in the replacement map sensor, and while I was at it installed my AEM intake & cleaned out the IACV (probably shoulda skipped the intake, but figured what the heck…) waiting to see if I still have the starting issues, but now have very weak power starting out in first and lower RPM. Once I hit about 2500 RPM it kicks in… I had to rotate the new distributor all the way left to keep the engine running so I am guessing my timing is off a tad. I have a timing light but need to know how to check timing on this car and make adjustments, or if I should just defer this part to the mechanic friday when I take him the car.
I also did make sure the rotor in the new distributor was in the same position as the old rotor before removing it and installing the new one.
and my main issue is still present. damn thing is still starting up rough at a warm start. I was better off before changing all these parts haha. Oh well ima reset the ECU and see if it helps any but definitely still go a ways to go. I fear I have a failing head gasket tho as I have been losing coolant and have pretty much replaced the entire cooling system 
No coolant in the oil or vice versa & last compression check would indicate otherwise, but I do suspect it all the same.
Upside is my engine compartment sure looks nice!
http://i755.photobucket.com/albums/xx199/djzachtyler/IntegraEngine.jpg
man I just went out and it starts but definitely seems like the timing is off… after I feather the gas the idle evens out, but still lacks lower RPM power. I may just put the old distributor back on until I can get my mechanic to look at it.
did you run an idle relearn? let it idle for 5-10 minutes. the ecm needs to relearn iac position.
to check timing, jump the service connector to get into base timing mode. this prevents the ecm from making counter adjustment while you adjust manually. this MUST be done in order to adjust timing. since you’ve tried adjusting timing without doing this prior, your timing is going to be way off. you need to get into base timing mode. with the vehicle warmed up, install the probe to the #1 spark plug wire. there are 4 marks on the crank pulley. 1 on its own, which is #1 tdc. and 3 otheres, 14,16 and 18*btdc. point the light straight down at the timing notch in the cover, lining it up with the marks on the pulley. you want the light to flash at one of the 3 marks. by turning the distributor towards the firewall, you will be advancing timing. retard towards radiator. just google it. you’ll find a zillion videos
where is the service connector located? - I’ll answer this myself for anyone else reading this… it is located under the passenger floor-pan behind the center console to the left of where the kick-plate covering the ecu is. google is god sometimes…
distributor is already turned all the way towards the firewall… was also the case with the last distributor, so any adjustments made there are pretty much not going to happen. if I rotate the distributor towards the radiator the cars idles super rough and then dies completely.
Check mechanical timing and make sure everything is TDC.
Distributor should never have to be turned all way towards any direction.
That is the plan.
Car definitely feels like mechanical timing is off… if I were to wager a guess with the distributor all the way to the firewall the timing is still retarded by about 2-4 degrees.
Timing light will tell all when I get home from work today. I’ll update the thread then.
Well the position of the distributor is already telling all.
Pull off the valve cover and cam gear covers and check to see if they are at TDC first. Then proceed with ignition timing.
Overheating in traffic huh? Hard start misfires ehh? Time for a compression test my man… Check coolant level and look for any excessive pressure in the radiator. You dont have to be blowing white smoke to have a blown HG.
ended up putting the old distributor back in and during the swap noticed that the new one despite being marked as a TD23U had the rotor was about 30 minutes off from an OEM TD23U so where as the old distributor would have the rotor sitting at 9:00 the new one would have the rotor sitting at about 8:30. Anyways at least I can still get my money back on it to reinvest in other areas.
Put the old distributor back in and timing was fine without advancing it at the distributor. Can feel the difference in acceleration with the AEM Intake now.
Compression test about 2 weeks ago ( when issues started ) read Cyl 1 = 175 Cyl 2 = 175 Cyl 3 = 170 Cyl 4 = 175 I’ll check again this weekend. If any cylinder was suspect though it would be #4 as the spark plug was crusty and white, but on the outer surfaces that sit in the valve cover area just below the porcelain. Coolant level seems to drop off a little every few days, and I did notice some pressure in the radiator when opening the radiator cap while the engine was cool.
internally all plugs look normal. no odd crust, just the common reddish brown burn off on a normally operating plug. Plugs were the first thing I checked.
On a side note I saw a guy on CL selling a full B18A1 motor with everything it needed (block, head, valve cover & oil pan ) for 215 bucks locally… thinking about snatching it up and starting a project build for when this motor gives it up.
I think I have become a DA junkie… (facepalm)
Sounds like a decent deal. Pull the radiator cap and let the car idle for a while. Watch for air bubbles, if they never stop suspect HG. The first time that happened to me I found a small crack right under the coolant bleeder valve so check that as well. My B17 is doing the same thing but much worse at this point. Starts fine sometimes, barely at other times. No smoke but so much air in the coolant system and a hint of oil. HG/valve seal replacement this weekend…good times
Oh I bet… I am looking at doing the same myself this next weekend. Found my torque wrenches I thought we stolen, so probably undertake this adventure myself.
I’ll be doing my 3k oil change as well so will have to look for coolant in the oil when I drain it.
This issue is soo goofy it isn’t funny.
FYI I have spen hours looking at the radiator with the cap off to try to determmine if I was getting exhaust into the cooling system. Only odd thing is that you would think that the issue would be worse when the car is cold as the gaskets will shrink up, and less pronounced when it is hot as they are expanded.
I need to order a ECT sensor and try swapping that out as well. another low cost part that I can at least rule out.
just to update…
issue seems to have disappeared except intermittently? for a week now no tsarting issues, except once after a short highway jaunt to a client office. Parked for 20 minutes, went out tried to start her up and “BANG” huge backfire then wouldn’t start for 5 minutes…
then right as I was getting fed up and thinking I’d need 24 hour roadside… car turned right over and started up. in fact since then the only issue I had was a small hose at the back of the engine block blew yesterday and shot coolant all over the engine compartmentr… replaced the hose and aside from the residual smell of coolant burning off things seem ok…
Aaaand :rimshot: so the issue was the o2 sensor was bad… put in a new denso o2 and have not had starting issues.
Sensor was bad because I do indeed have a small headgasket leak… not enough to leave antifreeze floationg in the oil, but enough to leave an almost unnoticeable slightly milky deposit from evaporation in the very top of my oil cap as well as intermittently leave almost unnoticeable amounts of white smoke at the exhaust.
02 sensor I pulled out had white crust on one side and typical red brown deposits on the other… That said I know what my next project is going to be. get ready for a head gasket change or get another engine and do what others have done and get ready for a swap project!!! :ohyeah:
Seems engines go for less than a rebuild anyways. That and I have seen a few nicew swap project motors locally that were built up and never dropped in the car they were intended for. Either way I at least found my answer.
Got a line on a 98 Ford Escort ZX2 thrugh a buddy for $250 needs brakes/rotors and possibly a fuel pump &/or filter and it is good to go… figure I can use that as a DD while I prepare to really get down and dirty with the teg 