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91 XR7
08-10-2009, 05:39 PM
Yep tht's right, my '91 SC still has a Hot start issue, and it's now driving me nuts.. I know i bought this car for a challenge but DAMN!!

Replaced with NEW:
Sparkplug
Sparkplug wires
Fuel Filter
Cam Sensor
DIS module
ECT sensor
TPS (?? I think i did?)

On the car is a '93 PN (Read OE Ford) Crank sensor that looks to have been replaced recently (IE Loom is clean, Wires clean Sensor itself clean), Balancer is looking good with no cracks in the rubber, and spins straight..

Fuel Pressure is good, 40ish KOEO and 30ish KOER (Mechanically 100PSI guage) FP held good, after like 30-45 minutes it was still in the mid 20 PSI range, instanly came up when key was turn to run, and stayed good during cranking and starting..

When Cold the car starts great, sometimes with in a quick hit of the key.. once warm it can take like 5 or more seconds of turning it over to get it to start.. with the odd times it running at around 400rpm, and if left Black smoke will start coming out of the exhuast and it can run like that for some time.. with out throwing a code either!!!! But usually if you press the gas pedal a hair, and it gets up to like 500-600RPMS it'll catch fully and go up to like 1500rpms and settle back down to it's proper RPM like if nothing happened :eek:

Ground issue? Even thou i upgraded the factory grounds (4ga from battery to chassis and chassis to engine along with Battery to Alternator (Ground and Postive))
MAF sensor?? Down side i have no spares unless one from a '89 XR7 will work?
O2 Sensors?? (like it reads those for the first few seconds of running)
ECU itself??

Thanks

J dot Miller
08-10-2009, 08:59 PM
Do you have vacuum leaks? What is your vacuum? Check our your PCV valve. Clean it up and make sure it rattles.

Another possibility is the coil on the DIS.

frdlvr30
08-10-2009, 10:57 PM
MAF or IAT gets my vote. An educated guess, but just a guess.

91 XR7
08-10-2009, 10:59 PM
vacuum is around 20 inches of Mercury at idle, I've haven't double checked it with an Test gauge thou..

And I've recently went through everything to reseal everything, replaced a few hoses since i didn't like the looks of them (seemed to be okay, but questionable)

The PCV was good and clean too.. (checked it when i had the SC off doing the snout seal)

Also tried a different coil with out any change..

slowpoke
08-11-2009, 12:06 AM
and if left Black smoke will start coming out of the exhuast and it can run like that for some time..

im thinking with the black smoke there might be the possibility of a crack in the head/heads or a bad spot on the head/heads gasket. it almost seems like your problem is when it get warm threw expansion you might be getting some oil in the cylinders, KEEP IN MIND THIS IS JUST A THOUGHT! so dont panic. what did your recent plugs look like, is your oil staying at proper level, is your coolant clean or is it turning orange. if all those things are ok then you can most likely rule out head problems. i will say at times mine dips to low rpm when starting out at warm to hot temp, it goes away in seconds. from what ive gathered its my egr going out. that might be something to look at to.

91 XR7
08-11-2009, 12:59 AM
Coolant level and color is good..
There is oil loss, but it does have 110,000 miles on it.. in 3,000 miles i've added like 2 pints?
Spark plugs other then Worn looked good.. Not oiled or carboned up..

The car did fail emissions testing twice in it's life, and has `new' Cats in it (crudely installed) But when i had it tested it passed with flying colors, differently better then my '96 XR7 with a 4.6L :)

rad70
08-11-2009, 02:12 AM
black smoke is always too much fuel, white smoke can be coolant or oil, oil smoke will have blue tinge and stink, I'd be looking for fuel burn/mix problem.
90 SC owner

91 XR7
08-12-2009, 05:38 PM
I'm certain that is running rich when it does it's lumpy 400RPM idle, since it does have that typical rich smell..

I'll be checking over the wiring soon enough.. i may even try running a 14Ga ground to select areas of the ignition system for a better grounding.. I'm just suprised with all the issues these cars have had.. no one has had this one or knows a fix to it.. In the local club i hand out with.. there is another SC owner with the same hard to start when hot issue as mine...

MAM
08-13-2009, 02:00 AM
wow my car started doing the same thing about a week ago. starts up great when cold, but when the engine is hot, it actually doesnt start at all. i went to the store to grab something and when i got back in my car, it just cranked and cranked, i could hear the fuel pump running, and my upshift light was off.let is sit for about an hour and when it finally started idle was real low and car was running extremely rich, accelerator would not respond and then it just "catched" by pumping the pedal and all was normal on the drive back home. i shut it off and tried to restart,but again it wouldnt start. ive been driving it to work like that, since it turns on good when cold, and runs without any problems. when i have time i will try to track down the problem, i have a feeling that it is spark related, possibly something causing spark to be weak or out of time. mine should be easier to figure out than yours since mine does not start until the engine has cooled back down for at least an hour, so that gives me a bigger window for testing than your 5 seconds of extended cranking.

fturner
08-13-2009, 07:13 AM
Next time you go to start the car hot, hold the gas pedal to the floor while cranking for a couple of revolutions then take your foot off of it.

Fraser

Motohead
08-13-2009, 09:41 AM
Yep tht's right, my '91 SC still has a Hot start issue, and it's now driving me nuts.. I know i bought this car for a challenge but DAMN!!

Replaced with NEW:
Sparkplug
Sparkplug wires
Fuel Filter
Cam Sensor
DIS module
ECT sensor
TPS (?? I think i did?)

On the car is a '93 PN (Read OE Ford) Crank sensor that looks to have been replaced recently (IE Loom is clean, Wires clean Sensor itself clean), Balancer is looking good with no cracks in the rubber, and spins straight..

Fuel Pressure is good, 40ish KOEO and 30ish KOER (Mechanically 100PSI guage) FP held good, after like 30-45 minutes it was still in the mid 20 PSI range, instanly came up when key was turn to run, and stayed good during cranking and starting..

When Cold the car starts great, sometimes with in a quick hit of the key.. once warm it can take like 5 or more seconds of turning it over to get it to start.. with the odd times it running at around 400rpm, and if left Black smoke will start coming out of the exhuast and it can run like that for some time.. with out throwing a code either!!!! But usually if you press the gas pedal a hair, and it gets up to like 500-600RPMS it'll catch fully and go up to like 1500rpms and settle back down to it's proper RPM like if nothing happened :eek:

Ground issue? Even thou i upgraded the factory grounds (4ga from battery to chassis and chassis to engine along with Battery to Alternator (Ground and Postive))
MAF sensor?? Down side i have no spares unless one from a '89 XR7 will work?
O2 Sensors?? (like it reads those for the first few seconds of running)
ECU itself??

Thanks

Was the ECT you replaced new? If not get a new one.

91 XR7
08-13-2009, 11:00 AM
ECT was replaced with a Brand new Ford piece..

Fraser, i know i've tried pushing the gas pedal some while cranking it over (never to WOT thou:confused:)

Usually i try to start it, it does it typical hot start crank, i open the throttle some (1/2 or so) it still does just cranks over for another few rotations then it finally catches and i instantly let off the throttle it revs up to 1500rpm like normal.. i do not know if it truely did something or it's just coincidence.. since it's still in the same kinda overall time frame as if i didn't push the gas pedal.. but never does the 400RPM black smoke idle thou..

Mam.. one day we'll figure this out :) Either that or i'm personally parting out this thing when the insurance is up :p Hey i need a Parts car to fix up my '91 XR7.. i just hope the rockers in the rear are good.. BAH!!!

fturner
08-13-2009, 11:06 AM
Holding it to the floor shuts the injectors off. I'm just curious to see if its because your flooding out or some other reason.

Fraser

thundermax
08-13-2009, 11:57 AM
You may have a plugged or leaking fuel injector or some type of injector problem. Also may have some carbon buildup on valves.

Without diagnostic testing I can't be for sure, but it wouldn't hurt to run some good injector/combustion cleaner.
If you decide to do that don't use the crap that you pour in your fuel tank; use the one that connects to your fuel rail and turn off the fuel pump.

Silenced
08-13-2009, 12:44 PM
What's your voltage while cranking, while idling low, and when idling normally?

speed95
08-13-2009, 09:05 PM
I had the same problem years ago. I did the flooring it before start and it fired up every time. When I took it to Vernon he said it was a temp sensor. When that one goes out it says it tells the computer that its really cold and to dump more fuel. After it was changed out I have had no problems in years. Dont know if that will work for you but it did for me.

91 XR7
08-13-2009, 10:33 PM
Fraser; I knew what flooring the throttle does during starting :p
After work today after like 3-4 compression strokes it wasn't starting, so i floored it and within like 3 compression strokes it started... There be a fair amount of Stopping tomorrow so i can do more `testing'

How long should the fuel pressure stay good for after the key is off?? dropping like 10-12? PSI in like 30-45 minutes bad?? The injectors had been cleaned and checked (professionally) and even before i stuck them into the intake i installed them onto to fuel rail and powered up the car, jumped the FP turn on lead at the Self test connector, and ran it at that for like 5minutes without a drip.. :confused: Unless for some reason only when they are warm they leak?

Silenced; I can try to figure that out in the next day or two.. I know it's charging in the normal range when running good thou..

speed95; As i stated In the first post, that was one of the Sensors i replace (Ford unit too)

Another thing is, the car does have to sit for like 10-15 minutes (on average) for it to start to do this.. and the longer it sits the worse it gets so it really is a heat soak kinda deal.. I can shut it off and restart right away with no problems.. even after a few minutes..

KMT
08-13-2009, 10:56 PM
With no codes, I'd say plugged cats...

Silenced
08-14-2009, 12:40 AM
Silenced; I can try to figure that out in the next day or two.. I know it's charging in the normal range when running good thou..


Check it please. You're getting too much fuel without good reason. If voltage is low, strange things can happen... When you rev the low idling motor, you are in turn spinning the alternator faster, increasing its propensity to charge the system and correct the voltage (if it is low).

fturner
08-14-2009, 08:26 AM
The other thing that can be happening is that exhaust is being sucked into the intake at shutdown diluting the air/fuel charge at startup unless the car sits for awhile. My car does that because of valve overlap caused by the cam and I can tell when its going to happen by watching the pressure gauge. If it suddenly goes to zero, my next startup needs to be throttle to the floor.... if the gauge gradually goes to zero, then all is well.... if I don't because the car doesn't start right away it gets flooded out. Spin the motor a couple of times with injectors off purges the garbage out and away you go.

As for voltage, the EEC compensates for lower voltage by increasing pulse width to the injectors. If it didn't then the injectors wouldn't be supplying enough fuel at lower voltages.

Fraser

Silenced
08-14-2009, 09:02 AM
The other thing that can be happening is that exhaust is being sucked into the intake at shutdown diluting the air/fuel charge at startup unless the car sits for awhile. My car does that because of valve overlap caused by the cam and I can tell when its going to happen by watching the pressure gauge. If it suddenly goes to zero, my next startup needs to be throttle to the floor.... if the gauge gradually goes to zero, then all is well.... if I don't because the car doesn't start right away it gets flooded out. Spin the motor a couple of times with injectors off purges the garbage out and away you go.His car isn't cammed, so it is very unlikely that this is his case.

I am curious why you need to turn off your injectors though. If you're overlap is allowing exhaust gasses to be sucked into the intake, filling the vacuum, obviously, it's unlikely to start the first few rotations as it is inducting spent combusion gasses from the shutdown. Wouldn't the fuel being injected simply get carried out the exhaust with the spent charge as well? Is there a reason to floor it other than to keep your kitty-cats happy?


As for voltage, the EEC compensates for lower voltage by increasing pulse width to the injectors. If it didn't then the injectors wouldn't be supplying enough fuel at lower voltages.

Fraser What about sensors? Specifically temperature sensors?

fturner
08-14-2009, 09:28 AM
His car isn't cammed, so it is very unlikely that this is his case.

I am curious why you need to turn off your injectors though. If you're overlap is allowing exhaust gasses to be sucked into the intake, filling the vacuum, obviously, it's unlikely to start the first few rotations as it is inducting spent combusion gasses from the shutdown. Wouldn't the fuel being injected simply get carried out the exhaust with the spent charge as well? Is there a reason to floor it other than to keep your kitty-cats happy?

What about sensors? Specifically temperature sensors?

The injector timing on our cars have the injectors firing at 380 crank degrees at startup and idle etc, the exhaust port is pretty much closed by then so with a dirty air/fuel mix and excess fuel sitting in there you have a bad startup that results in black smoke coming out.... hence the need for "purging". The stock cam still has some overlap as well, and he could have leaking valve seats etc. My car its the cam causing the issue.

All the sensors run with 5 volts supplied from the EEC. This is done by a voltage regulator in the EEC so at 8 volts to 15 volts, its 5 volts coming out.

Fraser

Silenced
08-14-2009, 09:52 AM
The injector timing on our cars have the injectors firing at 380 crank degrees at startup and idle etc, the exhaust port is pretty much closed by then so with a dirty air/fuel mix and excess fuel sitting in there you have a bad startup that results in black smoke coming out.... hence the need for "purging". The stock cam still has some overlap as well, and he could have leaking valve seats etc. My car its the cam causing the issue.

So it's more personal preference to evacuate the system rather than seeing a partial burn coming out the exhaust?

His 400rpm rich idle can go on "for some time".

Given that the issue you are describing only happens at the immedate startup of the car, could it still be the case in his situation even? I would think the partial mixture would be evacuated rather quickly.

rickbtbird
08-14-2009, 10:02 AM
Have you ever noticed the tac being dead and any warning lights on the dash when you crank and no start?

91 XR7
08-14-2009, 11:05 AM
His 400rpm rich idle can go on "for some time".


I myself would think if a car is floored.. if it does finally `catch' and `run' that it would eventually clear itself out and run typically.. SPECIALLY on a Fuel injected car.. i know the IDF Weber based engines we deal with at work can clear themselves of a flooded situation, in time..

But when this car starts up and runs @400 or so i can get out.. walk around the car a few times seeing how bad the smoke is out the exhaust (It doesn't Bellow large quantities of black smoke but it's there, and has a rich smell too it) then under the hood wiggling things... the very last time i tried opening, or was it closing? SC bypass.. and the car stalled.. :) took abit of starting again but when it did it did it `normally'

Fraser; Yah the Vacuum Gauge on the car, just SLOWLY goes back to 0 like any other SC i've driven, and same with my '89..
But yah this car is 100% stock other then the Front speakers and CD-player and the crudely installed replacement cats..


rickbtbird; When cranking everything is as normal.. turn the key to the run position.. everything lights up and then shuts off as normal.. turn the key to the run position the Up shift light goes off with in like 2 compression strokes.. And even with the lastest letting it run for like 2+ minutes.. and throws not a SINGLE code.. which you'll think idling rich at like 400RPM, for that long WOULD throw a code


I just wish i could bolt on the `off road' front Y-pipe i have for my '91 XR7 to it.. least it doesn't have Cats to melt down.. but it's also 2.5" piping at the "collectors" :(

fturner
08-14-2009, 11:54 AM
His 400rpm rich idle can go on "for some time".


So does mine.....

Oh well, it was just a thought.

Fraser

rickbtbird
08-14-2009, 12:26 PM
I myself would think if a car is floored.. if it does finally `catch' and `run' that it would eventually clear itself out and run typically.. SPECIALLY on a Fuel injected car.. i know the IDF Weber based engines we deal with at work can clear themselves of a flooded situation, in time..

But when this car starts up and runs @400 or so i can get out.. walk around the car a few times seeing how bad the smoke is out the exhaust (It doesn't Bellow large quantities of black smoke but it's there, and has a rich smell too it) then under the hood wiggling things... the very last time i tried opening, or was it closing? SC bypass.. and the car stalled.. :) took abit of starting again but when it did it did it `normally'

Fraser; Yah the Vacuum Gauge on the car, just SLOWLY goes back to 0 like any other SC i've driven, and same with my '89..
But yah this car is 100% stock other then the Front speakers and CD-player and the crudely installed replacement cats..


rickbtbird; When cranking everything is as normal.. turn the key to the run position.. everything lights up and then shuts off as normal.. turn the key to the run position the Up shift light goes off with in like 2 compression strokes.. And even with the lastest letting it run for like 2+ minutes.. and throws not a SINGLE code.. which you'll think idling rich at like 400RPM, for that long WOULD throw a code


I just wish i could bolt on the `off road' front Y-pipe i have for my '91 XR7 to it.. least it doesn't have Cats to melt down.. but it's also 2.5" piping at the "collectors" :(

I got to tell you, it sure does sound like you have a nasty vacuum leak somewhere. Check your IC tubes and connections.

Silenced
08-14-2009, 12:35 PM
So does mine.....

Oh well, it was just a thought.

Fraser

On my cougar, I have a setting for startup enrichment, which I have adding additional fuel upon hot starts if RPMs are below 300.... Is there a smiliar setting on the stock computer maybe?

91 XR7
08-14-2009, 12:45 PM
I got to tell you, it sure does sound like you have a nasty vacuum leak somewhere. Check your IC tubes and connections.

Recently went through them all.. And everything been checked and resealed..
Holds at idle like 20 inches of Mercury and i have yet to hear what can sound like a boost leak yet, even up to a indicated 11psi (it has never gotten higher then that since i owned it.. and this problem started a year after i got the car) all the way to like 4500rpm going up a hill

When i had the SC off to replace the injectors (this problem was there BEFORE this job) and redoing the snout seal, I replaced every hose that was remotely questionable.. and everything is hooked up right..

MAM
08-14-2009, 07:02 PM
well i figured mine out. it was a bad coolant temp sensor. i checked my ECT with a voltmeter and i had good 5v ref. signal return voltage however with engine fully warm was 2.23 volts, too high, this equals about 110*F. the resistance on it was about 30k ohms with engine fully warm, again, way to high! changed it out with cheapie sensor and now the signal voltage with engine fully warm is about .6v. all is well again...for now. also i should note that mine did not start even when i floored the gas pedal to shut down the injectors, i had to wait around an hour before itll restart.

91 XR7
08-16-2009, 12:26 AM
Mam; As stated above i've replaced the ECT sensor with a brand new OEM one.. and it seem to be with in spec..

Silenced; Well Charging it's around 13.8Volts, Key off for abit it's like 12.2Volts, Cranking it's @10.5 Volts.. This is the battery that came with the car when i bought it, and it was ran dead because of a stuck ABS pump relay a couple of times and i had to jump start it to get it to start.. Ran it for like 30 minutes.. and it's started every time since then.. even being parked at my friends place for like 2 months with out being started when i first got the car (from dealership towed to my friends to be parked )

Random; When it does the hard start thing. It does have spark.. So it can't be that.. i think, unless it's firing at the wrong time (plug wires are correct)
I've been ask by two people to check the plugs thou to see what they are like.. Mostly if it is having a hard time starting, to see if they a fouled or not.. the other mostly to see if there may be a Head gasket issue.. (Both mechanics, later being a Ford Tech?)
also TPS voltage is .89 Volts in the idle position..
Now what kinda voltage should i be seeing for the MAF sensor (Engine off and at Idle), MAP sensor (at sea level since it's basiclly just a switch??) and possibly IAT??
What kinda duty cycle would an injector have at start up and at idle? Also need to find a way to hook up an LED to an injector or two

Also yesterday driving around, I smelt raw gas while driving.. So I'm going to have to look into that.. it may of been random from a car in front of me.. So we'll see..

J dot Miller
08-16-2009, 03:47 PM
You should get a battery load test done. Many shops will do the test for free! :eek:

91 XR7
08-16-2009, 09:48 PM
the battery shop we deal with at work do free testing, and even come to pick it up.. So we'll see.. So far a few people have mentioned about the battery... So.. Also i have no what kind of CCA and CA it has.. I havea semi newer (3 year old) 675CCA batery in my '89 XR7 that i can try.. but i rather have the correct 800cca one??

Also on a jack getting at the spark plugs ain't fun.. even after liek 2 1/2 hours of sitting it did it's normal hard start thing.. and just as it it caught, i shut it off..an was able to get to #1 plug, which seemed to be good.. I just couldn't get at #3 which i was told to check or and on the drivers side :( Saddly after doing a oil change on it.. then running it abit.. some good reving too. shut it off for 30 minutes or so, and it did it's 400RPM smokey ilde, Vacuum guage was bouncing between from like 1-2 Inches to 0 the whole time.. I know the ECU commands full open on the IAC so??

Well i got too Sept 18th to get this figured out.

Paul93SC
08-17-2009, 06:53 PM
Another thing is, the car does have to sit for like 10-15 minutes (on average) for it to start to do this.. and the longer it sits the worse it gets so it really is a heat soak kinda deal.. I can shut it off and restart right away with no problems.. even after a few minutes..Mine does the same thing on occasion. It happens mostly in the summer, and usually at a gas station (10 minute stop).

I don't think you have a problem with your car. I believe what is happening is vapour-lock in the injectors. Once sitting for a few minutes after driving, the gas trapped inside the injectors tends to boil. What I do to get by this is to hold the gas pedal about half way down and crank.. and at 'just' the moment the engine catches, I let off. If you get the timing right you can eliminate the RPM flare-up :).

91 XR7
08-17-2009, 09:35 PM
Yah.. that make sense to the most part, but throw in that the car sometimes when it catches (and it did yesterday) starts and idles at like 400-500rpm and starts smoking out the tail pipes.. :mad: So i do not think it's a Vapor lock kinda thing.. also Vapor lock on a FI engine is kinda odd.. since the `vapor' should be out of the system with in the first 1-2 seconds of turning it over..

I had a Mechanic tell me `Oh older cars have issues starting, i would just get use to it' Excuse me.. But i also have a '66 comet, It can sit for a year, just add in some gas to the float bowl, hook up a good battery to it, pump the gas pedal twice and turn the key and it'll start up almost instantly and Idle nice.. This thing is a Fuel injected Car, it should fire up right the first time, and every time

Also on sunday.. it still had an issue starting after say 2-3 hours of sitting.. So.. Also is the SC engine from the underside suppose to sound like it's a Diesel??:o

91 XR7
08-19-2009, 09:56 PM
Well tonight.. I went to start the car to go pick up the little lady, crank crank crank crank crank as as soon it started to catch i let off the key and it idled roughly at like 300-400rpms (Battery light was even flickering) after a few seconds of that.. i eased into the throttle abit and it revved up to like 1200rpms look in the mirror and it was the smoke that came out seemed more white this time around.. But being dark, with orange lighting (sorry forget of the name of those kinda street light bulbs :( )

It does idle with a little bit of a lumpiness too it.. But i have yet to notice a lost of coolant, or coolant in the oil, or oil in the coolant :(

I know Ford did have the whole intake system off the car at one time (right down to the heads) I do not know why thou.. But off idle the car performs very well.. even en route to the lady.. it was a blast to drive.. :)

So head gaskets about to pop?
Head(s) cracked? (do have another set thou)
Intake to Head gasket (had that one go on my '91 XR7 5.0L)