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Discussion Starter · #1 ·
Hey guys, my car has a problem where when it heats up it runs pretty bad. It feels like theres a lot of missing power.
When its cool outside it runs like a champ, feels 150% better. It's really weird. When its acting up it'll smoke a little black if it's revved, and sometimes backfire (if its revved standing still). It hesitates when you get on it. It feels like the car has to catch up to itself.
I have new o2 sensors, plugs, wires, distributer cap, rotor, ECT and ACT sensors. The MAF was also cleaned. The car will not run without the MAF sensor. I just put seafom through the top-end to clean it out. I'm pretty sure there isn't a vacuum leak because most of the time I have a steady idle. Please, anything you guys can advise would be great. I had a mechanic look at it and he couldn't figure it out. Fuel pressure is good as well. No codes, and the car is 100% stock. It's weird.
Thanks guys,
Joe
 

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I'm guessing that either the fuel pressure is low enough that it's dropping noticeably with heat, or that it's the TFI or pickup module in the distributor - they will malfunction in the heat, but work better when cool. I'd check for a fuel pressure drop, and if that's normal, it'd be really nice to have a known good dizzy to drop in it for comparison's sake, as there's not a good surefire way to test the pickup module. You can test the TFI, though.
 

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Discussion Starter · #3 ·
Well I was also thinking the TFI. But its not in the dizzy in my year correct its under the intake ducting. How do I test it? Maybe I should just buy one for like $15 from autozone and try it. The distributer might also be the culprit, but I don't really know if I wanna shell out $100 to test it.
 

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Discussion Starter · #4 ·
Hrm,
If I check fuel pressure while at a standstill should it be 32 at idle? And 39 at wot? Should I check it while driving so that there is a load on it?
 

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Discussion Starter · #6 ·
STINGREY said:
dude; check the fuel pressure with no vacum standing still,about 42
Ok, im a bit confused about the vacuum. All I did was plug a gauge into the shrader valve to get a reading. Will this give me inacurate results? What vacuum line do I unplug and what do I do with it?
 

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Ok, not to nock on fords, its all i own, but mustangs in preticular drive alot better when its cold out. This time of year, getting down into the 50 and 60 it feels like its soo much faster. However, you stated that it backfires and smokes when its hot, so I dont think the temp is your only problem. Check the gap on your plugs, if you havnt allready, when you get the plugs out eye them up and smell them to see if you see/smell anything out of the ordinary. Its so hard to say though, it could be alot of things, however I dont suggest going out and buying parts to see if thats what you need or not, because by the time youre done you could end up having alot of money into it. One other thing, when your car is runing bad look at it and see if you have a bad miss. Good luck and dont get to stressed
 

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Discussion Starter · #8 ·
Joes 5.0 said:
Ok, not to nock on fords, its all i own, but mustangs in preticular drive alot better when its cold out. This time of year, getting down into the 50 and 60 it feels like its soo much faster. However, you stated that it backfires and smokes when its hot, so I dont think the temp is your only problem. Check the gap on your plugs, if you havnt allready, when you get the plugs out eye them up and smell them to see if you see/smell anything out of the ordinary. Its so hard to say though, it could be alot of things, however I dont suggest going out and buying parts to see if thats what you need or not, because by the time youre done you could end up having alot of money into it. One other thing, when your car is runing bad look at it and see if you have a bad miss. Good luck and dont get to stressed
When the car first starts up its a beast. After a couple minutes or longer of driving (usually dependant on how hot it is outside) It starts to hesitate badly like its gotta catch up to the pedal. The RPMS dont really go anywhere and then they jump up. Its scary pulling out of an intersection in a tight situation because of this. It will not go anywhere and then go. I definitely think its getting too much fuel and choking itself, but why only after it heats up?
 

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Have you tried pulling the codes ?
 

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I got my TFI at Advance Auto Parts. Believe it or not, it has a lifetime warranty ($31 out the door). When my TFI went, the car just died on me :)worship at home). I think the pickup is more likely to show problems when hot, than is the TFI. (I think) the TFI either works or doesn't work. Fuel pressure sounds about right for stock.
Were the ACT and ECT replaced as a result of this problem?
Also, how are your battery cables? They'll malfunction in the heat when worn out.
 

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Discussion Starter · #12 ·
meangreen92 said:
I got my TFI at Advance Auto Parts. Believe it or not, it has a lifetime warranty ($31 out the door). When my TFI went, the car just died on me :)worship at home). I think the pickup is more likely to show problems when hot, than is the TFI. (I think) the TFI either works or doesn't work. Fuel pressure sounds about right for stock.
Were the ACT and ECT replaced as a result of this problem?
Also, how are your battery cables? They'll malfunction in the heat when worn out.
Hm, dunno about the battery cables. They're clean on the battery. ECT/ACT were replaced but didn't help.
 

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If I was sure that all of the sensors were ok, I would then go through the engine compartment and try to look at every ground and connector I could find. Bad connections cause even more resistance when hot.
Then, I would try to find a way to check the fuel pressure under load and especially when the car is acting up. I would also try to swap in a known good dizzy (without actually buying one, of course). The TPS could also be causing this.
You may have better luck getting this diagnosed in the SN-95 forum, maybe someone else has had this trouble.
 

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Discussion Starter · #15 ·
Okay well today I pulled the whole drivers side spark plugs and they all looked normal. I also cleaned all the salt and pepper connectors with electrical cleaner. I then cleaned inside the TB. There was a wire exposed on the TFI like where is was stripped and I taped that up. The distributer cap looks good. My coolant scared me for a second because it looked brownish but I think its just rust it doesn't smell like oil. It's really dirty in there also. I guess I should flush it. The needle always sticks straight upwards when the car is warmed. (Temp gauge).
Do my problems sound like a blown HG? Please dont say yes!
I don't know what else to do.
BTW I don't know if the spark plugs looked lean or whitish (lean) They are new plugs so I don't know if it would be there that quickly.
 

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Discussion Starter · #16 ·
Okay here is something else! I may have found the culprit.
One of the wires was leaning against the egr. It was all black where it was touching. Could this be the culprit? When it heats up it affects the wire?
The bad news is i smelled my exhaust and it does smell sweet. :-(. But no smoke.
Ugh heres more bad news, there was smoke coming from somewhere in the engine compartment, looked to be behind the intake. I couldnt figure out where it was coming from because it was dark. Blown HG? Intake gasket?
 

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Synned said:
Ugh heres more bad news, there was smoke coming from somewhere in the engine compartment, looked to be behind the intake. I couldnt figure out where it was coming from because it was dark. Blown HG? Intake gasket?
Hopefully just the intake. Maybe you should do a compression check, when warm.
 

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Synned said:
You think its the intake gasket?
I'd really have to see it. Getcha a flashlight and a small mirror - I think autozone sells those little mirrors that are mounted on the telescoping masts. With those two items, you should be able to make the determination.
 

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Discussion Starter · #20 ·
meangreen92 said:
I'd really have to see it. Getcha a flashlight and a small mirror - I think autozone sells those little mirrors that are mounted on the telescoping masts. With those two items, you should be able to make the determination.
Okay, well I heated the car up to the point of running crappy and passed the cylinder balance test! At least it isn't a HG! :). But the exhaust smells very very sweet. I had someone else smell it to make sure I wasn't crazy. Yesterday for some reason out of nowhere there was smoke coming from somewhere in the engine bay, looked to be behind the intake. It was white smoke (maybe antifreeze burning)?? I couldn't tell where it was coming from.
So my guess is its the gasket?
 
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