Hesitation and lack of power when cold

rideapony · Jun 30, 2009

Maaan I don't know!!! but just for my own peace of mind I did all the measurements again and this time I got the same readings at the computer's connector and at the sensors connectors; those readings were from as low as 0.05 to close to 0.9 Volt. The only thing I did was to unplug/plug the sensors harmess connector by the driver side strut tower.

One thing that really confuses me is the different wrie colors the computer's connector has, for instance wire for pin 29 is red/blue and it is the same color at the driver's side sensor's connector and comparing the diagram color codes and and phisical colors at the main harness I can see soo many differences

Any ways I'm not sure how to proceed from here!!!

Thank you, Nick

cheese_05_70 · Jul 1, 2009

Well i got a 306 with an HCI and it does the same thing I havent checked the voltage for oxygen sensors (which are new). I had my car dyno tuned helped power wise but not on cold start. No codes checked them. Mine runs good when its warm but runs like crap when cold. Have you figured anything out with it yet? Is it just the nature of some motors? Someone should be able to figure this out there is enough of us that have the same problem.

Thanks,
Colby

ID89GT · Jul 2, 2009

cheese_05_70 said:
Well i got a 306 with an HCI and it does the same thing I havent checked the voltage for oxygen sensors (which are new). I had my car dyno tuned helped power wise but not on cold start. No codes checked them. Mine runs good when its warm but runs like crap when cold. Have you figured anything out with it yet? Is it just the nature of some motors? Someone should be able to figure this out there is enough of us that have the same problem.

Thanks,
Colby

Sounds like a vacuum leak. When I had mine checked, I had 3 good sized vacuum leaks. Had all the same problems that you guys are having, runs really crappy when cold, warms up and it drives fine. After fixing the 3 leaks, I would start it up and it would run good right off the bat. When the car is cold it runs in open loop and the o2 sensors are not doing anything yet, so all the extra air from the vacuum leak is making it run lean and the computer has no idea about it and it runs crappy. Then once it warms up and goes into closed loop mode the o2 sensors see the extra air coming down and correct it by adding more fuel, so it begins to run like it should be, although really its not cause fuel trim numbers are higher than they should be.

rideapony · Jul 2, 2009

Thanks Nick for sharing tips.

I think at this point I'm going to forget about anything else and focus 100% my efforts to find a vacuum leak. I think the O2 sensors are switching fine as well as the rest of the sensors. So I'm going to really inspect all joints at the upper to lower, lower to heads and lifter valley...So if there is a vacuum leak I'm determine to find it

In a different topic which clutch and flywheel you guys recommend? I want some good performance but also I want durability and reliabilty.

The Spec-2 that I have is just bad. At idle it sounds like a rocks tumbler!!! And I think that's what causing a high speed vibration (Over 75 mph)

Thank you all, Nick

ID89GT · Jul 3, 2009

I bought the King Cobra clutch and it has served me well, as for a flywheel, the Ford Racing one for like a hundred bucks should serve you just well. I have just an OEM ford one and it does the job

rideapony · Jul 3, 2009

Like i said I'm going to focus entirely on finding a vacuum leak and will post any findings.

As for the clutch, I may try the king cobra and will see how it performs as far as flywheel I have the ford racing cast iron which will be cearefully inspected when replacing the POS spec-2.

Thank you, Nick

rideapony · Jul 4, 2009

FINDINGS!!!! I took her to a mechanic for a vacuum leak using a brand new smoke machine and I was really surprised by the results:

* No vacuum leaks were found in any area of the both intakes

* A big vacuum leak was found at the EGR valve but to my surprise it was not leaking at the diagram (I knew that because I checked that and it holds vacuum without leaking) instead the smoke was coming in great amounts thru the small shaft that opens and pintle. I never though about that posibility.

The EGR valve is not that old but i ordered from Rocky Auto, they claim that they are OEM which I start doubting. The mechanic suggested me to buy the valve from Ford because he said he don't trust the aftermarket ones from autoparts.

* There were also a very faint smoke leaks at the top thru the thottle plate shaft out of the TPS and thru the throttle body studs, but those were just faint and don't think those will affect idle or performance.

Did anybody had experienced this before?? Is this leak normal??

Next week I will go to the Ford dealer and buy the EGR valve. I went today but it was closed.... Darn it!!!! It is a holiday!!!!

HAPPY 4th OF JULY EVERYONE!!!!!!

Nick

ID89GT · Jul 4, 2009

All leaks are unmetered air entering. I would fix ALL of them.

Lawbreaker5.0 · Jul 6, 2009

where exactly was it leaking at the egr? pic? and i think the noise you hear by the the bellhousing is the the throw out bearing. replace it just to be sure when you do the clutch

rideapony · Jul 7, 2009

Well I don't have a picture of the EGR but the leak is coming thru the small shaft, the one that pulls the pintle. If you look thru the holes on the EGR valve you will see this small likle an 1/8" thick shaft.

Well yesterday I called a Ford dealer but they don't have the valve in stock and it cost around $300.00 WTF!!! This is unreal, they charge whatever they want!!!

When I got home I applied a generous layer of high vacuum grease to the EGR shaft. This grease is good for temperatures well over 200*C. I used the grease on all the leaks I found during the vacuum leak smoke test. We use this grease at work on high vacuum precision equipment.

Also I found that the TPS was at 0.99 V but if I let the throttle go slowly to idle position the voltage was hanging over 1.0 Volt. So I adjusted it to get about 0.98 V at slow resting throttle plate (Worst scenario) I have to mention that I'm using a good digital meter.

Well this morning at cold start she was much happier (and me too), didn't have backfire and there was hardly no lagging between shifts.

I hope these tips help others dealing with the same issues. I'll keep working on it to better the cold start conditions maybe disconnect the battery so she can adapt to the new conditions, etc. and will post more good results (I hope!!!)

Nick

Lawbreaker5.0 · Jul 7, 2009

are you gonna buy the 300 dollar egr valve?

rideapony · Jul 8, 2009

I don't think I'll buy that, it is too expensive. I believe the OEM EGR has cast aluminum body and looks more sturdy the part number is E7AE-9F483-A2A.

I noticed that mine is working fine since I applied the vacuum grease on the shaft. Overal she is running much better.

The other thing is bothering me is the temperature. On hot days it goes up to about 205 deg. I have a 3 row brass radiator, Mr Gasket 180 deg balanced thermostat, Taurus elect fan on high with an FK15 variable DC controller. Could be the under drive pulleys? I used to have a griffin aluminum radiator and ran with the same issues.

What can I do to solve this issue?...Bigger radiator?better water pump? go back to stock pulleys?

Thank you, Nick

jrichker · Jul 8, 2009

Go back to stock pulleys. Underdrive pulley are not the best plan if you live anywhere it gets hot.

Lawbreaker5.0 · Jul 8, 2009

yeah i have problems with my car starting to creap up on hot days, higher than normal (3/4 of the way) until i get moving.

i also have under drives., but my condenser is pretty jacked up and clogged on mutiple places so that could be contributing to my problem.

87GT40 · Jul 8, 2009

something you might want to try is a spacer on your intake. i dont know if it will change with the u/d pulleys or not. i live in virginia and even in 90* days my car only runs @ 190 max. thats sitting still. while driving it comes down to 180 or so.

rideapony · Jul 9, 2009

I thought it was too good to be truth!!!!
I'm back to square one. The issues at cold start still there so I'll be working on finding maybe another conditions that might be contributing to that, like a vacuum leak. Today I'll be re-torquing the lower intake manifold to see if that helps.

As for the temperature issues, yesterday I changed the crank and water pump pulleys back to stock. I will keep my eye on the temp on my way home after work.

The only pulley I didn't change is the alternator (200 Amp), do you guys think there will be any issues with that? will the alternator over-spin with the small pulley? should I use the stock one instead (bigger)?

I've been noticing a burning smell when turning the heater on also I've been missing just a bit of coolant, most likely the heater core has a pin hole and just steam comes out it because everything is dry under the dash. What a nightmare to replace the heater core, HA!!!

Nick

tcossair · Apr 26, 2010

Did you ever solve this issue? I have almost the same exact symptoms on my 2005 Mustang GT :-(

87GT40 · Apr 27, 2010

try cleaning your maf sensor i was having this issue also and that was the culprit.

Hesitation and lack of power when cold

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