hard cold start
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Elder User
Joined: Mar 2004
Posts: 759
Likes: 1
From: mohave valley, arizona
hard cold start
im having a problem lately with my 90 4.9 starting when cold. i ran the codes and get a 11. i just replaced the EGR valve last week but it was starting to start hard for about a week before that. before i replaced the egr i got a code of 32 which the book i have said EGR and the vacuum line going to it was popping off. i checked it with a vacuum gauge but it held a vacuum. a mech. told me that it was still leaking past the diaphragm and with the code i went ahead and replaced it. still it starts hard when cold but fine after it starts. i also checked the fuel pressure running and not running and its good and held. i also checked for vacuum leaks but nothing. and ideas what else to look for. thanks
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Elder User
Joined: Mar 2004
Posts: 759
Likes: 1
From: mohave valley, arizona
i checked that out and its fine. starts fine and idles great when warm. but now getting worse when cold. starts then dies, restart and dies then starts and warms up and is fine. fuel pressure is 50 psi with key on and holds then 50 psi when running. code is 11 which says is everything is working right. switched from one pump to the other and same thing. wish it would give me some kind of code for at least a starting point. im thinking elect. but wouldnt that give a code. im stumped.
Post Fiend
Joined: Jan 2005
Posts: 8,402
Likes: 10
I am not an EFI expert but your fuel pressure seems too high to me.
Pull the vacuum pipe off the Fuel Pressure Regulator and look for signs of gas in the pipe, if you find any then replace the FPR. I think, if it was me, I would replace it anyway.
Pull the vacuum pipe off the Fuel Pressure Regulator and look for signs of gas in the pipe, if you find any then replace the FPR. I think, if it was me, I would replace it anyway.
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Elder User
Joined: Mar 2004
Posts: 759
Likes: 1
From: mohave valley, arizona
well i checked the coolant temp sensor this morning. 70 degrees outside. have 35.0 on 200K scale. book calls for 58,750 to 40,500 ohms. 35.0 on 200K would be what. i dont really know how to convert it, digital meter.
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Elder User
Joined: Mar 2004
Posts: 759
Likes: 1
From: mohave valley, arizona
ok i checked and it seems that 35.0 on the 200K means that i have 35,000 ohms. the book calls for 40,500 to 58,750, would that be enough to cause it to start hard.
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Post Fiend
Joined: Jan 2005
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Sorry for the bad advice on the FPR.
Acording to fordfuelinjection.com for 70degrees your sensor in reading right. If you go to that site and click on ECT it will give you what it should read at other temperatures. You could put it in boiling water (212 degrees) and see what it measures then to confirm good or bad.
Acording to fordfuelinjection.com for 70degrees your sensor in reading right. If you go to that site and click on ECT it will give you what it should read at other temperatures. You could put it in boiling water (212 degrees) and see what it measures then to confirm good or bad.
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Thread Starter
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Elder User
Joined: Mar 2004
Posts: 759
Likes: 1
From: mohave valley, arizona
well im back to square on. replaced the coolant temp. sender and the IAC. checked all the vacuum hoses and no leaks. only code is 11. have great fuel pressure, key on and running. also seems to surge a little while cursing.
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Elder User
Joined: Mar 2004
Posts: 759
Likes: 1
From: mohave valley, arizona
checked the pressure this morning when cold, 50 psi and holding. tried to start it and it seems to be getting worse, really hard to start, but once started i checked the fuel pressure again and it was a little over 50 psi, i then disconnected the vacuum line to the regulator and the pressure went up. still i have to start it and try to keep it running untill it warms up. once warm it idles like new. i have replaced almost ever sensor except the O2 sensor. really dont know where else to look, it would just be a guessing came. guess i could just keep on replacing stuff. maybe the distributor module. cant figure why it idles so good good when warm, has to be something to do with the cold start system. i dont know, maybe the PCM.
Post Fiend
Joined: Jan 2005
Posts: 8,402
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Beats me. One other thing you could do is go to fordfuelinjection.com and click on ECT and use your volt meter to back probe the sensor wires with key "on" to make sure you have the correct voltage as given in the temperature/voltage chart.
