trying to fix 3 different problems

[sharky207]

I want to sell my truck and i refuse to put it up for sale with problems. So i would like to fix them all and put it in the auto shopper.

Problem 1. My tach, speedo, and odometer all stopped working at the same time my low turbo coolant light came on (dim). for a while they were coming on randomly until eventually they stopped working. Every single time the work the low turbo coolant light goes away.

Problem 2. turn key...click,click,click. I've replaced the purple wire, and the starter but they did nothing. I replaced the ignition switch which caused the click, click to go away for about a month.

Problem 3. I've posted about this before. When i start my truck up after sitting for a while it usually wants to stall. It stumbles, shakes, and i give it gas until it finally catches itself and then its fine. When it does this there is black gas smoke pooring out of the exhaust. Especially since i have no cat. Ive had it hooked up to various snap-on tools and it shows no codes, and no odd values. I've already replaced iac, ecm w/ chip, egr, map sensor. I ran a fuel pressure test and it keeps pressure in the line. I did the bike tube vacuum test and it seemed to have no leaks.

I would really like to do this myself but im growing restless. Does anyone know a good place to bring these trucks near me. Im in central Jersey.

 

[RS25.com]

Don't know of any shops, but if you want some guesses, here are mine:

Dash - you've got a bad ground in the wire harness.

Click - bad starter solenoid.

Idle - black smoke is indicative of too much fuel being burnt, so do you have any add-ons (RRFPR) that would allow too much gas in? You might also check the usual supects such as EGR valves and things that are related to emissions and fuel delivery.

Hope that helps!

-James

 

[canadian]

Re: trying to fix 3 different problems

Problem 1. My tach, speedo, and odometer all stopped working at the same time

check the white box that's attached to the ecm. see if the wires are loose there. you'll have to get up under the dash to pull it out.

 

[myclone]

Re: trying to fix 3 different problems

Problem 1. My tach, speedo, and odometer all stopped working at the same time my low turbo coolant light came on (dim). for a while they were coming on randomly until eventually they stopped working. Every single time the work the low turbo coolant light goes away.

This is a connection/ground problem. The dim low turbo coolant light gives that away. The light is supplying current to something else instead of that load getting it from its normal source. Its like putting a light bulb in series with another light bulb then plugging that whole mess into a socket. Both the second light works cause the current is flowing through the first bulb (which is lit too). Kinda hard for me to explain but thats basically whats going on.

Problem 2. turn key...click,click,click. I've replaced the purple wire, and the starter but they did nothing. I replaced the ignition switch which caused the click, click to go away for about a month.

Where did you get the starter and ign switch? Those two items if sourced from the local chain parts store have a high failure rate cause they are cheaply made or rebuilt. Ive bought a starter from them and had it crap out only weeks later or not work at all when it was put in. Hell, Ive had to take NEW chain store starters back 2, 3, or 4 times to get a good one. The ign switch Id buy from GM as the chain store electrical parts are junk IMO. I have a box FULL of sensors and other misc chain store electrical parts Ive pulled off of cars Ive worked on because they didnt work or worked just enough to make the car run like ass.

Problem 3. I've posted about this before. When i start my truck up after sitting for a while it usually wants to stall. It stumbles, shakes, and i give it gas until it finally catches itself and then its fine. When it does this there is black gas smoke pooring out of the exhaust. Especially since i have no cat. Ive had it hooked up to various snap-on tools and it shows no codes, and no odd values. I've already replaced iac, ecm w/ chip, egr, map sensor. I ran a fuel pressure test and it keeps pressure in the line. I did the bike tube vacuum test and it seemed to have no leaks.

Thats a classic low MAP sensor vacuum signal symptom. Are you SURE there are no vacuum leaks? Especially in the MAP vacuum line circuit. What about the fuel pressure? You said you did a test so what is the actual fuel pressure? Super high fuel pressure would cause a rich condition too. Do you have a adjustable fuel press regulator? Is it functioning correctly?

Lastly, whats the coolant temp sensor saying according to the scan tool you said you used? A bad coolant temp sensor could be telling the ECM that the engine is colder than it really is and the ECM is delivering more fuel than needed (works like a choke on a carb).

 

[sharky207]

I have a stock fuel pressure regulator on my truck. I forget what my exact fuel pressure was but i believe somewhere around 43. I've read up on that and found that it's where it should be. I forget what my values were for map and coolant sensor but a few mechanics and the actual snap on scanner said they were fine.

the starter and ignition switch are both from napa. Since the ign. switch eliminated the problem for a period of time i will replace that again.

As for my electric problem I am going to need someone that knows what they are doing (not me)

Is there any pictures online of how our vacuum lines should look. Maybe what size lines, t's, etc.

thanks

 

[SY2932]

Vacuum diagram: http://www.syty.huryde.com/html/supplement/vacuum.html HTH's

Mike Campbell

 

[AXXE]

What chip are you using? I kind of remember you saying you had a bigger cam put in on your rebuild.

 

[Sy#2373]

I had the same problem last year.
Run rough till it warmed up, never set a code and could not find anything on the scanner out of wack.
It ended up being the EGR control soleniod, the EGR valve was being held open all the time.
My chip has the EGR disabled, so i never thought that it would be a problem with the EGR valve.

Tim Knaebel
Sy#2373
1972 Nova SS (7.62 @ 186 mph)

 

[sharky207]

I have a brand new stock ecm and chip. I've replaced the egr before but not the sensor. I didn't even know there was one. Where is the sensor for the egr and how much do you think it is?

Its no secret that i dont know what im doing.