350 tbi flooding

[Jims86]

http://www.obd2allinone.com/sc/toplevel.asp?cat=2 this is the cable i got. i put the chip where it said to put it.

Ok, i dont see that chip on the site. does that go between a and b? if so, go ahaed and tak it out so we can just read data. that chip in diagnostic commands 1000rpm idle and self test.
I am really curiouse about the iac right now, and I am trying to figure out why its opening enough for a bus to drive through.

 

[don]

the chip can be installed 4 different ways or without chip at all. the way i have it, tunerpro shows "diagnostic switch in shorted field test mode". i tried moving it and it will change to say "diagnostic switch in 10k aldl mode". i tried it all different ways and without it and idle dont change at all.

 

[Jims86]

the chip can be installed 4 different ways or without chip at all. the way i have it, tunerpro shows "diagnostic switch in shorted field test mode". i tried moving it and it will change to say "diagnostic switch in 10k aldl mode". i tried it all different ways and without it and idle dont change at all.

Well dangit! ok, next thing....go ahead and set the fuel pressure to 9 lbs, and see if that changes anything.
At this point i am pretty sure there is nothing wrong with the Engine control system.
so, the timing is set at 0* right?
When you did the minimum idel air proceedure, the iac did close all the way, right? no air sucking through it? what rpm were you abl to get it down to?
have you owned the truck since new?
sorry for all the questions, I am searching high and low to make sense of this.

 

[89Suburban]

Well dangit! ok, next thing....go ahead and set the fuel pressure to 9 lbs, and see if that changes anything.
At this point i am pretty sure there is nothing wrong with the Engine control system.
so, the timing is set at 0* right?
When you did the minimum idel air proceedure, the iac did close all the way, right? no air sucking through it? what rpm were you abl to get it down to?
have you owned the truck since new?
sorry for all the questions, I am searching high and low to make sense of this.

Jim, they make an aftermarket in line pressure gauge for TBI that you can leave on the truck, like the Holley ones for carbs?

 

[Jims86]

Jim, they make an aftermarket in line pressure gauge for TBI that you can leave on the truck, like the Holley ones for carbs?

You can get a brass or bronze spacer fitting and tap it on a drill press for a gauge attachment, then install it in line like the gauge you used.

 

[89Suburban]

You can get a brass or bronze spacer fitting and tap it on a drill press for a gauge attachment, then install it in line like the gauge you used.

I figured there had top be a cheaper way out than that 300 dollar test kit. We should get a write up done on it with part numbers, I think that would be a hot mod for many TBI members here.

 

[don]

i have had the fuel pressure as low as 8 lbs. it floods a little less but ran bad after it warmed up. i have checked the timing. the idle air was adjusted after it had reached operating temp. so i didnt hear the iac sucking air like when its cold. i was able to get the idle down to 500 and then when i pluged in the iac it went back up. i didnt buy the truck new.

 

[Jims86]

i have had the fuel pressure as low as 8 lbs. it floods a little less but ran bad after it warmed up. i have checked the timing. the idle air was adjusted after it had reached operating temp. so i didnt hear the iac sucking air like when its cold. i was able to get the idle down to 500 and then when i pluged in the iac it went back up. i didnt buy the truck new.

I am wondering if the previouse owner had the IAC out, and twisted it.
What happens if you start it, and pull the electrical plug from the MAP sensor?
And, when you checked the timing, you did pull the plug over by the brake booster?
And, here is a shot in the dark, but could you try running a ground wire from the thermostat housing bold with the other grounds, directly to the ground on the battery...let me know what happens.

 

[don]

i did unplug wire when i set the timing. it has a new iac. i will try unplugging map and check grounds

 

[don]

i started it and unplugged the map sensor and nothing changed. it may have idled faster but not sure. i ran a ground wire from the comp. ground to the batt. and nothing changed.

 

[Jims86]

Hmmm. Ok. I think you have a vac gauge. can you stick it on the pcv port, and then test the manifold vac port if you have one on the back in the cylider 8 runner, and then the MAP port on the back of the TBI unit? Let me know what those readings are. Trying to corner some possibilities.

 

[don]

pcv port is 19, the back of intake is 19 and map port is 17. while it was running and flooding i unplugged the temp sensor and the iac closed and it smoothed out alot. the rpm's went up and it cleared up alot. when i plugged it back in the iac opens and starts flooding worse again. i have changed the temp sensor 3 times so i know it's not bad.

 

[Jims86]

pcv port is 19, the back of intake is 19 and map port is 17. while it was running and flooding i unplugged the temp sensor and the iac closed and it smoothed out alot. the rpm's went up and it cleared up alot. when i plugged it back in the iac opens and starts flooding worse again. i have changed the temp sensor 3 times so i know it's not bad.

Ok...Thats progress.
We now need to check the cooolant temp sensor wiring again...I personally, would snip the black coming from the sensor plug, and crimp an eyelet on big enough for the water neck bolt....that way, there is no question about its ground.
You should then pull the computer plugs, and the plug on the sensor,and check continuity between the yeller wire, and engine ground...if you get a reading or the meter screams, there is your problem. Also another continuity check between the pcm plug and the cts plug would be good as well.

 

[Jims86]

Ok...Thats progress.
We now need to check the cooolant temp sensor wiring again...I personally, would snip the black coming from the sensor plug, and crimp an eyelet on big enough for the water neck bolt....that way, there is no question about its ground.
You should then pull the computer plugs, and the plug on the sensor,and check continuity between the yeller wire, and engine ground...if you get a reading or the meter screams, there is your problem. Also another continuity check between the pcm plug and the cts plug would be good as well.

Dont do the ground wire snip and eyelet part of that...that was a different ECM i did that with.

 

[don]

i checked the wire diagram first and noticed the black wasnt a ground. i checked yellow and black wires for ground and continuity and both were good.