I have tried searching ...it cuts out ...

MRKING

New Parts for Old Trucks
I have a problem , and I wanted to know if the solution I came up with is correct before i go buying parts . Hopefully someone who knows their sht and can give me a yes or a no .

The Problem .
Truck starts up like a champ first try, idles for 3-5 seconds then dies . No codes . New ngk tr5's gapped at 28* , new wires , new 3-bar map ,silicone vacuum lines, and new distributor+cap+rotor . The timing has also been checked 3 times . My motor only idled at 15 vac before these recent upgrades and for the 3-5 seconds it runs , its right at 14-15 vac ... Then it dies ... I can do this over and over and over with same results each time . I am not to the point of being upset , but WTF . :rant: :rant:


I searched countless threads , and the conclusion I have come to is my fpr is going bad . I cant run around the truck quick enough to see if the fp is steady while running , but when I jumper the test plug , it holds pressure fine .
I read that when the fpr goes out , it will allow gas into the vacuum lines and bog down the map sensor . With that new found info , I decided to really check out the fpr . When I pulled the vac line off the fpr , I can smell gas vapors big time . I also remember that when the motor is cranking/ running , theres a strong gas smell .

In my head , I see my next move as buying a new fpr , but i wanted to see if there were other things to check before i reach into my wallet . I appreciate all the help I can get .
 

JSM

Active member
Re: I have tried searching ...it cuts out ...

Will it run if you jumper the test wire and run the FP all the time?
 

George Blake

DONATING MEMBER
Re: I have tried searching ...it cuts out ...

I bet the diaphragm in the fpr is damaged. This lets fuel get sucked straight into the engine. Way too rich. Won't run. Put a fp gauge on the rail and put 12 volts to the test connector on the firwall. Gray plug. Little thing. Looks like a connector for your defroster on a Ty. You'll hear the pump run. Watch gauge. See if it holds pressure when the 12 volts is removed. If not, that's it.
 

MRKING

New Parts for Old Trucks
Re: I have tried searching ...it cuts out ...

It wont stay running when I put 12v to the connector , only couple seconds . I forgot to add that it wont start at all when the throttle is open , not even a little bit . Im going to unplug the vac line on the other end of the fpr and see if gas comes out when I jumper the test plug .
 

George Blake

DONATING MEMBER
Re: I have tried searching ...it cuts out ...

It may not come out since the return line is below it. If you smell fuel at the fpr with the vac line off, it's fubar. You need a fuel pressure gauge to check it. Autozone has them for like $30.
 

MRKING

New Parts for Old Trucks
Re: I have tried searching ...it cuts out ...

Theres a gauge on my rail and I just double checked it for steady pressure when the test plugs powered . I have tried everything from 25-50 lbs of fuel pressure and the truck acts the same with the same strong rich smell .
 

10secTy

Sy-Ty builder and Tuner
Re: I have tried searching ...it cuts out ...

Can you get a datalog of it when it happends? Try to get the truck warm so the 02 is up to temp then get a datalog of it and send it to me at TurboV6@telusplanet.net

Nolan
 

ViciousV6

400HP/550FTLB
Re: I have tried searching ...it cuts out ...

MRKING said:
Theres a gauge on my rail and I just double checked it for steady pressure when the test plugs powered . I have tried everything from 25-50 lbs of fuel pressure and the truck acts the same with the same strong rich smell .

If the fpr is leaking i found fuel in my vac line when i pulled it off the fpr if that is ok. Are you sure the fuel pump is running after it starts. The fuel pump primes the engine then cut off until it starts but the truck will run on the intitial fuel feed. My firned had similar problem it was the fuel pump in the tank. Fuel pres would drop right off after started. Also could have a bad sensor i forget which ones run the truck til it warms up and then the o2 takes over. I think map and coolant temp sensor.

Hope this gives you some hope or a few other things to check out. Before you pull your hair out.

Ralph
Viciousv6
 

MRKING

New Parts for Old Trucks
Re: I have tried searching ...it cuts out ...

10secTy said:
Can you get a datalog of it when it happends? Try to get the truck warm so the 02 is up to temp then get a datalog of it and send it to me at TurboV6@telusplanet.net

Nolan
Besides taking my whole truck apart for the paint job , my recent mods were switching to the 59 code and 75# inj . I've ditched the stock o2 , and put my lm-1 where its at .I will make sure to let my wb warm up and do some datalogging .

I still trying to figure what fp my truck wants to be run at .
 

10secTy

Sy-Ty builder and Tuner
Re: I have tried searching ...it cuts out ...

Maybe then you can tell me already do you see it go lean or rich before it dies or is it to fast to see? How dialed in is the truck? If you check out everything and nothing else that any one has talked about looks to be the cause maybe it is the tune.

Nolan
 

MRKING

New Parts for Old Trucks
Re: I have tried searching ...it cuts out ...

10secTy said:
maybe it is the tune.

Nolan
I cant say how on point the tune is . I was told there is only 75# bin for the 59 and it is currently running on another truck with a similar tune . I cant remember if my lm-1 was rich or lean and will check it after work tommarrow . Can you email me a bin to rule out the possibilty ? I can shoot you some $$$ if you need it .Mrking01(at)msn.com is my email . I just need to get my truck running so I can get it back to the painters for touch ups .

PS . Could my ecm being wired for p+h over saturated have this negative effect ? I doubt the other truck with my bin is p+h .

And again I thank everyone for thier help , I couldnt have accomplished half of this without you guys .
 

JSM

Active member
Re: I have tried searching ...it cuts out ...

The other truck running the bin I sent you is Daron's. HIs is running decent, but I wouldn't say that makes it a great base yet since code59 is still very early in getting a lot of base cals.

Sending you a PM.
 

MRKING

New Parts for Old Trucks
Re: I have tried searching ...it cuts out ...

I wanted to follow up with my discovery . Yesterday , I borrowed a 2 bar map and a stock fpr to see if it would run .Besides a modded ecm , they were the last things I thought it could be since any tune I uploaded resulted in the same behavior . I still wasnt 100% sure they were what the problem was , and we all know , throwing new parts at the syty doesnt always make a fix .

With borrowed parts in hand , I thought to my self . What will be quicker to swap out since today I was feeling lazy ? I dont know about you guys , but I can swap a map sensor in 4 seconds . :lol: So in it went ,and started right up she did . :woot: Funny thing is after I ran the 2 bar , I decided to be certain the 3 bar was the issue since those biatches are 55 bucks . Swap back to 3 bar , and wouldnt you know , it still started up and runs . :dunno::screwy: I had already previously unplugged it and checked it , why now it decides to work is beyond me .

Now to see why my wb isnt displaying in tp rt correctly . All it says in actual afr is 10.0 .. I put a meter on the wire I ran to my ecm and it didnt show anything . Maybe the lm-1 lost the settings I uploaded to it when I first got it . I will have to search for what they are , I cant remember what they are supposed to be ...

As soon as my wb data can be datalogged too , I will email you something to look at nolan . Thanks again for everyones help .
 

MRKING

New Parts for Old Trucks
Re: I have tried searching ...it cuts out ...

I forgot to add , the original $59 bin was way to lean on my truck once I got it running . It seemed to hunt for idle and was cycling from 14.3 - 19.2 .:shocked!: This new bin makes me idle at a steady 11.2 -11.3 . :git: I dont have my tci tcu wired up complete yet , so no driving for me yet . Soon though , very soon ...
 
Re: I have tried searching ...it cuts out ...

Did you check the IAC? (think that's it)
I had similar symptoms with my GT.... you can see the longer one inthe pic is broken off.
Tsgt102.jpg
 
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