TBI 350 starting problems (PROBLEM SOLVED)

[ftoy516]

Just wondering if anybody here has any experience with a TBI 350 that is hard to start...I am currently at a loss.

Some of the things that I have replaced so far include;
Completely new distributor
new coil
new oil pressure sending unit
new 30A circuit breaker for IGN and BAT
new Fuel sending unit and fuel pump
cleaned ground wire connection on the block

I had this truck running before some of these items were changed, but it was hard to crank back after it warmed up, I tought that issue was the pickup coil which led to getting the new distributor and coil. and now for some reason it does not seem to be getting fire now, I can see it getting fuel. I used a meter and checked for 12v at the coil and everything seemed normal.

if anyone has any ideas I would really appreciate any input.

Thanks

 

[30th6]

Re:

Mine starts and run but is rich and has a stutter, I'm lost with these old tbi. Good luck

Sent from my SCH-I545 using Tapatalk

 

[Trailjeep]

Re: TBI 350 starting problems

Something a lot of people forget about is temp sensor it will tell it that it's cold or hot and adjust fuel for that will cause them to run rich mis or some times not start at all I would check that has fixed mine twice with this

 

[ftoy516]

Re: TBI 350 starting problems

The Temp sensor was one of the things that I did check when the truck was running before I started adding new parts....when the truck was running I unplugged the temp sensor and it started to dump fuel in to the throttle body and when it was plugged back up it would run like normal. I wonder if it is worth getting one anyway. I also just check the ground by the thermostat housing and it looks fine.

this truck was sitting for a while, however when I got it cranked it ran fine. I let it sit and idle multiple times before I decide to get the new parts to fix the hard start issue.

 

[Trailjeep]

Re: TBI 350 starting problems

Ya I would probably put one in there not that much and just hard to tell if there bad or not

 

[Elliott]

Re: TBI 350 starting problems

How did you set the timing?

 

[s10me]

Re: TBI 350 starting problems

what is your fuel pressure, do you have injector pulse, do you have good spark? what upgrades have you done that good have changed your timing curve at start up?

 

[ftoy516]

Re: TBI 350 starting problems

I set the timing at 0 degree when the #1 cylinder was at Top Dead Center on the compression stroke. The rotor was pointing at the #1 piston, and all of the plug wires were double checked and in the correct order 18436572.

I pulled all of the plugs out when I timed it, I turned it by hand before I attempted to start it with the battery.

I am really drawing a blank

 

[Elliott]

Re: TBI 350 starting problems

You need to unplug the plug on the firewall and set the timing with a light, these motors are different than a normal hei setup. I bet this is your problem

 

[natedawgxj]

Re: TBI 350 starting problems

^^^^^^x10

 

[ftoy516]

Re: TBI 350 starting problems

well I tried to crank it both ways with the (Tan wire with black strip) plugged up like normal, then with it unplugged.

but I did find out that you have to have that wire UNPLUGGED to time the motor correctly. I guess I was under the impression that I would get it cranked and let it warm up then set the timing with the Tan and Black wire unplugged. when I first started looking for that wire some of the stuff I read said it was under the glove box, but mine was under a panel on the fire wall beside the recovery tank.

 

[Elliott]

Re: TBI 350 starting problems

Yes that is it, Use a light and set it to around 4 degrees

 

[ftoy516]

Re: TBI 350 starting problems

alright I pulled the new distributor out and took it to the parts store so I could have the verify that it was good...and there tester showed the ignition control module was bad.

so I got an ICM from them that tested good in the store.

I put everything back together, retimed the motor to TDC on the #1 on the compression stroke...ect

thought everything would be fine, went to crank the truck and NOTHING!

I once again checked it for FIRE at the PLUGS by trying to ground it out to one of the bolts on the exhaust manifold and there was NO FIRE. NO FIRE

this is beyond me or something, this truck is a 92 with a Manual so if I understand correctly it should not have a crank position sensor.

 

[s10me]

Re: TBI 350 starting problems

check to see if any of the 4 wires to your injectors are cut or chafed at the top of your throttle body where your air cleaner sits. If so check for a blown ECM fuse

 

[ftoy516]

Re: TBI 350 starting problems

I just came in from checking different things.

pulled the glove box out and checked the power to the computer and both the right and left bank of wires had 12v
I checked the ground from the ICM to the computer and It had continuity
re-installed the original coil (no Change)
non of the wires on the throttle body looked chafted or anything...(I can see fuel being supplied to it which looks the way it did when it was running)

 

[muddinmetal]

Re: TBI 350 starting problems

Does it has an ESC? I am still thinking ignition control module btw

 

[ftoy516]

Re: TBI 350 starting problems

I just put a NEW ICM in it today, in a distributor that was BRAND NEW....I had the store check it and the one that was brand new was "bad" so I bought a "new" ICM and had the store check it before I walked out the door with it.

???Drawing a blank and ESC???

 

[RustyC]

Re: TBI 350 starting problems

I would check continuity of the coil to distributor plug wire. Possibly damaged terminal/ broken wire.
Put a spark plug in the coil wire it and see if the distributor is getting spark. Basically focus on the spark checking from the coil to each cyl plug.

 

[ftoy516]

Re: TBI 350 starting problems

that is a good idea. a good simple way to check it

I will have to try that.

Thanks for the help guys.

 

[ftoy516]

So after many long hours smashing my head on what could be wrong, I started Re-checking for fire yesterday when i got in from work...and there was nothing.

So i pulled the wire for the Coil to the Distributors Ignition Control Module and that is where ALL the problems came from....the pin connector that pushes on the ICM had gotten pushed half out of the back of the factory connector and not letting it get connection. I hate that this happened but maybe it may help someone in the future, and i know that I will check the CONNECTORS first from now on.

I have to say thanks to my wife for putting up with me losing my religion, and to Boulderdash for all of the help trying to come up with ideas to what the problem was.

And thanks to Hardline for all of the help as well