95 350 Chev won't start

aolteach · 11-04-2009, 09:34 PM

Hi all. New here. I've researching this forum for almost two hours and what great info I've learned.

I'm trying to help my computer changed Dad with his truck. Its a 95 (94 parts) Chev 350. 2WD. Long box. This truck runs on gas and propane. Factory issued propane kit.

It's a strange problem. The truck only starts around mid day everyday. Even with warm or cold days. Always around 12:00. Later that evening, won't start again. Next day the same.

He gets gas to the TBI. Just nothing to the injectors. Or the injectors are not firing.

He's getting lots of spark. Put gas in Throttle Body and it runs fine until all the gas is gone.

He's replaced.....Injectors, fuel relay, fuel pump, fuel filter, fuel regulator, ECU.

We've been leaning towards something temperature / moisture affected. Or something that controls the injectors.

Any suggestions are greatly appreciated. I feel bad for my Dad as he's getting to that discouraged stage. He's actually pretty good with vehicles.

shadygrady · 11-05-2009, 01:29 AM

Now thats odd.New injectors and all.You get fuel to the TB unit but not out of the injectors.I`d check all the engine controll fuses and make sure everything is hooked up to the TB correctly.I had a loose wire blow my engine fuse and I got crank but no start and no fuel came out of injectors.However, you say it cranks at noon only now thats really odd,maybe its ready to go to lunch.I cant see temp or moisture affecting a TBI unit as they`re used all over in all climates.Is the new ecm designed for a gas/propane truck?Are you sure its switched over to gas?How does it run on propane?

gmctrucks · 11-05-2009, 02:58 AM

Welcome to the forum and howdy from TEXAS. How many miles does the fuel pump have on it? If you ever change out the fuel pump buy a Delphi brand there much better than the other ones plus many of people have replaced theirs with a cheap brand only to remove it again after a week or sooner. Shady has some good questions.
Take care! GMC

leolkfrm · 11-05-2009, 05:30 AM

ecm temp switch in the head

aolteach · 11-05-2009, 02:53 PM

Just spoke with Pops. He's going to look closer at the ecm temp switch on head this eve.
Yes truck runs fine on either the gas or propane. Once it gets running......
Yes the ECM is designed for gas or propane. He had to give the serial number off the old one and they mathced it up. He spoke of the last 4 digits.

Thanks for the suggestions to this point.

aolteach · 11-09-2009, 11:19 AM

Changed both temp sensors. Still the same.
What a pain in the butt this has been. But we're not giving up.

1500cheyenne96 · 11-09-2009, 11:25 AM

Just a thought when he replaced the injectors did he hook the injectors up backwards on accident? had a friend do that to his truck and it wouldn't fire the injectors for some reason

chevyguy · 11-09-2009, 12:06 PM

Doesnt sound like temp to me, becasue after it starts it continues to run. When ti doesnt start i assume the motor is turning ove adn just not firing up? maybe fuel pressure to low? I would check the above mentioned fuel pump first .

aolteach · 11-10-2009, 08:43 AM

There's has been a new fuel pump installed. The symptoms are the same as with the old pump.
And appears to be good pressure up to the TBI. Just can't get the injectors to open all the time. They only open up later in the day. Very intermitent.
We have somebody much more mechanically inclined coming to visit us to day with his tools...... We're crossing our fingers.

11-04-2009, 09:34 PM	#1
aolteach Junior Member Join Date: Nov 2009 Posts: 4	95 350 Chev won't start Hi all. New here. I've researching this forum for almost two hours and what great info I've learned. I'm trying to help my computer changed Dad with his truck. Its a 95 (94 parts) Chev 350. 2WD. Long box. This truck runs on gas and propane. Factory issued propane kit. It's a strange problem. The truck only starts around mid day everyday. Even with warm or cold days. Always around 12:00. Later that evening, won't start again. Next day the same. He gets gas to the TBI. Just nothing to the injectors. Or the injectors are not firing. He's getting lots of spark. Put gas in Throttle Body and it runs fine until all the gas is gone. He's replaced.....Injectors, fuel relay, fuel pump, fuel filter, fuel regulator, ECU. We've been leaning towards something temperature / moisture affected. Or something that controls the injectors. Any suggestions are greatly appreciated. I feel bad for my Dad as he's getting to that discouraged stage. He's actually pretty good with vehicles. Last edited by aolteach; 11-04-2009 at 09:35 PM. Reason: adding info

11-05-2009, 01:29 AM	#2
shadygrady Senior Member Join Date: Feb 2007 Location: Brandon,MS Posts: 94	Now thats odd.New injectors and all.You get fuel to the TB unit but not out of the injectors.I`d check all the engine controll fuses and make sure everything is hooked up to the TB correctly.I had a loose wire blow my engine fuse and I got crank but no start and no fuel came out of injectors.However, you say it cranks at noon only now thats really odd,maybe its ready to go to lunch.I cant see temp or moisture affecting a TBI unit as they`re used all over in all climates.Is the new ecm designed for a gas/propane truck?Are you sure its switched over to gas?How does it run on propane? __________________ 1989 k1500 Cheyene 4x4,regular cab,swb,4.3 V-6.11`x 4`k&N Open element,TBI mods,smog pump delete,mechanical fan clutch to electric fan swap.flowmaster 2.5 dual exhaust.

11-05-2009, 05:30 AM	#4
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	ecm temp switch in the head __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

11-09-2009, 11:25 AM	#7
1500cheyenne96 Senior Member Join Date: Sep 2009 Location: MIchigan Posts: 197	Just a thought when he replaced the injectors did he hook the injectors up backwards on accident? had a friend do that to his truck and it wouldn't fire the injectors for some reason __________________ me+shotgun equaled fresh meat on table

11-09-2009, 12:06 PM	#8
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,370	Doesnt sound like temp to me, becasue after it starts it continues to run. When ti doesnt start i assume the motor is turning ove adn just not firing up? maybe fuel pressure to low? I would check the above mentioned fuel pump first . __________________ Friends dont let friends use body lifts USMC 92-96 USCG 98 to present

11-05-2009, 02:58 AM	#3
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 4,035	Welcome to the forum and howdy from TEXAS. How many miles does the fuel pump have on it? If you ever change out the fuel pump buy a Delphi brand there much better than the other ones plus many of people have replaced theirs with a cheap brand only to remove it again after a week or sooner. Shady has some good questions. Take care! GMC

11-05-2009, 02:53 PM	#5
aolteach Junior Member Join Date: Nov 2009 Posts: 4	Just spoke with Pops. He's going to look closer at the ecm temp switch on head this eve. Yes truck runs fine on either the gas or propane. Once it gets running...... Yes the ECM is designed for gas or propane. He had to give the serial number off the old one and they mathced it up. He spoke of the last 4 digits. Thanks for the suggestions to this point.

11-09-2009, 11:19 AM	#6
aolteach Junior Member Join Date: Nov 2009 Posts: 4	Changed both temp sensors. Still the same. What a pain in the butt this has been. But we're not giving up.

11-10-2009, 08:43 AM	#9
aolteach Junior Member Join Date: Nov 2009 Posts: 4	There's has been a new fuel pump installed. The symptoms are the same as with the old pump. And appears to be good pressure up to the TBI. Just can't get the injectors to open all the time. They only open up later in the day. Very intermitent. We have somebody much more mechanically inclined coming to visit us to day with his tools...... We're crossing our fingers.

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