HELP!! Replaced Opti and wont start!
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Joined: Mar 2012
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From: Hagerstown
HELP!! Replaced Opti and wont start! I have a 1987 Chevy truck that is lifted 10 inches with 40 inch tires that someone had swapped a LT1 out of a 1993 Corvette into. I had no knowledge of the LT motors prior to buying this truck. I am more into the old carbed motors. I took it mud bogging and the truck just suddenly cut off. I later learned that the distributor is under the water pump. So I assumed it got wet. Well I towed it home and the truck sat for 6 months before I got around to fixing it. I tore it apart and put the OptiSpark in and put it all back together and the truck was hard to start and when it did start I had to hold the gas pedal to the floor and it would barely stay running and it sounded like it was running on 4 cylinders. So I tore the motor back down and took the number one spark plug out and brought the engine to top dead center and the key lock was in the 9 o'clock postion and I reinstalled the OptiSpark and put the truck back together and it still won't start. It's getting spark and the motor will only run if I spray Starting Fluid in the intake and once the starting fluid is gone the engine dies. I put a fuel pressure gauge on it and with the motor cranking the needle jumps from between 40 and 50 pounds. When I turn the key on and just leave it on the on position the needle goes to 48 pounds and steadily drops down around 20 pounds. What does that mean? I can hear the pump kicking on when I turn the key on. I know they are supposed to have between 41 and 47 pounds, what does it mean if the pressure bleeds off with the key on the on postion. Please help cause I'm new to the fuel injection thing and I'm getting frustrated. Thank you for any information on how to solve my problem.
Try reading this:
http://www.mainstreamtopics.com/foru...rt-diagnostic/
It will give you a starting point. Just for reference the LT1 can be run without the water pump installed for a short time when doing a optispark R&R just to make sure it runs correctly before covering the opti with the WP.
http://www.mainstreamtopics.com/foru...rt-diagnostic/
It will give you a starting point. Just for reference the LT1 can be run without the water pump installed for a short time when doing a optispark R&R just to make sure it runs correctly before covering the opti with the WP.
Thread Starter
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Joined: Mar 2012
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From: Hagerstown
Yeah that's what I did this last time. I still don't have it all back together in case I have to tear it back down. Like the belt and everything is still off and ok bud I'll check that link out. Thanks for the info. I live in the country and no one around here works on stuff like this. As soon as i figure out this site I'll put pictures of the truck on here. But thanks again for the info. I'm just now getting into the fuel injection scene. My dad used to restore old cars so all I know is carbed engines. I'm not doing bad for only 20 years old!!!
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From: Hagerstown
Sandman2100 - yeah I know, that's exactly what I said after I found out that the Opti was under the water pump. I had no knowledge of the motors when I bought this truck. I believe the person who built this trucks intentions were to make it a show truck.
Foxslaughter - I would greatly appreciate it of you could remember what you did to fix it. It's driving me crazy seeing it just set in my driveway. And I thought about switching it over but these motors just run extremely well. I'm just thinking about not using it for mud bogging. I mean this truck has so much power it will break the 40" tires loose from like a 30-35mph roll. Hondas won't **** with it and when they do.......the get beat and are very disappointed lol Haha I love it.
Foxslaughter - I would greatly appreciate it of you could remember what you did to fix it. It's driving me crazy seeing it just set in my driveway. And I thought about switching it over but these motors just run extremely well. I'm just thinking about not using it for mud bogging. I mean this truck has so much power it will break the 40" tires loose from like a 30-35mph roll. Hondas won't **** with it and when they do.......the get beat and are very disappointed lol Haha I love it.
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Argh for the life of me. Mine did it at Napa. I had to have it towed home on a flat bed. Its obviously a fuel issue. Everyone though it was my fuel pump, I changed the filter. Didn't fix it. The optispark tells the injectors when to fire. I can't remember.
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TECH Fanatic
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They started TBI in 87 and very few vehicles had it.
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From: Hagerstown
Sorry for the delay on responding. The truck has a pump in the tank. When I turn the key on the "on" position you can hear a real loud low humming noise like a aftermarket fuel pump but it stops humming after 3 seconds. It's always hummed since i owned the truck but when it was running it never hummed. Everyone told me if it was aftermarket it would hum all the time even with it running but it doesnt. They said the loud hum is the fuel pump going bad. I have no clue.
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Stock fuel pumps hump for 3 seconds, its called priming. Its good practice to get in your car, turn the key on, put your seatbelt on, then start the car. This will stop a lot of hard to start problems. You let the pump prime the pressure.
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From: Hagerstown
I never wear seatbelts but I always do let the pump prime before i start it lol. But I've owned like 20-30 cars already and I've never heard a stock pump being this loud. They say its that loud cause it was about to go out. Do you think its the pump?
