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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: J.Whit3 on January 01, 2016, 06:08:07 am
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Truck is an 87 K20 with the tbi 350. Like the title says it has no power and it sputters while cruising down the road. It seems like if I stay in the throttle it runs pretty decent. I have changed all the sensors that I had codes for and no longer have a CEL light on. I installed an adapter and gauge from RVMORSEMACHINE and the fuel pressure stay at 11.5 psi while idling. Any help is greatly appreciated. Thanks in advance.
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You are on the lowest end of pressure in my opinion, I would rather see 12 or 13, but. How is the spray pattern on the injectors?
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It looks like pretty nice cone spraying out of it but this is my first tbi motor so what looks good to me might not look so good to someone else.
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IF it is coned and both are spraying you should be good.
What does the distributor look like?
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Any backfiring? You replaced sensors, but when was the last full service tune up and new fuel filter? TBI is hypersensitive to fuel pressure. A restricting fuel filter can cause all sorts of grief. And, ignition breakdown is a common cause of "sputtering."
Does driveability improve if you unplug the EGR valve - note, it will ping and may set a code?
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I just replaced the fuel filter and plugs and wires when the problem first started. The whole distributor was swapped out with another off of a running take out as was the coil. But I guess either of those could also be bad. It hasn't done any back firing yet.
Although the truck idles good I have noticed the exhaust on the passenger side has a totally different sound and if you put you hand in front of the tail pipe the exhaust feels cold compared to the driver side.
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Here's a little update. I drove the truck this morning and it did pretty decent. The truck sat here at home for about 2 hours then I tried to move it out of the yard and back into the driveway. It started up and I got it up on the road and it died. Kept turning the key over and had no fuel pressure. Finally got about 5psi and it started. When I got it in the driveway I popped the hood and looked at the gauge and only had about 9.5 psi. After this little incident I'm beginning to think maybe the fuel pump has been cutting out on me while driving down the road. I may be wrong but I always thought when a fuel pump went out it would just quit until you hit it or something. I didn't think they would go in and out like that.
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a problem that ive seen myself is in the fuel tank theres a rubber hose that connects the fuel pump to the sending unit. and the hose will crack causing the engine to run like crap and you will spend all sorts of money trying to fix the problem but you dont find it till you go to change the pump and replace the hose. some hoses arnt made to be submerged in the fuel we use now.
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Funny you say that. That happened to me already. Spent a bunch of money for nothing.