# 1993 Chevy truck hesitation



## Profish00

I drove to the store yesterday and the truck died just before the pump. I put 14 gallons and the truck was able to start up but seemed hesitant. I replaced the fuel filter, rotor and cap, no change. 

The hesitation only happens when I put it in gear and barely press the gas with my foot on the break, it just falls on it's face and revs back up and falls back on its face, rev back up and almost dies.

It just keeps doing this. When driving the truck it acts like it is starving for gas, ad will bog out on takeoff. I have no check engine light and no codes.

The fuel pump sounds like it is working OK, I can turn the key without starting the truck and hear the pump run then shut off. any help? Someone been thru this?


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## CoastalOutfitters

dirty o2 sensors
dirty injectors
about to lose a fuel pump

all of the above ???

if it's your orig. fuel pump and you routinely run the truck really low on fuel , your way past due..........


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## Profish00

CoastalOutfitters said:


> if it's your orig. fuel pump and you routinely run the truck really low on fuel , your way past due..........


Yup, 75k on it.


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## Argo

doubt it is the fuel pump....rarely go out on those models......

when mine did that I got a diagnostic and then I replaced the O2 sensor and injectors, there are two injectors that are very easy to replace and one O2 sensor that is also very easy to replace, it will cost you about $300 in parts and 10 minutes in labor if you do it yourself......


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## coachlaw

Gosh, remember when this problem would be fixed with a $15 carb kit? Are we sure technology is a good thing? 

My '92 Chevy was carbed if I remember correctly. I assume yours is fuel injected. Sounds like Argo has you fixed up though. - Coach


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## Profish00

It's carbed but still injected.


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## Angler 1

Fuel Pump


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## Profish00

Do I need to drop the tank for the pump, It's a K series. 

Where is the 02 sensor located?

I hate to seem dumb, but I've had this truck since 1993 and only replaced the battery.


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## Brew

I'd bet on the pump strainer. I've had to replace the pump/sending unit/strainer unit on all 3 90's chevies I've owned. It's in the tank Pro. The components are available seperately but I'd replace the whole thing so you dont end up having to drop the tank more then once.

http://www.autozone.com/R,APP171052/vehicleId,1894403/initialAction,partProductDetail/store,3504/partType,00078/shopping/partProductDetail.htm

Could also just need the injectors cleaned.


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## Roby

The symptoms you are describing are not caused by a bad fuel pump (won't run) or bad O2 sensor (code set). You do not have a carb, the injectors are mounted on a throttle plate. Since the problem you are experiencing started when you fueled up, the first thing I would do is check the quality of the fuel, check for water in the tank. If the fuel is good, check for vacuum leaks around the intake and all the hoses that attach to the intake. Check for a loose throttle body as well. You have an idle air control solenoid on the throttle body which may be carboned up and sticking, which can cause all sorts of driveabilty issues. you also have a fuel pressure regulator which could be bad and causing the symptoms you are experiencing.


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## Profish00

It died just before I filled it up. The pump sounds good. I can here it run and build pressure then shut off. 

I would hate to spend 300 dollars on the pump and not fix it. Let alone the work involved. I would also hate to buy injectors and not fix it.

It will start, run and rev up just fine, It only happens when under load.

Just cant start chunking money into it.

Glad I don't need it, argh!!


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## gulfeagle

Pull your idle air controller and clean it up and the port also. Use carb cleaner. If that doesn't help, I would have the fuel pressure checked. A vacuum leak will give you a constant high idle. Also a stuck idle air controller. The surging suggests the idle controller is sticking. Let us know .............


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## Argo

it is not the pump. and yes you can either pull the bed or drop the tank for the pump but that is not the problem......carb cleaner will not help an injector problem......what these year models have is throttle body injection, basically a really cool carburator.....the vacume leak is also a good thing for a quick check/fix kinda thing......also, the O2 sensor on my truck never threw a check engine light on me.....it just went bad and I trouble shot to that by replacing everything around it before replacing it and the injectors to finally fix the problem......I am sure a vacume leak could give you the same symptoms though......


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## Profish00

Whats the best way to clean/check fuel injectors. Im going to start again with the fuel system. Only because I hear the pump run up to pressure then shut off. In my mind that tells me the pump works and I have enough pressure to shut it off. I think somthing is dirty.


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## TheGoose

Profish:

I had several of those 90's model chevy trucks. They are great trucks due to their reliability and ease of service. That TBI (throttle body injection) was one of the best systems. Simple and straight forward. 


I had a fuel pump go out on me. In my experience, when the fuel pump goes out, that's it. It won't do nothing except turn over. No sputter, no nothing.

Sounds like one of your sensors relating to fuel injection has failed. Off the top of my head, here are the ones I remember most: MAP (manifold air pressure), TPS (Throttle positioning sensor), O2 (located directly on the exaust manifold, or shortly thereafter and really easy to change), you get the idea LOL. 

Since you're only had the truck for 14 years and only changed the battery, I wouldn't really say fixing it is "throwing away money". Sounds pretty reliable to me. Find a good mechanic/shop, get an estimate.


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## tx-fisherdude

Have you replaced the fuel filter?


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## floundergigging

I have had the fuel pump go out on my truck 3 times. The first time it would not start period. The other two times it would fall flat on its face when giving it too much throttle. I was able to make it home. All three times I had no check engine lights. It's not that big of a deal to change. Will take approx 4 hours. If you take it to a shop have them put a pressure gauge on the fuel rail and check pressure at idle and in gear with foot on the gas. If pressure drops it is the fuel pump or fuel filter. Good luck and let us know what the fix was.


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## sqwaby

Have a 93 like yours, when the fuel pump goes out it won't start at all. Had a similiar problem when my temp sender broke off. The computer defaults to cold start up mode which richens the fuel mix(look for black exhaust smoke).


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## Profish00

I have no time to work on it. Till this weekend. Who wants to help?


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## ANGEL

not me  
Im fishin this weekend 
but make sure you pump that fuel bulb til its hard ,ohh wait nevermind


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## Argo

I can help, wanna come to SA....


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## stargazer

Mine did that just before it quit. Is the gas gage acting strange? Mine would show empty...then jump to the correct reading. 


Profish00 said:


> Yup, 75k on it.


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## Profish00

I replaced the map sensor, no help. Replaced the idle air controller, no help. Replaced the fuel regulator, no help. So I droped it off ar Eagle Automotive they replaced the fuel pump $400.00 and she runs like a top!!!! I hope it will last another 14 years, it is my baby ya know.

Greenies for everyone, well I got to reload to catch a few. But I will


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## Argo

dam, I was wrong, mark this day as it is the first day that this has ever happened.....dont tell my wife. AND dont tell me I told you so....


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## Profish00

Thats ok Argo your truck is still better


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## Brew

$400 ain't too bad considering the parts alone would have ran ya about $250 and dropping the tank out on your back in the driveway is a couple hours work. Glad it worked out for ya Pro.

Argo, I thought I was wrong once too, but it turns out I was wrong!! 

Jeff


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## Angler 1

Glad you got it fixed.....two words "FUEL PUMP"



Angler 1 said:


> Fuel Pump


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## floundergigging

Thanks for posting the fix It helps us all. Green for posting the fix


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