No power when accelerating

SQUARE BODY LIFE

MEMBER
1986 CHEVROLET S-10
2.8L
V6
4WD
MANUAL
273,000 MILES

I just picked up this Blazer, 5 speed thought it was pretty rare so I jumped on it. The Blazer had been setting for awhile and needed a fuel pump so I put a fuel pump in it and drove it home no problem. Next morning went to start it up no start just crank so I sprayed starting fluid in it took a minute but started up idled good. I took it to car wash below house got the sap off it and noticed had a leak in tire tried to make it to get air and ended up riding on rim shaking around finally got a spare on it but now it would only start up with starting fluid. So I dropped the tank and noticed the gas was completely deteriorated with rust. I emptied it out and the gas looked like pure rust. Put another pump in it and changed fuel filter and it starts right up every time now, but when you put it in gear it moves maybe three feet before stalling out. The weird part is if I cut the engine off and right back on and take off in first gear it goes perfect for about two seconds then starts bucking and jerking and has no power. I had to keep repeating this process just to get it back home. I replaced fuel pump, fuel filter, map sensor, ignition coil took the plugs out and cleaned them they looked good and all were firing. I put a hole in the converter thinking maybe it was clogged but still doing same thing. I am mechanically inclined and had about 13 of these things this is my second one in manual so I would love to get it back to normal. Also, now it acts like it's starting to idle rough. Injectors look like they are spraying a good cone. Could it be the bad gas got inside the engine and clogged it up or distributor, idle air control, possibly cracked dizzy cap? I just want it to run good again and I have no idea what to replace next. Thanks in advance you guys usually nail the culprit when I ask a question.

5 Replies

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Hi and thanks for using 2CarPros.

Before replacing anything, scan to see if there are trouble codes that may direct us to the problem. This has an OBD1 set up and all you need to retrieve codes is a paper clip or jumper wire. Here is a link that shows how it's done and what the codes mean. Also, make sure the throttle body is tight and there are no engine vacuum leaks.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Let me know what you find.

Joe

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Monday, January 7th, 2019 AT 7:30 PM

SQUARE BODY LIFE

MEMBER
3 POSTS

Alrighty so I have checked engine codes that is usually first thing I do when I encounter a problem with the obd1 I jump the ports to a and b and count the flashes but unfortunately no codes. So I did a little thinking and I think I came up with the diagnosis when I first got the Blazer he said it set for about one year or so and the pump was bad I will (include photo of the pump) and when I say this thing was shot I mean it was completely melted. So when I put the new pump in it it ran like a brand new one of course that is until the contaminated rusty gas got into it and ruined it. I dropped the tank and poured the gas out it was completely orange this tank is so bad no amount of acid is going to save it in the world that would explain the ruining of fuel pumps. Of course most cars do not have engine codes for faulty fuel pumps and the sender I think is still okay since I'm not having issues with the gas hand. So all in all I know I need a new tank that's for sure my question is would the rusty gas hurt the engine like damage the push rods and would you recommend a engine flush? And if so what do you recommend? Also I will include pump and filter photo. Thanks in advance.

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Tuesday, January 8th, 2019 AT 8:39 AM

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Wow, that is a mess. I agree. As far as the engine, I really don't feel anything would have gotten into it that would cause harm. However, if the rust or dirt got past the filters, it could cause an issue with the injector. But you said you are getting a good flow.

I would suggest doing what you suggested. I feel that is the best place to start. If you can, when the pump is out, I would remove all filters and try to blow out the fuel supply lines from the engine back. Avoid blowing from the tank to the motor.
Let me know what happens.

Joe

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Tuesday, January 8th, 2019 AT 7:54 PM

SQUARE BODY LIFE

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Sorry for the late reply. I picked up a tank from the salvage yard also purchased a new fuel pump added some new spark plugs and I must say the Blazer is running so much better does not quit when coming to a stop, no bucking or jerking restored most of it's power, I can actually enjoy it now. Only small issue I have now is when taking off from a stop and I push the gas to accelerate for the first three seconds it feels kind of sluggish then clears up drives great. I will check my fuel pressure to be on the safe side also MAP sensor, idle air control valve ( i.A.C.V) but all in all it's so much better I appreciate you guys. Do you guys know the correct fuel pressure at idle? Also correct pressure when in gear?

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Friday, January 11th, 2019 AT 9:48 AM

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Welcome back:

I owned a 1986 with the 2.8L manual transmission years ago. Funny, I remember it acting the same way.

Regardless, I'm glad you got it going. Here are the directions for testing fuel pressure. It is with the engine running and at idle. They don't provide it any other way. I attached the required pressure specifications in picture one.

Also, here is a quick link that may be helpful that shows in general how to check pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

___________________________

FUEL SYSTEM PRESSURE TEST
FUEL PRESSURE TEST
- Turn engine "OFF" and perform Fuel Pressure Relief procedure.

CAUTION: A small amount of fuel may be released, after the fuel line is disconnected. In order to reduce the chance of personal injury, cover the fitting to be disconnected with a shop cloth. Place the cloth in an approved container when disconnect is completed.

- Install fuel pressure gage J-29658A/BT8205, or equivalent, at the outlet side of the in-line fuel filter.
- Start engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi).
- Relieve fuel pressure.
- Remove fuel pressure gage.
- Re-install fuel hose or pipe assembly to in-line fuel filter.
- Start engine and check for fuel leaks.

*** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 90-6C-89, Dated 9/90

Some 1985-90 engines equipped with 2.5L, 2.8L, 4.3L, 5.0L, 5.7L or 7.4L may experience a condition where fuel delivery is interrupted to the engine causing a "no start condition". This condition may be caused by deterioration of the in-tank fuel pump coupler hose located between the fuel pump sending unit and the fuel pump. This condition may be repaired by replacing the original coupler hose with a new VITON coupler hose kit P/N 25028041. The kit consist of a new VITON hose and two clamps.

_____________________________________

Let me know if this helps or if you have other questions.

Take care,
Joe

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