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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: icket on May 07, 2019, 09:04:44 pm

Title: 1987 R10 sluggish
Post by: icket on May 07, 2019, 09:04:44 pm

I have a 1987 Chevy Silverado, completely stock.  I bought this truck a week ago and have done the following:
Spark Plugs, Distributor Cap and rotor, coil wire, fuel filter and a EGR valve. After installing the EGR it helped. It still though is sluggish doesnt feel like a 350 fuel injected motor.
The truck does not have any o2 sensors and does have true dual exhaust with an H pipe.
Im not looking to put in a cam or put on nos or turbos.
I want to optimize the motor I have and have it run like it did straight from the factory.

Any suggestions?

Thanks!!

Eric

Title: Re: 1987 R10 sluggish
Post by: Rapid Roy on May 07, 2019, 09:12:10 pm

Welcome

Title: Re: 1987 R10 sluggish
Post by: Irish_Alley on May 08, 2019, 03:10:04 pm

whats your base timing set at?
any "check engine" light?

Title: Re: 1987 R10 sluggish
Post by: MIKE S on May 08, 2019, 03:22:52 pm

If you are running a TBI system you should have a O2 sensor in the driver side manifold. If you don't its going to be in open loop all the time.

Title: Re: 1987 R10 sluggish
Post by: icket on May 08, 2019, 04:00:53 pm

I do not know what the timing is set at, although I know its supposed to be 0.
Yes I have a check engine light.

Title: Re: 1987 R10 sluggish
Post by: icket on May 08, 2019, 04:02:49 pm

I thought there was also a 02 sensor after the catalytic converter.  Since the converter is gone, there is not one beyond the converter.

Title: Re: 1987 R10 sluggish
Post by: VileZambonie on May 08, 2019, 04:20:12 pm

It's OBDI and does not monitor catalyst efficiency. It uses one primary O2 sensor located in the driver's side manifold collector to control your air fuel ratio in closed loop.

Title: Re: 1987 R10 sluggish
Post by: Irish_Alley on May 08, 2019, 06:01:40 pm

the open loop should increase his fuel and she should have a little more pep. it would be the same thing as when you first run the engine cold. but yes he should have an O2 or the check engine light should be on

Title: Re: 1987 R10 sluggish
Post by: icket on May 08, 2019, 07:00:01 pm

Thanks for the help.  I will replace and report back.

Title: Re: 1987 R10 sluggish
Post by: icket on May 13, 2019, 08:32:42 pm

Ok here is the update....I replaced the 02 sensor, EGR, cap, rotor, spark plugs, coil wire, coolant sensor (front of the intake), fuel filter, pcv valve, checked for vacuum leaks (pulling 18 inches of vacuum) and checked the timing (with max vacuum it is 3°advanced).
Still a dog!!
Check engine light is gone.

Any more ideas?

Eric

Title: Re: 1987 R10 sluggish
Post by: bd on May 13, 2019, 09:04:25 pm

What do you mean by, "with max vacuum it is 3° advanced?"  Did you bypass EST (disconnect the tan/black wire) with the engine warm before checking the timing?  Have you measured the fuel pressure?

Title: Re: 1987 R10 sluggish
Post by: icket on May 14, 2019, 07:48:21 am

Yes...with engine warm I disconnected the tan wire and hooked a vacuum gauge to the vacuum port on the TBI.
I then adjusted the distributor back and forth until I read the most amount of vacuum on the gauge.
It was then 3° advanced.

I have not checked fuel pressure.

More ideas?

Title: Re: 1987 R10 sluggish
Post by: bd on May 14, 2019, 10:17:22 am

Check the fuel pressure.