Older Gm obd1 codes

[5155]

This thing has been running like crap.
Yesterday I made the check engine light blink.
Sure enough code 22 was hiding in there .
Went and bought the tps and installed.
It might have helped.
Today the check engine light is on for first time.
I jumpered it and code 21 and 22.
Both related to throttle position sensor.

Also while counting blinks the oil pressure gauge spiked one time, odd.
It's a throttle bodied 350.

Could one of you experienced fixers advise?
Maybe because I did not clear it?? dah

 

[stihl livin]

@redline4

 

[redline4]

What year and model vehicle?

I'd likely disregard the oil guage spike.

 

[USMC615]

What year and model vehicle?

I'd likely disregard the oil guage spike.

Do all TPS's have a pretty narrow mV range where they're initially set? Had one give me a code over and over on a 2.8L V6 with a 700-TBI on an '86 S-10 many, many yrs ago. Had to set it with a digital voltmeter vice analog. Just taking a stab at this possibly being the problem...

 

[redline4]

Throttle position sensor is a 5 volt sensor.
3 wire. 1 is reference voltage, 1 ground, 1 signal.
Most of them are non adjustable.
I think most were .4-.5 volts at idle on the scan tool.

 

[5155]

91 GMC k1500 350ci
150k + miles
NOT a trash wagon lol

Thing has been peeing me off,
I may have to hire someone.

The V range on this is suposed to be below .5 to 5, but don't quote me. And I have no clue how to calibrate it.

Where's my HEI and quadrajet lol

 

[redline4]

Can't get my printer to print, so had to take pic off my laptop..




Hopefully this helps

 

[5155]

Great thanks

 

[FergusonTO35]

I remember some of those V6 and V8 tbi mills were bad about one injector getting weak and running like poo with no codes or anything. Some of them would also wig out from a bad coolant temp sender. If you intend to keep the vehicle, do yourself a favor and get a scan tool that will work with it. Today's cheap scan tools will do alot more than a dealership tool did 20 years ago. Reading data line by line is a huge step forward from counting blinking lights.

 

[5155]

Got it running a lot better but code 21 still on.
Refound a young guy I can trust. In the past I could bribe him with miss-fit OPE.
He has a boss now though.
He's getting on it today, hopefully he can teach me something.
Wouldn't surprise me one bit if the problem is mechanical rather than blinky.
Check engine = distraction.
And I'm easily distracted.

I took quick look at scanners online, from 25 to 350 bucks.

Edit, young guy to my son said, "Is HE still running that truck?" lol.

 

[stretch5881]

The TPS is one of those sensors, that start a chain of events, which cause other sensors and motors to go into a tizzy. I used to stare at charts and test with a multimeter. I would start to think my vom was a pos. The TPS is made like a radio rheostat. It wears out and gives screwy values. The pcm tries to compensate. In short, replace the TPS.

 

[5155]

" In short, replace the TPS."

Been there done that.

Thanks everyone, I'll report back

 

[5155]

Prognosis from shop.

All cyls at 140 psi except one at 125
1/2" slack in timing chain measured at dis rotor
leak at cyl head to manifold gasket
changed fuel filter due to slight low press

 

[redline4]

Prognosis from shop.

All cyls at 140 psi except one at 125
1/2" slack in timing chain measured at dis rotor
leak at cyl head to manifold gasket
changed fuel filter due to slight low press

Did they pull the distributor?
The gears on those would "apple core" and wear in the middle, giving the illusion of a loose chain.

 

[5155]

I get what you are saying.
If that were the case,
Would I be able to move the dist shaft from the top side? Yes, no?

The lower psi on #1 has my more concern.

Feeling crappie about it and,
my trucks feewings are hurt but will get over that real quick.

 

[redline4]

Normally when the gear wears, yes, you can grab the rotor and get it to move some.
It could still have a loose-n-floppin chain, but its something worth looking at if you plan to keep it running.