Ianmac

Oilcanhenry
I much prefer workin on my 63 C10 fully stock the only modern things on it are a CD player and a USB Jack. Pure simplicity the only things i would like to change is disc brakes and power steering i even like the rust it has earned it.
The same can be said about my 73 Triumph Spitfire all original (no rust on this one though) except Cd/USB.
I only use 1 gas station for all fill ups exept out of town its a shell and the 63 C10 and Spitfire both only get ethanol free gas and drained each winter when i put them into hibernation.

I have never used seafoam before but have seen YouTube videos might give it a try after winter on the Spitfire and C10 and this C1500 Silverado none of them do big miles and the C1500 dont get out on the highway much i mainly use it for hauling tools and stuff for work round town and more MPG is always good.

I got my wife to listen at the fuel tank and she heard the fuel pump activate (no guarantee that it is actually working at the correct pressure but it works).

On advice I shined a flashlight into the throttle body and watched the injectors they didn't spray just dripped that indicates low fuel pressure or the TPS sensor is not good i have ordered a fuel pressure tester and will run a pressure test as soon as I can. That will tell me a lot more I do suspect the fuel pump (not looking forward to pulling the tank to change it out though) if the pressure is good I will change out the TPS sensor and like you I feel suspicious of the EGR valve so will probably swap that out too I dont think it would hurt (only my wallet) I am going to swap out the fuel filter as well it wouldbe dumb not to.

Ianmac

I looked in Autozone (my neighbor works there) I got the same fuel pressure tester from Amazon for $10 (including his discount) less it will be here Thursday.
I use a local hardware store "Dennis company" they stock lots of handy stuff like hose/pipe/tube and sell by the foot and i always buy a foot or so more than i need but best of all they stock a huge selection of fasteners that standard and metric no UNF or Whitworth my Spitfire has the odd part that needs these i have to get them from the UK that can get a bit spendy so i buy as much as i can and parts too when i visit my family in the UK i did bring all my British Spanners and sockets with me when i moved here. My wife is very patient with me while i search breakers yards while we are there i do find it hard to pass them incase i find something good like SU carburetors and MG Triumph European spec manifolds very hard to find in the USA and now getting hard to find in Europe.

Sabino56

Fact that injectors are dripping + this code which I understand as PCM saying “voltages on circuits aren’t what I’m expecting and I’m turning off chips to prevent burning out stuff” says to me that fuel pump is probably toast or short somewhere to pump is drawing too much current.

I went down the rabbit hole of chasing a quad-driver module code when I had drivability problems believing I had some problem in circuit driving injectors and it turned out to be just that bad fuel pump. Bad/marginal fuel pressure can result in all sorts of codes as PCM is assuming the right amount of fuel is being delivered for the conditions and if engine doesn’t respond as expected PCM gets confused.

check the fuel pressure / replace fuel pump, check timing (another thing which PCM can only assume is correct) then reset and go from there. Good luck!

I’m also a points & carb guy (68 Camaro)- so easy to get to run though admittedly hard to get running optimally without a lot of tuning. & performance can’t match a fuel injected/electronic ignition modern engine.
Kind of an ignorance is bliss / simpler time sort of driving....

Ianmac

Ok I got my fuel pressure tester has to buy a adapter for my system ran a test got 6psi before the filter. Bought new pump and sender unit ( old one the gauge was off full went off the gauge and from half it dropped rapidly) installed got 14psi gauge is not reading but will sort that later I suspect it is just a bad contact. Starting up is great and no service light on the dash anymore the engine runs fine exept under load and occasionally the engine sort of stutters and sometimes feels like its missing and running on 7 with a loss of power this is not consistent but occasionally. I am thinking of replacing the ignition control module and perhaps the throttle position sensor also plugs and leads as I dont really know how long thay have been there i am gonna pull the plugs at the weekend and check them out i do have a tester for the coil/ leads/ plugs ( I have to find it first) I have not ran a code test as yet as i only got it running yesterday and today was the first time i really driven it.
My real question is how do I check the ignition control module and throttle position sensor can it be tested with a AVO meter or is it just swap it out and see what happens. I still intend to put new plugs and leads in i have ordered some they will be here next week.

Sabino56

Nice it’s running better and you’re making progress.
You didn’t overtly say, did you replace the fuel filter when you replaced the pump? If not, I’d replace the fuel filter before trying to replace other things.

if you replaced fuel filter - and if you can capture data during the studder under load, I’d look to see if that’s correlated with knock counts going up.
if you can’t capture data and going to just trying replacing stuff - I’d do the plugs, wires if they are old/original first. Then I’d replace knock sensor as it’s relatively cheap and easy to do. I had some problems with a studder once on my 93 and knock sensor was culprit. When I removed it no water came from hole, it was gunked up. I’ve read (but don’t know facts) that knock sensor has to be in water jacket to work well.

you can check tps with voltmeter , I forget the resistances but should be easy to google or maybe something in here https://www.gmt400.com/threads/88-95...manuals.43575/

I've no experience checking ignition but I understand you can have module tested.

Ianmac

Yes i replaced the fuel filter that was the very first thing I done.
The plug wires look pretty old and i have never pulled the plugs have had the truck 18 months I will be doing that this weekend but dont think a new set will hurt and the cost is not to great.
I had not thought of the knock sensor will check out about the knock sensor testing later today.
Thanks for the info

oilcanhenry

Them plugs might be really hard to get off after so much time. I always use Neverseize on the threads when installing new plugs and dielectric grease to keep water out of the wires and distributor as well as lots of the other electrical plugs and light sockets. No water=no corrosion.

Ianmac

So true i use a copper based anti seize product called copperslip had the can for years.
I also use dialectic grease especially on outside electric connections i spent a lot of time as a merchant seaman unprotected electric connections dont last long in that environment

Ray Crouse

it is your throttle position sensor. You have to calibrate it with a multi meter. There Is a 5 V constant, a signal wire, and your ground. Find your 5 volt constant, Then you know the other 2 wires are your ground and signal. Splice into the signal wire without cutting through it and check that you have voltage when the key is forward with the engine off. It has to read around 0.48v Closed throttle ... Once you get it close to 0.5 v closed, use your hand and open the throttle...the multi meter should read close to 5.0 volts wide open throttle. You adjust the voltage by loosening the screws that hold it to the tbi while checking the voltage with a multi meter. Once you are in range, screw it down tight being careful not to move it or you will change the calibration again. Even a cheap $5 multi meter from Harbor freight will get you back on the road again. I suggest checking the calibration on your throttle position sensor before just replacing it.. I spent a bunch of money buying a new one and after I learned how to calibrate it, I realize I didn't need a new TPS at all

Ianmac

I just got done doing the plugs and leads loads distributer and rotor arm all where in pretty bad shape distributer and rotor where pretty worn out. The leads looked ok 1 had a tear in the rubber near the cap otherwise not to bad plugs where pretty much shot gap way off the electrode worn on all a little carbon deposit going to give it a run out shortly after I have a cup of coffee. Getting those plugs out was no fun at all especially the rear right and around the steering shaft.
Thanks for the tip on recalibrating the Throttle Position Sensor that was going to be my next target. I will try what you said probably tomorrow morning. I am going to see how it runs now it definitely sounds better and smoother. As I had said earlier I dont really know a lot about throttle body injection especially the electric side of things. Now I just think of it as a electronic controlled carburetor and learning new stuff every time.