engine stalls

The information is attached.

Thanks

I don't think the attachment worked so I'll type this out.
A little about me first.
Age: 71
Income: Social Security,
Medical issues.
About the pick up.
1990 chevy 3/4 ton LT. Which means Light Truck, which means two wheel drive.
Problem(s)
Truck stalls on acceleration and up hill. Even a slight grade stalls it. Pulling out from a light or stop sign gets me lots of honking from the cars behind me. Most times the engine will kill if I keep trying to go. If I pop it into neutral I can usually get it to rev up enough to continue. As things were being tested I could hold the brake, trans in gear, accelerate and get the same results as if driving. It is parked until further notice.
A well-meaning mechanic thought it was the fuel pump and put in a new one along with a filter (2 hours labor charge).
The old pump was only three years old. I didn't think it was the problem. It wasn't.
A mechanic did all kinds of tests while I did the throttle/brake thing.
The throttle cable was very loose and I found by pushing the throttle bracket back a little, I got slightly better--"performance", meaning I could get it out of the way of others.
I have tested the following by unplugging.
Oxygen sensor, temp sending unit, TPS.
I also did diagnostic with a meter on the TSP. These were the results:
Black meter lead on ground
Red meter lead on signal
(I skinned a spot on the wires rather than trust a backprobe)
Key on, throttle relaxed, meter reads 0.62
Gradually open throttle, meter reads 4.44 with no odd readings between. A smooth transition through numbers. People on line recommend changing everything with a wire attached from the battery to the fuel pump. I see several hundred dollars flying away. I can't do it.
Check engine light not working, OBD1 has a blank screen.

Any ideas on what and how to test will be very helpful.
My fingers don't work well any more so I hope a great deal of dexterity is not required.

Thanks,
Gerald

Oops. A typing error.
I meant to type " Diagnostic with a meter on the TPS."

codes.rennacs.com/Petrol-Engine/North-Am...-Powertrains.phpThis link may help you get fault codes. As per the comment on the other thread you (accidentally) started it may be the MAf sensor - if the vehicle doesn't read the correct amount of air it doesn't give the correct amount of fuel. You can get spray-cleaners for them.
Also with regard to the correction you typed - there is an 'edit' option at the bottom of the thread after you post it

A mechanic told me that the reason I had no check engine light and the OBD1 stayed blank was that the ECM was bad.
A tech guy said if the ECM was bad I would not be able to even start the engine. He said to look for a broken wire from the ECM to the OBD1 plug. I've looked and will look some more.

Check the bulb of the check engine light in the dash display - it may be as simple as that.
Some mechanics just make stuff up to sound like they know what they are talking about.

One more thing. This pick up does not have a MAF on it. It is a 1990 350 engine and I understand a MAF was not part of the factory design.

Do you have further info on it? Exact engine model etc? That could really help in diagnosing the fault.

Hi clif,

Does the engine idle hunt up and down?

or, does the idle speed in Park seem too high or too low?

Have you looked at any of the spark plugs, to see if they look white, reddish brown, grey, dark dry black, dark wet black?

Does the engine stall at idle if you lift up on the EGR diaphragm?

Based on your original post I would be considering the fuel regulator diaphragm in the TBI unit, or the functionality of the MAP sensor(make sure the vacuum hose from the TBI unit to the MAP sensor has no holes or cracks in it).

If you have to feather the throttle to keep it idling, look at the front bottom right of the TBI unit ( the side with the accelerator cable) and you'll see a small Aluminum welch plug, the kind they used on older outboard motor carbs. Drill it out, behind it is a Torx-10 screw, screw it in clockwise, about 1/4 to 3/4 turn. Your idle speed will increase. Just make sure the TPS voltage doesn't exceed 0.8 volts.

Is this a single coil system? Then I'd also check how far the spark can jump. I've seen cars with a similar fault and at about 2mm the spark looks really strong but as soon as you make the gap slightly bigger it disappears. If the coil has a crack or the main HT lead or rotor [assuming it has a distributor?] has a gap then it can only provide enough spark for idle compression - anything greater and the spark finds an easier route.