Kaydon

Well so I replaced my injectors not long ago and ever since I've had the following issues.

Once cranked and running at idle in neutral the engine would "drop off" and then return to normal idle and it would do that consistently.

Once I pressed the brake it would chug and then die. If I cranked with my foot on the brake it wouldn't stay running for more than a few moments, I've been having to crank in neutral with the parking brake to get it to stay running.

The engine shakes every time it does that "Drop off"

I've been thinking it's the following: my brake booster is bad, a vacuum leak or the TPS is out of adjustment. Or a combination of the 3.

I haven't got a clue where to start, and so it would seem I have to buy a voltmeter.

thook

Try pinching off the brake booster line, with some vice grips, to the manifold and see what happens.

abecedarian

what is the year of the chassis in question?

Kaydon

Can't believe I forgot to include that info.. Exhaustion.

Anyway.

1992 Pickup, 2wd.. 22re.

Kaydon

Well I fixed my consistent surge issue, a hole in my intake tube.

It's not the TPS.

It does it when I mash the brakes when the truck is cold, once it warms up it quits.. Wtf?

Son of a bitch I fixed it.

It's embarrassing as to what it was...

low coolant.

LOL

thook

Embarrasing? Try putting the headbolts on and not putting the spacers on first!!

abecedarian

It's only embarrasing when other people see what you did wrong. Otherwise it's just frustrating.

thook

My best guess is that with the hole in the intake you, of course, have unmetered air = a vacuum loss. When the motor is cold, the cold idle air valve is allowing more unmetered air in that when hot. So, with the hole, you already have the vacuum loss, but even more so when cold given what i"ve said. When you mash on the brakes, which require vacuum and therefore places a vacuum load on the engine, it's more vacuum than the engine can sustain under the conditions.

I may be wrong, but it sounds good....if it made any sense.

Kaydon

It's doing it again.. Either my idle air valve is bad or there's a leak somewhere.

thook

That's just it. I had buddy there working with me. And, I was brave (or stupid?) enough to share the experience with greater YT.

Sorry Kaydon. I don't know what to tell you right now. I'd have to think about it.

abecedarian

well... been looking around and in my drunken stupor came across a mailing list which our patron saint 4Crawler was involved in and one of the posts was regarding an issue such as this.
In 2wd, when applying the brakes and the engine speed was too high, the ECU would cut the injectors to assist with engine braking. When the engine speed was sufficiently low, the injectors would be turned back on.
Now you could interpret this to have an effect like mentioned.

So I'll go about my searching and try to find the 411 I've referred to.