Poor throttle response and idle

[dscowell]

I was driving my truck and was having a lack of throttle response. I'd floor it and it would putter a long and want to speed up but couldn't. It sounded like at one point it was back firing but the sound was near the manifold not the cat. Pulled out of the way and turned my truck off. Started it back up and it had a terrible start idled at about 250rpms then shot up to 2000 then back down to 250. Didn't seem to be a timing or vacuum problem. Any ideas?

1990 Jeep Comanche 4.0L

[Jim]

Any mechanical work or change to it recently?

Backfiring through the intake - has a muffled sound - fwump

[dscowell]

No, replaced my brake booster but that shouldn't effect the engine.

[The StRanger]

Ya it will.
If you don't have a good seal at the booster your Gona have a vacuum leak..
Vacuum leak is "very" bad ju ju..

[dscowell]

Ya it will.
If you don't have a good seal at the booster your Gona have a vacuum leak..
Vacuum leak is "very" bad ju ju..

Leak at the booster! Thanks for the help guys problem is now solved!

[Jim]

one step forward!


So, um, is the vac leak sorted or is the "replaced" booster bad / bad diaphram?

[The StRanger]

Leak at the booster! Thanks for the help guys problem is now solved!

So, what was it ?

[dscowell]

The joint/connector for the hose to the booster was loose. I was able to get it closed again. I'll most likely get a new piece so this doesn't happen again. I think the hose I had on there was too short which was putting force on the piece causing it to open up slightly causing the leak.