stalling problem

[Robh]

I searched for hours and hours and came up with nothing. I have an 88 comanche, automatic and the truck dies when you step on the gas when it warms up. You have to give it lots of gas like you're trying to burn out. I just bought the truck a couple weeks ago and it appears to have new cap, rotor, plug wires, and plugs. The po did replace the exhaust manifold gasket but must not have gotten it tight enough as it does have a pretty bad exhaust leak. Could the exhaust leak be causing the problem? The truck drives great down the road, no sputtering or anything and seems to idle pretty well. It is only on takeoff. Any help is much appreciated.

[mvusse]

What engine? 2.5l 4 cyl or 4.0l straight 6?

[Robh]

Sorry, 4.0

[Wildman]

Generally what your describing is........'A lack of power from a standing start'

 

First thing that comes to mind.......is the Catalytic Converter. A plugged cat will cause 'extreme' back pressure. This could also be your "exhaust leak" problem. Too much back pressure......needs to find a easier vent.

 

It could also be as simple as the exhaust down pipe is restrictive, either bend, or crushed, and for the $26 part.......might be worth "fixing"

 

it appears to have new cap, rotor, plug wires, and plugs.

 

Might be worth double checking........are they the right plugs???? Are the wires in the right firing order??? Are the plugs gapped correctly??

 

On the far scale of your problem.........are the brakes locking up?? Like a bad caliper, holding pressure after you let off on the pedal?? Is the torque converter shot, robbing engine power??

 

And last note........how fresh is the gas in the tank???? If you just got this, how long did it sit, and when was the last time you put fresh fuel in the (empty, cleaned out) tank.

 

Also, check/change the fuel filter, and if you can, do a fuel pressure check.

[BLHTAZ]

I was also thinking exhaust restriction as Wildman said.

 

The loose manifolds would cause a high idle problem from sucking in too much air if the intake manifold was leaking.

[Robh]

I am leaning towards the exhaust leak. The truck has been sitting about a year, was hit on d/s rear bed. When I bought it the truck was on empty, I am wondering if the fuel pump may be bad? I put it on the rack at work, I work at a 4wheel drive shop, this morning and the fuel filter is brand new, new 02 sensor, the plug wires are in the right firing order. The exhaust leak is horrid! Looks like quite the pita to get to the bottom manifold bolts. I did tighten the uppers, they were pretty loose. Looks like the po had the exhaust completely redone, from manifold back, new cat, muffler, down pipe, and tail pipe. I picked this truck up for $340 and it is mint, minus the bed. Factory bucket seats, floor $#!& auto, full gauge package, a/c that works, cruise that works, pwr windows and locks. Could the TPS be the issue? The thing runs great in all aspects except initial takeoff.

[BLHTAZ]

The TPS is possible.

 

I posted the testing procedure in the DIY forum HERE