Hi everyone, i have a strange little issue with my 87 lg4 4bbl 700r4. in the last couple of weeks ive noticed 2 things

1st - accellerating normally as the car changes into the next gear i get a massive rev drop and a blub blub blub sort of performance. If i use the pedal a bit harder, its hidden a little more but its definitely still there.

2nd - if im on the freeway and plant my foot, the secondaries kick in and you get the nice secondary noise and a boost of power- then it feels as though they close (almost feels like going up a gear even though it isnt) and that power disappears.

These things both started happening at the same time and have so far not found any vacuum leaks or anything, ive just done the timing etc, plugs and leads only have about 2k on them. In tank pump & mechanical block pump are new.

does this sound like it could be a Air Valve Door tensions issue? or is it ringing any bells for anyone else?

 

it could possibly need an adjustment of the secondary? cant hurt to try it. but first, does it have a good clean fuel filter on it? what about the one right at the carb? sometimes they plug up easy.

 

dont they only have the 1 up near the carb? i didnt think there was another one?

 

i'm pretty sure 1987 has a filter on the drivers side, in front of the rear axle. close to the size of a beer can. cant miss it.

 

'87 also has an in-tank electric pump. The 2nd symptom sounds like running out of fuel in the carb fuel bowl (fuel supply isn't keeping up), but not so much the 1st (but may be, since you are talking about accelerating).

Since the '87 carb'd V8s had both an engine-mounted mechanical fuel pump and the in-tank electric, either or both could be the problem.

 

So turns out my 87 gets even wierder, It has 2 pumps instead of 2 filters has only the one in the carb (i threw an inline in there just for good measure) but the problem still exists.

i did have a strange issue that hasnt reoccured yet but i was driving to work and floored it - suddenly the car was dying and stumbling to the point where i had to feather the throttle to keep it going, when i parked it, it refused to start.

i popped the bonnet and noticed pools of fuel building on the intake manifold coming out of the carb. something tells me i might have a float issue... i feel a rebuild could be on the cards.

any thoughts?

 

also - the car started again when i returned to it after work and hasnt disgraced itself again as of yet...