Bogging down on hills

[Joec123able]

I have an 87 r-10, had it for a couple years now been a good truck. When it comes to driving in the city and on flat roads it does pretty fine. The problem is when you get up to highway speeds on hilly roads it's horrible. It has always felt ridiculously weak on power, when you stomp the gas it's slow and weak. Some times when I stomp the gas to the floor while moving it will cut out on me and not go anywhere I have to let off the gas. Just driving against the wind at highway speeds makes the engine bog down and it feels like it's too weak to even drive against the wind. Going up hills is the worst especially where I live, I can't even drive the truck to town because the hills are too hard for it, it bogs down bad and when you stomp it it just starts cutting out. When I go up a hill I actually have to let off the gas to keep it going without cutting out, one time it has actually cut off on me going up a hill. I hate it, any ideas what could be the cause?

[Joec123able]

It's a 305, I believe a 700r4 trans. Throttle body injection (can't say I've ever heard anything good about the late 80s TBI lol)

[Mike R]

I'd start with a compression test before throwing parts at it.

[Irish_Alley]

also check your fuel pressure and replace the fuel filter

[philo_beddoe]

I also have a 305. First of all they are NOT powerful engines, stock that is. However, it should still run smooth and have enough thrust when floored to get itself up a hill. Is it dropping into "passing gear" when floored? Make sure spark plugs are not all fouled up, timing is right, and like they said...fuel filter and compression. If all fails and the engine is shot, just install this one:

http://m.chevrolet.com/performance/crate-engines/lsx-454-r.html#.Vk3yh188LCQ

[Joec123able]

Already replaced fuel filter, distributer, rotor all that stuff. Yes I am aware that it isn't powerful stock but if I could let you drive it, you would feel it has like half the power it should have and it should be plenty powerful to tackle some hills. Yes it gears down on hills but still bogs down! The only way I can get up hill reasonably is if I stomp it straight to the floor before I get to a hill and keep it floored all the way up the hill ( if it doesn't cut out on me when I stomp it that is.) if I let off the gas then it will bog down and cut out. I'll try the compression test and see about fuel pressure, is there anyway the fuel pump(electric) could be the problem?? I believe the truck does have roughly 200,000 miles on it so I guess it's possible it could just be worn out, but I think these engines are capable of more than that.

[philo_beddoe]

Does it maintain its oil? Any burning oil, any skipping or popping, stuttering.  Or is the engine smooth, but just a lack of power?

[Joec123able]

Does it maintain its oil? Any burning oil, any skipping or popping, stuttering.  Or is the engine smooth, but just a lack of power?

It seems to run okay and not burn much oil at all. I hardly have to check the oil because pretty much every time I check it it's right on full, doesn't leak any fluids at all either. It does however run very rich, out of the exhaust it has a strong gas smell. Also if you let the truck just sit and idle in park and listen to it the idle will change, it will be running fine then start idling very slow.

[bd]

Check fuel pressure (~11 PSI) and compression, as suggested.  Also check for a restricted exhaust and make sure the timing is correctly set with ESC bypass disconnected.  What gear ratio and tire size?

[philo_beddoe]

I concur with what bd stated, also...are you running stock carb..quadrabog, whoops i mean q-jet? (I have a q-jet and love it).  Could be carb issue.

[Joec123able]

I concur with what bd stated, also...are you running stock carb..quadrabog, whoops i mean q-jet? (I have a q-jet and love it).  Could be carb issue.

It's throttle body injection

[frotosride]

Che king the engine stuff is a definite if not for any other reason than just peace of mind. Also if you have a 700r-4 then check to make sure the TCC isn't locked up. The wiring I ground out and keep the torque converter locked. The easiest way to check this is simply by unplugging the TCC harness from the driver's side of the transmission. It's a square 4-pin plug the only one there. Just unplug it and take it for a ride. It will be obvious from the few extra rpms and quicker down shifting along with the engine will sound less restricted. This may not be the issue but it's a simple and easy check.