LB2387
Junior Member
- Joined
- Dec 13, 2014
- Posts
- 22
- Reaction score
- 1
- Location
- texas
- First Name
- matt
- Truck Year
- 1987
- Truck Model
- r10
- Engine Size
- 350
I have a 1987 R10 with 350 & 700R4. I am having a few different issues with it that I feel could all be related.
First, when I first start the truck and the engine is cold, it will bog down really bad and barely move. If I drive it at about 2000 rpm it will smooth out and accelerate, but anything under that and it just falls on its face. It will do this until it is warm, and then will usually run pretty good. No missfires and acceleration is good. It doesnt throw any codes
Second, when I start rolling from a stop with the transmission in gear, there is a nasty grinding noise coming from what sounds like the torque converter flywheel area. You can sometimes hear it when sitting still in drive. Sounds like gears or a bearing grinding. It will only do this when it is in gear(drive or reverse). If I flip it to neutral it will stop making noise. Transmission was rebuilt a little over a year ago.
Last, When driving on the highway it is difficult to maintain speed. Also the truck seems to top out around 80-85 mph and if i try to accelerate past that, the engine starts to shake REALLY violently like its about to come apart. It will stop as soon as I let off the gas.
I checked engine vacuum to make sure that the engine itself was good. Gauge read 19-20" of vacuum at idle. Needle held steady. Popped the throttle and vacuum dropped to almost zero and settled back to 20" and held steady.
I am somewhat suspect of a bad egr valve. It would not hold enough vacuum to open while the engine was running, But it will hold 20" with the engine off. So I disconnected it but it didnt make anything better or worse. So im not sure what to think of it. The valve looks clean inside as well as the intake. The valve seems maybe a little hard to push on the diaphram, but it doesnt stick.
I have recently replaced( past 2-3 months):
map sensor
IAC valve
Ignition module
plug wires
fuel filter
In the past year I replaced:
Fuel pump
coolant temp sensor
o2 sensor( upgraded to a 3 wire sensor due to headers)
Im going to test the fuel pressure in the morning when it is driving bad to see what its at. Ive gone through about 3 Delphi fuel pumps in this truck in the past couple years. The grinding noise makes me think there is a transmission/ torque converter issue that may be the root of all my problems. Any help would be greatly appreciated
First, when I first start the truck and the engine is cold, it will bog down really bad and barely move. If I drive it at about 2000 rpm it will smooth out and accelerate, but anything under that and it just falls on its face. It will do this until it is warm, and then will usually run pretty good. No missfires and acceleration is good. It doesnt throw any codes
Second, when I start rolling from a stop with the transmission in gear, there is a nasty grinding noise coming from what sounds like the torque converter flywheel area. You can sometimes hear it when sitting still in drive. Sounds like gears or a bearing grinding. It will only do this when it is in gear(drive or reverse). If I flip it to neutral it will stop making noise. Transmission was rebuilt a little over a year ago.
Last, When driving on the highway it is difficult to maintain speed. Also the truck seems to top out around 80-85 mph and if i try to accelerate past that, the engine starts to shake REALLY violently like its about to come apart. It will stop as soon as I let off the gas.
I checked engine vacuum to make sure that the engine itself was good. Gauge read 19-20" of vacuum at idle. Needle held steady. Popped the throttle and vacuum dropped to almost zero and settled back to 20" and held steady.
I am somewhat suspect of a bad egr valve. It would not hold enough vacuum to open while the engine was running, But it will hold 20" with the engine off. So I disconnected it but it didnt make anything better or worse. So im not sure what to think of it. The valve looks clean inside as well as the intake. The valve seems maybe a little hard to push on the diaphram, but it doesnt stick.
I have recently replaced( past 2-3 months):
map sensor
IAC valve
Ignition module
plug wires
fuel filter
In the past year I replaced:
Fuel pump
coolant temp sensor
o2 sensor( upgraded to a 3 wire sensor due to headers)
Im going to test the fuel pressure in the morning when it is driving bad to see what its at. Ive gone through about 3 Delphi fuel pumps in this truck in the past couple years. The grinding noise makes me think there is a transmission/ torque converter issue that may be the root of all my problems. Any help would be greatly appreciated
