1G Walbro Overheating?

[LarryJoe]

So today I was out doing some pulls tuning my car. It was about 90 degrees out and I had a tad over 1/4 tank. Well I first started at 22psi and had a afr around 11-11.3 to redding every pull but I couldn't get rid of knock unless I took my timing down further than I wanted. As each pull went one after the other i was noticing my pump getting louder and louder. To a point where it was so incredibly loud people would look from their cars with the windows up and notice the pump whine. So I decided to compromise and turn it down to 19psi. I did a pull with good afr's and no knock until above 6k rpm when it randomly spiked into the upper 12's afr. Did it on 2 pulls before I took the car home. I let the car cool down for quite a few hours and started it and the whine was going. Did I just overheat the pump or should I look into replacing it completely? It's a Walbro 190 btw.

 

[GST with PSI]

Pull the sending unit and check the tank for sediment. If there is sediment in the tank, the sock can get clogged and cause the pump to get starved, which would cause symptoms like you're describing.

If the tank is clean, you may have a failing pump. As the pump motors go bad/fail, they can overheat and make noise. If you can check the amperage the pump is pulling, that would give you an idea if it's failing. The pump will typically pull excessive amperage when it goes bad due to the motor failing and/or being overworked.

 

[LarryJoe]

I noticed it did this on me last year as well. When I was driving to the shootout about 3 hours in the drive. Once the car sat overnight it was back to normal the next day.

 

[GST with PSI]

Again, there are a few problems that could cause your symptoms. Check the few things I mentioned above and you'll likely uncover the issue.

 

[Dsmkauai]

Is the pump rewired?

 

[LarryJoe]

Pump is not rewired and yeah I'll pull the pump today after work and check it out. Might upgrade and replace anyways for peace of mind.

 

[Dsmkauai]

Would be a good idea to do. Will help keep things more consistent especially in boost.

 

[diambo4life]

Dirty strainer = pump working harder to suck/push fuel. I would attempt inspecting condition of strainer first and replacing it. I personally do NOT like Walbro strainers. They get clogged too easy. I used to use the stock strainer on them with better results. YMMV.

 

[DJ23GSX]

I had a similar problem with one of my old Walbro pumps. Car would run great for a few pulls then all of a sudden go lean up top and knock. I would let the car sit over night and it would be fine again for a couple pulls. Every once in a while the pump would let out a weird squeal so I knew it was time to replace it. Never had another problem after I replaced it.