View Full Version : fuel pump and hot wire ?

01-23-2006, 10:33 PM
Well Im really new to the buick crowd and Iv got a STOCK 74k 86 "T" top GN and dont really want to do much more than around town stuff and am wondering about the fuel upgrades is this something I should worry with? :stir:

01-23-2006, 11:52 PM
Like your subject suggested, the fuel pumps in these cars and the wiring to them, can and will cause problems. They were only adequate when new and the 20 years between then and now didn't help. If the fuel pump doesn't deliver enough volume, your engine will lean out and you can get severe knock at higher boost levels. A Walbro 340 pump and hotwire kit are the recommended solution. Check out www.racetronix.com They have a high quality kit. If you really want to keep it stock appearing, you may be able to get by with just the pump but you will still have mid 80's GM wiring.... Good luck.

01-24-2006, 01:49 AM
Well, your self and the previous post are correct in the fuel pump issue. A new fuel pump, hotwire and adjustable regulator are a good first step. A scan tool, with or without using a lap top, then all your gauges, oil/water and vac/boost would be the next step. This will give you a baseline as to what is going on with the car so you can troubleshoot any problems and also have "tuning room" to grow with if you wish. Hot wire runs about 90, fuel pump around 140. But by the same token if you don't have a fuel pressure gauge or hood mounted gauge then you don't know where your fuel system stands, add that to the list, gauge and T 70. Don't mean to overwhelm a newbie but these cars can give you fits if you dont know what is going on, the scan tool, gauges can tell you so. Hope this helps, Joseph.

01-24-2006, 10:13 AM
Agree with previous posts. Putting in a new pump and hotwiring it can easily be done in one day provided you have a partner to help. Just follow the instructions on this site. Also agree you will wanted an adjustable regulator and gauge to slap on as well because a new pump and hotwire will most likely up your fuel pressure. Racetronix seems to have the best deal on the pump and hotwire kit.

01-24-2006, 08:50 PM
Thanks a lot Iv now installed oil pressure remote stewart warner gauge had a bad experince with the small white tubing on a mechanical in-cockpit style. Also a rail mounted fp and a water temp and A-pillar mounted boost gauge, Iv read that the stock gauge is off WAY more often than not. My boost gauge is about 3lbs different than the stocker. Is there a link to explaine the6 Ls1 MAF benifits I will be doing the fuel upgrades verry soon. Would also like to find out about the scanmaster? or other devices to moniter this engine. Iv probabily asked questions way off topic for this thread but new and curious about this car like few Iv had before. Thanks in advance. Feel free to e-mail any info to jhanson1750@msn.com. Anyone in the League City Tx area? :drive:

01-25-2006, 02:11 AM
what's the hotwire for? my friend put in double pumpers and not sure if he used a hotwire kit.

01-25-2006, 11:12 AM
The stock wiring is pretty weak, so the hotwire kit runs heavier gauge wire (with fewer connections) directly from the battery/alternator. This keeps the voltage up at the pump, and let's the pump generate more flow.

It's not uncommon to see almost 2 volts drop with the stock wiring between the FP fuse and the actual pump.

01-25-2006, 12:46 PM
Iv probabily asked questions way off topic for this thread
Yes. :winkgrin:

Please just start as many new topics in the correct areas of the forums as you need to.

01-25-2006, 12:49 PM
what's the hotwire for?
This sounds like good FAQ fodder. With a diagram included, to boot.

The stock wiring has *seven* connections from the voltage supply to the pump. As Ken said, the voltage drop can be large. The 'hot wire' improves this greatly with a single, larger, *fused* wire to the pump using the stock wire to switch on the power.

01-25-2006, 09:25 PM
Thanks so much for the info eveyone. I will be doing the hotwire kit as soon as I can get the kit in. :hail:

01-31-2006, 12:21 PM
what's the hotwire for? Because the stock wiring pretty much sucked, even when it was brand new. There are six or seven connectors in the circuit between the battery and the fuel pump, each of them a potential problem. Some of the wiring is copper, and some is aluminum,adding to the potential for problems. The stock circuit may be only supplying 8 or 9 volts to the fuel pump, which cuts a lot off the flow capacity.

02-08-2006, 11:55 PM
Well installed the hotwire kit and new Walbro 340 and adj fpr will be delivered on friday. I also installed the chip and 160 thermastat this passed weekend and :tup: HOLY BEJESES what a diffrence. want the fuel to be able to be safe with higher boost levels. Anyway thanks for all the suggestions and comments I look foward to a long enjoyable ride in this "old black car" :drool: