High Fuel Pressure 90 PSI

Ryan Jones · October 4, 2016

Hi im having trouble with a 2000 chevy blazer . at first it had really low fuel pressure so i changed the regulator under the plenum no change. So i went ahead and got the pump changed that and now it has 90 psi at schrader valve.

It does start up and run but it has black smoke smell of raw gas coming out of tailpipe it wont idle but if you keep on gas it will run
What can be causing this bad regulator even though its brand new or the injectors?

any help would be appreciated thanks

Im thinking of putting my old fpr back on ...

Ryan Jones · October 5, 2016

ok So after i wrote this earlier i went ahead and took the plenum back off put my old regulator on there key on 62 key off 55 . after i got it back together it runs but it still goes pretty high im going to check it cold in the morning .
it did have black smoke coming out of tail pipe but after i switched it it definitely changed something i also blew the return line out when i changed regulator i took the line off pump can this pump have to much pressure for a regulator to work. or

silverlite · October 5, 2016

The best places to get help are:

Blazerforum.com

& YouTube videos

The link below covers your questions & present issues. This link covers the symptoms, diagnosis & repairs needed. After reading it thoroughly, if you still have questions there are many other posts regarding fuel issues. Also, register for the forum & other members will be happy to assist you. There are many mechanics who are members on this forum. The website is dedicated to all things related to Blazers. Please take the time to read everything thoroughly. The members are very helpful but if the question has already been clearly & thoroughly answered you probably won't get another long explanation. They usually just repost the link to direct you to where it's already been answered.

http://blazerforum.com/forum/2nd-gen-s-series-1995-2005-tech-41/how-check-regulated-fuel-pressure-pump-max-output-leakdown-88305/

YouTube is an excellent source of step by step instructions in video format. The 4.3 Vortec engine has tons of diagnosis & repair videos already posted. Also, many of these videos are on Blazers. Extremely helpful!

These 2 places will save you a ton of headaches.

I will tell you: your 2000 Blazer model uses the spider fuel assembly. It has 1 main injector & 6 individual plastic poppets to deliver fuel to the individual cylinders. Unfortunately, they stick way out & are very prone to getting carbonized & brittle causing debris to clog your fuel system. In fact it's a common issue that creates havoc on the Blazers that came with it.

Later GM switched to a spider assembly that has 6 individual injectors. These injectors are shorter, more durable & increase fuel mileage a little bit too.

Amazon & EBay sell the retrofit kits. The most popular brands are A/C Delco & Delphi. The kits run about $225 brand new.

If it's not in your budget then look in a junkyard. There are many vehicles that came with the upgraded spider assembly. Wikipedia has a list of all of the vehicles that came with this assembly straight from the factory. If there's an LKQ near you the parts are much cheaper but you have to pull the parts yourself.

Please come back & post what solved your problems. It will help others who read this in the future. Plus, I'm always curious to see what's causing the issues & what fixed it.

Thank you very much!

Ryan Jones · October 6, 2016

Well this morning i fired it up started smoking black. went for a ride about two blocks from home i stepped on the gas as i did that the engine died i rolled into someones drive way i knew the person so i looked under the blazer on the fuel pump for the high pressure the plastic fitting broke flush off and the line was sitting there with the plastic piece. so now im needing another pump lol.