I replaced the Fuel pressure regulator on my 94 4.3 liter cpi last weekend. The truck ran great for about 4 days then friday check engine light came on and it started running rough again. I checked it out and the FPR had failed again. I bought it at autozone and they replaced it under warranty. Just wondering if anyone else has had multiple regulators go bad.

 

Autozone doesn't have the best reputation with their parts lasting so that doesnt surprise me. At least it was warrantied.

 

Nothing to do with autozone, more to do with this is the worst vehicle I have ever owned and who ever designed the spider injector should be taken outside and shot. They always fail and I always think I have other problems and it turns out to be this piece of crap injector and regulator. I suggest if your truck is running ok right now you sell the bastard before you waste more money on it like me.

 

Hmmm, a failed FPR will never trigger the engine light, and it also doesnt fail, it LEAKS... And you need to use a gauge to see and diagnose what its doing.

What is the code you are getting, we will help you properly diagnose your problems before you let some kid at autozone take a guess at it. If you are getting a DTC code, then you dont have a fuel problem.

Bert - dont tarnish this guys view of the truck cause you are having trouble with yours. Both of you need to do proper diagnosis and you will find thats its probably a small problem, but since you guys dont like taking the correct steps to fix it, it ends up costing you much more than it costs those of us that do proper diagnosis. Sorry, dont mean to be mean, but take it from those of us that know these things inside out...

 

Hi,

How did you isolate that the fuel pressure regulator was bad?

EDIT: sorry I just realized I'm in wrong forum. I have a 98. I assume the fuel pressure issues are at least similiar.

I have just gotten a blazer and am about to push it off cliff.
O2 sensor codes, getting like 10 mpg, idles horribly. (p1133 and -1153)

I did :

Engine flush
Oil change
Radiator flush
fuel filter
o2 sensors
Cap and rotor
wires and plugs
rebuilt the spider
put on new fuel pressure regulator

No Luck

Fuel pressure jumps to 75 when I turn key to on and then slowly goes down. That doesn't seem good. Then when I start it it is more like 85 ish, fairly steady. Very not good. I am wondering if I messed up rebuilding the spider. I don't see any kinks in the fuel line, and am about out of ideas.

Any ideas would be great.

Oh and I bought my FPR at Autozone after they tried to sell me an ERG and an IAC. Hmmm, I wonder how those would throw o2 codes, and that was their manager.

 

Dropwiser - The high fuel pressure makes me think that you were tinkering with that little nut on the side of your FPR... Its set from the factory, and you can adjust the pressure by turning that little T35 screw on the middle of the FPR. You can put your gauge on, pressure the system, and turn that screw to adjust the pressure you are working at... I would try doing that, Im sure you just turned that screw when installing it. Set it for 58-62psi and it should make a world of difference.

Other poster - we are still awaiting what codes you are being thrown.

Fuel system CANNOT set off a code other than lean run and rich run... When your spider fails, those would be the codes you get. Please report them to us.

 

I will tarnish the rep of this vehicle because it gives nothing but headaches to the unfortunate soles who are unlucky enough to own one. When you have to replace your CPI spider injector every year or so because they fail all the time I think is a perfectly good reason to dis on the person/persons behind a horrible design for a fuel injector. Honestly, lets put an electrical component inside the engine so it can fail all the time from heat is what the enginers must have said to themselves.

And oh I love taking the proper step to fixing what is wrong with my truck but when you have pretty much ruled out everything except for parts that had been replaced within a year you start to get a bad taste in your mouth when it winds up being the same problem over and over again. My leakdown test does lose pressure but nothing super fast and it doesn't help when you are not getting codes making it a probable fuel issue like you said. My intake plenum is comming off for probably the 30th time since I have owned this waste of space called a chevy blazer!

 

I have had no codes, engine or transmission issues with my 2000 GMC Jimmy in the almost 3 years I have owned it. Starts and drives like new.

 

142,000 miles, only 1 spider replacement (3 years ago) and other odds and ends that would break on any 18 year old car.... Sure, it's not new.... but for how old and beat it is I'm happy enough.

 

194k on my blazer 1 spider replacement and just got 19.5-20mpg on a 1k mile trip..i happen to own 2 a bravada and a blazer with cpi.....i hate douchbags that dont know what there talking about and throw there bad tudes toward someone who is looking for help stop wasting the op's time with your riffraff if you aint got something helpfull then stay the hell out....and its a well known fact autozone parts are from the bottom of the bucket...

to the op when you changed your fpr did you do the nut kit and check the harness for the injector, as osofly says a fpr will not throw a cel and the code that it threw would be a great thing to know. also when you had it open did you clean your egr valve and put in a new gasket