DIY fuel pressure regulator on Blazer 4.3L CPI engine - DISCUSSION

Printable Version

Blazer >> Mechanical & Maintenance >> Do-It-Yourself >> DIY Submissions/Discussions >> DIY fuel pressure regulator on Blazer 4.3L CPI engine - DISCUSSION

Page: [1] 2   next >   >>

Login Message << Older Topic   Newer Topic >>

DIY fuel pressure regulator on Blazer 4.3L CPI engine -... - 2/20/2007 8:59:02 PM    swartlkk Posts: 14472 Joined: 5/1/2005 From: Waterloo, NY Status: offline I just moved a very good DIY thread into the DIY section. DIY fuel pressure regulator on Blazer 4.3L CPI engine The purpose of this thread is to discuss this submission.  If anyone sees anything that needs correction, please post about it here. Thanks kerander for your submission! _____________________________ Kyle- 2004 Rainier 1970 Chevelle - Resto 1974 K5 Blazer - Resto Post #: 1

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/20/2007 11:27:40 PM    Blasir   Posts: 111 Status: offline Yep, that's exactly what a normal good working 94-97 plenum looks like inside. That's what mine looked like 160K miles ago and I didn't touch my FPR or spider or nut kit because I could not see or smell any fuel leaking. "After changing mine, the truck runs smooth again, got its power back, and vastly improved fuel economy (went from 2 to 20 mpg ). " kerander (new member) You were only able to go 36 miles on a tank of gasoline? < Message edited by Blasir -- 2/20/2007 11:49:53 PM > (in reply to swartlkk) Post #: 2

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 7:29:31 AM    swartlkk Posts: 14472 Joined: 5/1/2005 From: Waterloo, NY Status: offline That is NOT what a normal intake will look like.  That cleaned off aluminum is from the fuel leaking from the FPR.  If it did not have the fuel leak, the passenger side would have the copperish color all over it. _____________________________ Kyle- 2004 Rainier 1970 Chevelle - Resto 1974 K5 Blazer - Resto (in reply to Blasir) Post #: 3

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 10:16:58 AM    Blasir   Posts: 111 Status: offline When I was told that my FPR/spider injector assembly was gone about 160K miles ago. I opened the plenum and it looked just like KERANDER's did when he opened his. I smelled no more gas than what I would expect. There were NO puddles of fuel and the FPR was copper colored and dry. Passenger side of plenum was very clean and drivers side all carbon. I did NOT change anything. It still runs super. I just think you need to be absolutely sure that you are changing the correct parts because these parts are costly and if you break the mounting holes for the FPR, you are buying a $350 spider injector. There is a member asking now for a used one because he did just that. I am posting pictures of what an ACTUAL LEAKING FPR looks like when you pull the plenum off. Notice that the leaking fuel causes the FPR to get a carbon coated burn on it. Notice that the fuel is actually all over the passenger side of the plenum. Notice that after it is cleaned, the copper color is NOT washed off the plenum. Notice that the FPR is actually wet from the gasoline. Photos courtesy of member 93LT from previous post in 2006 http://www.blazerforum.com/m_7118/tm.htm < Message edited by Blasir -- 2/21/2007 10:22:54 AM > (in reply to swartlkk) Post #: 4

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 10:47:56 AM    swartlkk Posts: 14472 Joined: 5/1/2005 From: Waterloo, NY Status: offline It all depends on how long the leak was present as to how much the plenum will be cleaned.  Now, look at the pictures in the DIY post.  Looks like there is gas pooled on the plenum, but it is very hard to tell with the pictures how they are. As always, it must be verified that there is an internal leak in the plenum either visually by pressurizing the system or with a fuel pressure guage, but to blindly dismiss the potential for a leak with a WELL documented, leak prone, spyder assembly such as is used in the CPI by simply looking at pictures is ridiculous.  *EDIT* - Never once have I just blindly recommended that the CPI unit be replaced.  I have always recommended having the fuel pressure leak down test performed and/or removing the upper plenum and actually visually inspecting the lines and other components of the fuel system internal to the intake.  A small leak may be present, but have no impact on driveability.  Doesn't mean it is OK.  Just as sticking poppet valves may not be easily diagnosed, but without proper maintenance, the poppet valves will start to stick.   I suspect with your truck because of the sheer number of miles you accumulate in a week, the poppet nozzles don't get a chance to varnish. But just because something has gone for 340k miles on your truck doesn't mean that your voice is any louder than the thousands (understated) that have had their FPR leak at under 100k miles.  This problem is a wide spread problem.  Some make it longer than others, but it is a problem none the less.  But being as wide spread as it is, many driveability concerns may be inappropriately linked to a bad CPI unit.  That is why I stress the proper diagnostic procedures be completed.  If you must use a mechanic, always get a second opinion unless it is someone you trust. < Message edited by swartlkk -- 2/21/2007 11:11:59 AM > _____________________________ Kyle- 2004 Rainier 1970 Chevelle - Resto 1974 K5 Blazer - Resto (in reply to Blasir) Post #: 5

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 12:03:31 PM    hillbillyinOhio Posts: 2884 Status: offline does this same thing happen on later versions of the 4.3?  Im getting horrible gas mileage on my 97, and i was wondering about some causes for this.  Im cleaning the EGR and MAF sensor today. _____________________________ MECP Master Installer 2007 Chevy Silverado Ext cab system to be determined 155.6 Best on the TermLab (in reply to swartlkk) Post #: 6

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 12:34:38 PM    swartlkk Posts: 14472 Joined: 5/1/2005 From: Waterloo, NY Status: offline The poppet nozzles are of the very same design on the CSFI spiders as on the CPI.  I'd run some fuel injector cleaner through the next few tanks of fuel. It is quite possible that you don't have a problem with the injection at all and that it is the O2 sensors causing a problem, but that is a discussion for a different topic. _____________________________ Kyle- 2004 Rainier 1970 Chevelle - Resto 1974 K5 Blazer - Resto (in reply to hillbillyinOhio) Post #: 7

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 8:50:32 PM    Kordog Posts: 403 Joined: 10/22/2006 Status: offline The carbon build up on the FPR is not from it leaking, it is from the normal by-products of combustion, hence the rest of the intake being covered in carbon.  When the fuel leaks out it cleans the the carbon off, just like it does it the picture above.  Every one I have replaced looked brand new, not all carboned up.  This is of course the customer always waits until they are fed up with poor fuel economy, and the hard starts.  I have replaced a ton of the FPR, and the nut kits, but only one spider assy..  And that was only due to the main injector being dead.  Korey _____________________________ Korey 2000 Blazer LT, 30X9.5x15 Dueler AT, Cold air intake, Magnaflow exhaust. ASE Master Auto Tech. (in reply to swartlkk) Post #: 8

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 8:55:28 PM    Blasir   Posts: 111 Status: offline swartlkk If you look at the picture in the DIY post where he is showing the FPR through the hole in the top of the plenum, it is actually dryer around the FPR than on the drivers side. How do you look at that and think that the FPR is bad (leaking)? I absolutely agree that thousands and thousands of spider injectors have been replaced on the 94-87 Blazers under 100K miles. If the FPR is so fragile on these Blazers, how come it is a special order part at Auto Zone, Advanced Auto and NAPA? Not even stocked at their warehouses, a special 2 week notice , pay in advance, buy it with no return part. I don't even think that mine is anything special. This is what seemed to be wrong with mine. This wire was broken. $95.00 at Chevy dealer for connector and 1 foot harness. Yikes. < Message edited by Blasir -- 2/21/2007 9:19:13 PM > (in reply to swartlkk) Post #: 9

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 9:32:15 PM    Kordog Posts: 403 Joined: 10/22/2006 Status: offline Blasir, the intake being so clean like that in the DIY picture is what tells you the FPR is leaking.  My NAPA, Autozone, and Auto-Value stocks the FPR.  I replace these all the time.  If one side of the intake is clean there is a leak on that side.  The reason it looks drier is because by the time you look at it the fuel has dried on/ around it.  And around the 2 intake bolts on the left side of the picture, if it was not so bright, you probably would see fuel sitting there.  Your picture looks as though someone cleaned it, or you run some sort of cleaner through your fuel system an a regular basis.  Every one of these motors I have had apart look like the pictures in the DIY section.  Either the whole intake looked like the right side, or the side that has the leak was clean like the left side.  Korey. _____________________________ Korey 2000 Blazer LT, 30X9.5x15 Dueler AT, Cold air intake, Magnaflow exhaust. ASE Master Auto Tech. (in reply to Blasir) Post #: 10

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 10:57:38 PM    Blasir   Posts: 111 Status: offline Whatever Korey. None of the pictures are of my truck if the thread is read properly. Enough already. (in reply to Kordog) Post #: 11

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/21/2007 11:20:11 PM    Kordog Posts: 403 Joined: 10/22/2006 Status: offline quote: ORIGINAL: Blasir Whatever Korey. None of the pictures are of my truck if the thread is read properly. Enough already. The post with the picture of the inside of the intake with the yellow arrow, and your comment under it is what made me think it was your picture.  And what do you mean enough already?  I am here helping people with the knowledge I have gained in my years of knowledge as a Certified Auto Technician.  I am not here to put anyone down.  I am just passing info along to the viewers of this wonderful site.  And since I just replaced a FPR on Tuesday, I know how easy they are to obtain now.  Korey _____________________________ Korey 2000 Blazer LT, 30X9.5x15 Dueler AT, Cold air intake, Magnaflow exhaust. ASE Master Auto Tech. (in reply to Blasir) Post #: 12

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/22/2007 7:55:35 PM    kerander   Posts: 117 Joined: 1/14/2007 Status: offline Yeah, I actually just ran the car highway only last night and it got 22 mpg with a "performance" muffler on it. Oh yeah! >You were only able to go 36 miles on a tank of gasoline?  Unfortunately, yes. It ain't fun watching the gauge go down . Yeah, these pics were taken after I had the top off and it was cold as hell outside (-10' F), i.e. so it was very dry. There was considerable gas pooling as well - as mentioned above. I mopped up some of it prior to taking the pictures cause it stank, but there was still some left. I had to wait awhile with the garage doors open cause there was so much fumes it was seeping into the house and causing my granddad to get all weezy when the doors were shut. < Message edited by kerander -- 2/22/2007 8:30:55 PM > _____________________________ 95 Blazer T-10 4.3L CPI "W" 4x4 4D 120K LT (in reply to Kordog) Post #: 13

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/24/2007 10:20:45 PM    Blazin96   Posts: 14 Joined: 10/12/2006 Status: offline I just got done doing the spider injectors on my truck because it was runnign like garbage, but only codes was p0300 so i started stupid, plugs, wires, rotors, cap, ignition control module, and coil. all replaced, lower intake was doe 5k ago so i know its not that, replaced the spider as last resort, and it still runs like garbage, i seen somone talking about the camshaft position sensor? any suggestions, i'm done replacing parts, i just want it to run good again. plz help. (in reply to kerander) Post #: 14

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/24/2007 10:40:07 PM    Kordog Posts: 403 Joined: 10/22/2006 Status: offline Blazin, I am going to assume that you have a '96, but to make sure please post vehicle info.  I would run a compression test though.  I will wait until you post more info to further help.  Korey. _____________________________ Korey 2000 Blazer LT, 30X9.5x15 Dueler AT, Cold air intake, Magnaflow exhaust. ASE Master Auto Tech. (in reply to Blazin96) Post #: 15

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/25/2007 10:28:00 AM    swartlkk Posts: 14472 Joined: 5/1/2005 From: Waterloo, NY Status: offline Blazin96, please post a new thread on your problem.  "runs like crap" isn't a good description either and we deffinitely need more information about your truck.  Please address all of this in a new post and we'll see how we can help. _____________________________ Kyle- 2004 Rainier 1970 Chevelle - Resto 1974 K5 Blazer - Resto (in reply to Kordog) Post #: 16

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/25/2007 1:00:12 PM    MNHawk Posts: 451 Joined: 10/20/2006 Status: offline Is there an on board FPR you can put in so that you can always have a reading of the FPR? Kind of like what they have on carb setups. I have tried looking over the Performance parts for race apps. but have not found anything that looks safe enough to install as a perm. gage w/ out effecting the fuel system as a daily driver. Thanks _____________________________ 74 W200 4x4 360/727/NP205 D44/D60 1981 C-20 Suburban Full Size 4x4 350 4sp manual (newest toy) 91 Honda Accord (daily Driver) 1979 Ford LGT 125 2005 JD L130 95 Blazer 4 door 4x4 4.3 lt vin W(parked selling or parting out) 93 S10 Blazer 4dr 4. (in reply to swartlkk) Post #: 17

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 2/25/2007 3:19:11 PM    Kordog Posts: 403 Joined: 10/22/2006 Status: offline Yes there are kits, usually though for this kind of pressure there will be an electric pressure sensor, then there will be no fuel lines going into the cabin.  If you goto www.autometer.com and do a search for fuel pressure you will find a few of them that will work.  The only thing you will need to do is find an adaptor that will go over your test port.  Korey _____________________________ Korey 2000 Blazer LT, 30X9.5x15 Dueler AT, Cold air intake, Magnaflow exhaust. ASE Master Auto Tech. (in reply to MNHawk) Post #: 18

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 3/12/2007 2:41:07 PM    MNHawk Posts: 451 Joined: 10/20/2006 Status: offline Here is an image with the coper color that "swartlkk" was talking about:   with injector without I do have a question though, on the spyder assembly are there suppose to be o-rings on them? Just wondering due to they seem loose in there. From the looks of it someone has had this torn down before. Just did a really crapy job of it. < Message edited by MNHawk -- 3/12/2007 2:43:02 PM > _____________________________ 74 W200 4x4 360/727/NP205 D44/D60 1981 C-20 Suburban Full Size 4x4 350 4sp manual (newest toy) 91 Honda Accord (daily Driver) 1979 Ford LGT 125 2005 JD L130 95 Blazer 4 door 4x4 4.3 lt vin W(parked selling or parting out) 93 S10 Blazer 4dr 4. (in reply to Kordog) Post #: 19

RE: DIY fuel pressure regulator on Blazer 4.3L CPI engi... - 3/12/2007 3:34:46 PM    swartlkk Posts: 14472 Joined: 5/1/2005 From: Waterloo, NY Status: offline Where the poppet nozzles go down into the lower intake manifold...?  No, there are not supposed to be o-rings there.  Those holes are just as sloppy on the SCFI motors as well.  I'll let ya know how tight they seem when I install the MFI spider in a month or so (maybe sooner due to having my CEL pop on today, mostlikely due to a P0440 code again).  I might just decide to tear into the damn thing now instead. _____________________________ Kyle- 2004 Rainier 1970 Chevelle - Resto 1974 K5 Blazer - Resto (in reply to MNHawk) Post #: 20

Today's Posts
Most Active Topics
Make A Donation
Forum Rules & FAQ
RSS Feeds

Chevy Blazer Prices

Chevy Blazer
Trailblazer SS

Top 10 Posters
swartlkk 14472 drperry 3901 hanr3 3479 chevy lover 3411 m00nwater 3269 eurogoldls 3121 paddle_grl 2944 hillbillyino 2884 wolfpack 2823 xblazer01 2659

New Vendors
AMSOIL - Performance Oil Technology