Engine Part???
#1
11-30-2008, 07:37 PM
Engine Part???
I am new to Blazer ownership. I have a 2000 2dr 4x4 4.3 V6 130,000 miles. I have a random miss fire on cylinder three according to the computer. My mechanic told me i need to replace the fuel injector spider. Just what is this part?? It looks like a 6 legged spider.
#2
11-30-2008, 08:12 PM
RE: Engine Part???
How did they come by that diagnosis? When was the last time there was a tune up done to the engine (plugs, wires, cap, and rotor)? Did they even bother trying to remove plug #3 (which can be somewhat problematic on some models)?
To answer your question, the "spider" is the fuel injection system internal to the engine. The SCFI motor used from 96 thru mid-02 has a central injector pack which houses the six individual electronic injectors. These injectors are then connected to nylon lines which direct fuel to pressure actuated poppet nozzles located in the intake runner just ahead of the intake valve.
The poppet nozzles can be somewhat problematic and an upgraded MFI spider used on the mid-02 to 05 s-series trucks is available. The newer MFI spider moves the electronic injectors out of the central housing to the end of the nylon lines, replacing the problematic poppet nozzles.
If you search using the keyword "MFI", you should find the part number for the AC Delco part as well as what to expect for a price. It is not difficult to replace, but the lines on top of the motor can be a pain if you do not have the proper tools. But ask the mechanic questions. Often, they are all too quick to throw unnecessary parts at a problem without properly diagnosing it first. All at your cost!
To answer your question, the "spider" is the fuel injection system internal to the engine. The SCFI motor used from 96 thru mid-02 has a central injector pack which houses the six individual electronic injectors. These injectors are then connected to nylon lines which direct fuel to pressure actuated poppet nozzles located in the intake runner just ahead of the intake valve.
The poppet nozzles can be somewhat problematic and an upgraded MFI spider used on the mid-02 to 05 s-series trucks is available. The newer MFI spider moves the electronic injectors out of the central housing to the end of the nylon lines, replacing the problematic poppet nozzles.
If you search using the keyword "MFI", you should find the part number for the AC Delco part as well as what to expect for a price. It is not difficult to replace, but the lines on top of the motor can be a pain if you do not have the proper tools. But ask the mechanic questions. Often, they are all too quick to throw unnecessary parts at a problem without properly diagnosing it first. All at your cost!
#3
11-30-2008, 10:31 PM
RE: Engine Part???
Thank you for you answer!! A tune would seem to have been done very recently. It's a new truck to mehowever.The guy i got it from said it had just been tuned up. The check engine light came so i took it in and they hooked it up to the computer. It showed miss-fires on cyl 3. He then took out the plug from cyl. 3 and it appeared to benew. He then looked in to the area where the spider is and there was excessive fuel in that area. He showed me the computer with the engine running and showing miss-fires on cyl 3.
#4
11-30-2008, 10:45 PM
RE: Engine Part???
"excess fuel in that area"... What does that mean? You can only see the very top of the spider with the upper plenum installed.
If it is leaking external to the plenum, I would suspect the o-rings in the feed/return line connection.
If it is leaking internal to the plenum, then you may only need an FPR (fuel pressure regulator) which is much cheaper than the whole spider. An FPR would be more likely to cause a cylinder 5 or 6 misfire than a cylinder 3 misfire though. Heck, it could be a leaky o-ring which would be very cheap to fix.
If the injector or poppet nozzle on cylinder 3 is at fault, you can replace that one injector if you are on a tight budget, however, you may not get the results you had hoped for as the other 5 injectors would not be flowing as well as the one new injector.
I am just trying to make sure that you need to replace the spider. It is an expensive part.
If it is leaking external to the plenum, I would suspect the o-rings in the feed/return line connection.
If it is leaking internal to the plenum, then you may only need an FPR (fuel pressure regulator) which is much cheaper than the whole spider. An FPR would be more likely to cause a cylinder 5 or 6 misfire than a cylinder 3 misfire though. Heck, it could be a leaky o-ring which would be very cheap to fix.
If the injector or poppet nozzle on cylinder 3 is at fault, you can replace that one injector if you are on a tight budget, however, you may not get the results you had hoped for as the other 5 injectors would not be flowing as well as the one new injector.
I am just trying to make sure that you need to replace the spider. It is an expensive part.
#6
12-09-2008, 05:41 PM
RE: Engine Part???
Well as it turns out I took it to another shop and it has nothing to with fuel injection. The number three cylinder only had 75lb of compression. Seems to be a burnt valve. It's being repaired right now. The shop said they have had a hand full of these this year. He said that was kind of odd. My question now is what can I do to keep this from happening again?? The mechanic said it's all controlled by computer now and there is really nothing I can do.
#8
12-10-2008, 03:44 PM
RE: Engine Part???
EL8232, do mind me asking how much they are charging you? Im going back and forth on whether or not to sell mine. I have a similiar problem with cyl #5 compression is 80lb. It ticks.knocks like crazy but still runs well. Gas milage is down to about 15mpg.