Well I think my CPI is dying, ive been failig my emisions because of too many hydrocarbons, and my blazer idles really rough. I think one of the injectors is dumping too much fuel because i keep getting bank 1 too rich code and that would explain the mini-backfires (exhaust is going fine and POMF.bub.bub.POMF.POMF.bub.bub. etc)*yeah i suck at sound effects*

is there anyway i can find out of it truly is my spider unit that i need to replace without having to go to a shop or spend 3 hours and $10 on a new gasket to check it?

 

alright, well something else weird is going on too. My CEL is on for the too rich and its giving me p1406.

But the odd thing is, if i drive with the heat on vent mode the CEL goes off, WTF?

 

Yes your spider and internal fuel ines are probabaly shot,I just replaced them on my buddys 1995 4 door.It does not take 3 hours to remove the plenum,took me no more than 20 minutes to remove it and no more than 20 to put it back on after repairs.All you need is a 10mm deep socket and a T30 torx to remove the fuel line retainer on the back of the intake manifold and a few other basic hand tools...pliers etc...The fuel spider is expensive but money well spent as my spider was original and was leaking badly from not only a shot FPR but the poppet nozzle lines were leaking where they enter the spider and the fuellines and clips that hold the nozzles into the intake were brittle and if I was to remove them to replace the shot o-rings on the poppet lines the lines would probabaly break.So I decided to simply replace the spider.Also you probabaly will find the nylon fuel lines going up to the spider from the steel lines outside of the manifoldare also deteriorated and leaking,REPLACE THESE they are only 50.00 from advance and is also money well spent and you MUST replace them if you disconnect them from the spider as they WILL leak if you don't.After you remove the plenumlook at the bottom if the intake if you see "clean spots" in the bottom you have a leak for sure you may even see gas pooled in the bottom as I did.If you see gas in the passenger side the the FPR is/was leaking if you see gas in the drivers side then the lines going to the spider are leaking.If you cannot determine the origin of the leak or want to confirm your diagnosisturn the igntion switch to the "ON" position but do not crank the engine and look for the leak as this will pressurize the lines.If the FPR is the only thing leaking replace I reccomend replacing the fpr.If you replace the lines you will find a retainer that holds the lines into the manifold and a T30 torx bolt holding the retainer to the manifold,be careful when removing this bolt not to strip it as it is very hard to remove it if it is stripped.I reccomend buying a brand new good quality torx bit for removing this bolt as a good quality bit will greatly reduce the risk of stripping the bolt.Trust me it isno fun removing the intake like I had to do to remove the stripped out bolt on my buddies 94 blazer after he stripped it out because he used a cheap torx bit.After doing repairs before you reinstall the plenum turn on your ignition and look carefully for leaks,after you are satisfied reinstall the plenum.After everything is reconnected turn your engine over and you should have a smooth idle,your SES light may be on still if you didn't clear the DTC's also if you did you may have a new code pertaing to the TPS since you turned on the ignition with the TPS disconnected simply disconnect the battery to clear them,after this if there are no other problems your SES light shouldn't come back on.If you need any more help let me know

 

thanks a million, thats everything i needed to know. cant wait to do it.

 

Not for nothing, but the whole CPI replacement has been well documented in a HOW-TO located in the DIY section: Fuel pressure regulator on Blazer 4.3L CPI W engine (incl'd EGR and IAC clean/check

Its a bit easier to read than the post above...