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Discussion Starter #1
Hi guys so my 96 giving me issues
If I fast throttle the car when at idle it bogs like it will not want to rev up sometimes I take back fire. If I eas into throttle then it’s ok

Not sure if it’s Opti or maf etc any help would be great
 

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check fuel pressure "when" the problem occurs. Get a FP gauge with a hose on it you can tape the gauge to windshield and monitor FP when you drive...especially when you slam WOT...
 

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Discussion Starter #5 (Edited)
loading a video now to show the back fire intake


there is no check engine light on or current dtc



when scanned old dtc in history it shows



these 2



 

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sounds like the engine has a exhaust restriction .. remove the upstream O2 sensors see if it still does it .
 

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Discussion Starter #7
sounds like the engine has a exhaust restriction .. remove the upstream O2 sensors see if it still does it .


I will check but I don’t think so I think it started after engine wash


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I think it started after engine wash


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...the plot thickens.

By chance is this why you are also looking into Opti purchase in your other thread?

Getting back to engine wash...assuming water was involved that can get into several electrical items....as well as Opti. If the later this can be cleaned out but requires taking Opti off/apart.
 

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I will check but I don’t think so I think it started after engine wash
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removing the 2 O2 sensors is less time and $$$ USD than playing around with OPTI ..
OPTI distributors today is a crap shoot .. probably have better luck at casino than OPTI purchase .

there are members on here that may not agree with me but IMO never wash this engine down with a water pressure of any kind ...

my other engine the 5.3L GM truck engine that also does get damaged if washed ..
 

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You guys are watching to much csi

Yes I am asking in other post about intake back fire issue

Yes I am preparing to order a new opti since they go fail

This post is asking the difference between 2 options from Delco


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I will check but I don’t think so I think it started after engine wash


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Between the two Opti's you posted from RA, I and 1Slow suggested the 1st one

No CSI thoughts here...just trying to offer some help

Apparently neither AC Delco Opti is available now at RA

When you stated this issue started after you washed your engine...I suggested you just open the Opti and clean it. When oil or water gets inside the Opti causing intermittent issues cleaning out that crud typically resolves the problem. Recommended you check the function of the vent hose harness also as any water (coolant is sticky) or oil inside Opti gets sucked into vent hose clogging the VERY small passage in the check valves inline.

Given any available Opti now is a 50/50 crap shoot....and if your current Opti is a original AC Delco you should consider cleaning out the potential water contamination it may have gotten during the engine wash. If cap and rotor have 100k mi on them, get the MSD C&R

Yeah your Opti "could" be failing electronically but given your engine wash comment and subsequent ignition issues...I would suggest cleaning the Opti to see if that resolves (likely) your issue. You will immediately see if crud got inside once you open it
 

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Discussion Starter #12
IMG_0947.JPG IMG_0948.JPG IMG_0950.JPG IMG_0951.JPG


Have all apart now looks like someone was in here just before I bought car . Wp looks new Delco unit and spins tight .

I think not going to touch timing cover gaskets etc for now same with wp

But I do like to ditch the air pump what a pain it is . Do able on my 96 that won’t be emission test with obd port not setting code ?


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...did you take rotor off and then that mid plate and look "inside" the opti?

I see water drops on the cap...or did that happen somehow after you took it off?

It looks like a "non AC Delco" Opti....which in itself could be the problem


Air Pump: you need to program out the air pump on 96. There was a TSB way back the dealership would do the computer re-flash, pull relay and plug air pump outlet. You can delete it if emissions is not a problem for you.. You will have a CEL on if you don't re-program the PCM
 

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Discussion Starter #14
It’s oem I say symbol for Mitsubishi on sensor

It was dry inside outside slash from Coolant clean up .

I did order new cap and rotor kit oem




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Discussion Starter #16
update

last few days working on car
problem still there

i have done new cap and rotor oem delco
new wires and new plugs
new fuel filter

car does start up better and nicer idle forsure

my next step is to look into o2 sensors i think we have 4
they are cheap so might just get all 4 are they all the same part number?

also thinking MAF is maybe acting up from the k and n filter cleaning. i did let it dry with light amount of oi for few days but maybe it got onto the maf element

will check with mini camera to see how cats are
 

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The Manifold Absolute Pressure sensor is a very reliable part, but the rubbery nipple which seals it to the intake manifold is known for shrinkage and becoming brittle. About as inexpensive and easy to replace as it could possibly get.
Fuel Pressure Regulator is another very inexpensive and easy-to-replace part.
The EGR Valve is also inexpensive, but a bit more difficult to replace.

Be sure to clean the MAF sensor with electrical contact cleaner, or any cleaner specifically suited for cleaning MAFs.

If those don't do it, the only remaining guesses I can think of are, intermittently variable wiring, some subtle EVAP charcoal canister system fluctuations, and intake and/or exhaust manifold leaks.
 

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nothing bad with that opti . looks very new...........so when you put it back sh*t can happen if you screw it up.. not all that easy to get it set in place..


so rather than check for the restricted exhaust which is easy and less time you did the opt ... good luck on re-installation..


dist cap looks like 2K miles on it...
 

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Discussion Starter #19
it was ok dizzy and cap but didnt mind getting new for piece of mind.

next plan is to get some maf spray and also new o2 sensors they look oem

might also get new fpr
 
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