My 89 Camaro w/ the 305 TBI engine has started bogging on me occasionally over the last 3 or 4 weeks. It's probably only done it four or five times, but this is what happens. Sometimes I'll be idling and it'll suddenly lose RPM and start to shudder a little, then it'll catch itself and start idling normally. Also, while I'm driving at constant speed it'll suddenly lose power and the RPMs will drop. I'll push the pedal farther and I can hear the engine working harder but the power is just not there. Then I'll push the pedal probably around 3/4 of the way down and the power is instantly restored and I can hear the engine working harder (like it should) but the tone changes and the power is restored.

The car has 142k miles on it, I've had it since 125k and I've never changed the fuel filter, and I don't know when it was done last. Could this be a possibility? Are the injectors clogging? Is the filter on the fuel pump maybe clogged up? Perhaps the filters in the fuel injectors are clogged?

Does anybody have any idea what could be causing this? Last time I looked at my fuel injectors spray, the pattern was conical, but it has been a few months. I'm also not getting the SES light at all.

Any help or ideas is appreciated,

Jason

 

btt

 

Come on, somebody has to know this. . .

Jason

 

Sounds like a vaccum leak. Have you check for a leak? Or possibly EGR valve. Getting any codes?

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'87 Trans Am:
(Engine)
305 TPI
160 Degree Thermostat
TB Bypass
Accel 300+ 8.8 Racing Wires
Accel Super Coil
Bosch Platinium Plugs
Custom Ram Air with K&N
Removed Emissions Equipment & Cat.
(Stereo)
Kenwood Excelon

 

Man change that fuel filter A.S.A.P. I'd bet that's part of the problem.

------------------
'87 Trans Am:
(Engine)
305 TPI
160 Degree Thermostat
TB Bypass
Accel 300+ 8.8 Racing Wires
Accel Super Coil
Bosch Platinium Plugs
Custom Ram Air with K&N
Removed Emissions Equipment & Cat.
(Stereo)
Kenwood Excelon

 

Fuel filter is most likely next i would have to say fuel pump could be going bad but change the filter 1st!

 

Jobryan: I doubt it's a vacuum leak, it doesn't exhibit the characteristics that a vacuum leak does. No, I haven't gotten any codes yet.

I think I'll check the fuel filter as soon as I can, if it's not that, I'm assuming it's the injectors or pump. . .

Jason

 

The fuel filters are directional. If thats not the prob it could be the fuel pump (use a pressure guage and drive around with it under your pass side wiper so you can see it)

If pressure was good the next time it cuts out, suspect the ignition pick-up coil. Even if it tests good, it could develop an intermittant open thats impossible to find.

It's not worth changing the fuel pump if thats not the problem.



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'88 Camaro RS 2.8L
'88 Formula 350 (Too many mods to list...)

 

my friend's tbi had a similar problem and it ended up being a bad injector. The way we went about finding the faulty one was listening for too much noise, looking at the spray pattern, and putting in a new plug on each side to see if a cylinder was running too rich or lean.

 

I've had the same problem twice now. Once it was a broken valve in my carb. The other it was my piece-o-crap 700R-4 tranny. They are prone to problems after 130k miles, so you might wanna have it checked. If it is slipping you will get fluctuating power to the wheels.

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---Grady---
1984 Berlinetta.
LG4 305, 170 hp.
Rochester Quadraje(Comp. Controlled)
TH-700R4.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock signature series air cleaner -w- K&N Filtercharger.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

 

Trigger: Thanks for the info, but my car is TBI and it has a T-5.

I'm just gonna see if the injectors look like they're spraying conical sprays and change my fuel filter.

Jason