HT4100 4.1, 4.5, 4.9 Discussion, So how old is too old for injectors? in Cadillac Engine Technical Discussion; I have an '88 Eldo and it idles kind of rough. I've checked most everything else. The car has new ...
I have an '88 Eldo and it idles kind of rough. I've checked most everything else. The car has new cap and rotor, new plugs, good quality plug wires, new fuel filter, throttle body gasket, EGR checked and new gasket, throttle body cleaned, vacuum tested, new ISC motor, Min idle speed checked, timing checked, TPS set, ISC plunger set, No codes coming up, did I miss anything?
Oh, fuel pressure regulator. Did that too. LOL
Anyway, I've thought about getting the injectors ultrasonically cleaned because it is relatively cheap compared to the cost of new injectors. But since these injectors are probably original to the car, is it worth it or should I just buy new and be done with it? There's only two and they're like $80 apiece.
Injectors are electro-mechanical and wear out like anything else--the coils fade, the springs wear out, the pintles clog up, etc. Having said that, TBI injectors are typically either work or don't, and the computer will compensate by varying the pulses for the most part. If they are working the best reason to replace them is to reset the maintenance timer. They are increasingly difficult to find and in a few years will be very hard to get new. I doubt you'll see or feel anything from it
As for stuff on your list, you might want to consider a high-flow cat converter.
Thanks for the advice. I appreciate it. I've wondered about the cat for some time, but was told that it would be pretty obvious if the cat was bad because the car would have no power. The O2 sensor data looks normal and the cross counts seem OK.
It does feel like the car is "fighting it". Like there is resistance in the exhaust. The car started and sputtered badly for several seconds today when it had been raining hard. Then it cleared up, but still idled rough (like usual). The RPM bounces around 25 to 75 points and is never steady. I put a timing light on every wire and I don't see an obvious miss, but I'm no expert.
I've changed the fuel filter twice. The second time after using Redline injector cleaner. That might have been a waste of money, but hey, just in case.
I can even feel the inconsistency at highway speed. I think the word might be "chuggle". I'm not sure what the MPG should be, but I'm getting around 21 MPG on the highway, and maybe 17-18 overall.