my 98 cav's lock up torque converter went bad a year ago. i parked it. finally this summer i got around to replacing it, and ever since the car has been missing through out the driving range at part throttle only. at wot, the car drives perfect, but when you are just cruising at a constant speed, or accelerating lightly, the car will start hesitating / missing. it's very speratic. i swapped spark plugs (and gapped them correctly), plug wires, and coil packs. same problem. so i swapped in a new o2 sensor. no change. and now today, my cel came on, and the temp guage dropped to nothing. checked the codes, and it was giving me P0118 (cts high circuit). well cleared the code, and the guage started working again. after a couple times driving it, it happened again though and it through the same code again. put in a new coolant temp sensor, and it's still doing the same thing. i hooked a fuel pressure guage to the car, and drove it around, and when the car misses or hesitates like usual, it never did affect the fuel pressure. so not sure if it's a fuel problem or not. i went ahead and replaced the fuel filter to make sure but that didn't help either.
the car has a 2200 w/ 4t40e trans. any ideas what else to check? i even swapped the computer with another 98 4 spd car. same issues, so the computer isn't bad. i used an ohm meter and checked the cts sensor wire and checked it at the computer connector also, and it's making a good connection. i'm about to roll this car off a cliff or set it on fire
thanks guys
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also, i searched for any and every post pretaining to 02 sensor malfunction, cts sensor, part throttle missing, hesitation, etc. nothing helped. i also don't have a catalytic convertor, so that's not causing it.
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There is a service bulletin from GM for bad electrical connections on the fuel injectors. Check the connections on the injectors and put some contact lubricant on them. I don't say that is your problem but it's worth a try.
A while ago on my '93 2.2 I had a problem where the engine would miss at low throttle settings, on the overrun mainly i.e. not accelerating or decelerating. It was fine at wot and showed no codes.
The local garage correctly identified it as a Crankshaft position Sensor, a new one transformed the car.
Not saying this is your problem but food for thought.
The OBD-2 code for the CTS from a web search says circuit shorted high, but no info on what to do to fix it?
Have you checked the ground-is there a separate wired ground from the CT sensor on yours?
Alont
thanks guys. i'll try the injector thing today. And I never thought about it might being the crankshaft position sensor, but it very well could be. i guess i have 2 issues. one is where it misses at part throttle only. at idle and accelerating, it drives perfect. it's not throwing any codes for that. and then the other one is where every once in a while it'll throw code P0118, and my temp gauge will drop to nothing. Or do you guys think I might have a wiring problem and it's causing both?
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Sounds like a stuck injector or bad connection to one. Had that problem before. Mine was gummed up, took them out, cleaned, perfect again. Could be the same thing.
well i went and got a crank position sensor. and it's still missing/hesitating. luckily for the 2200, it's only 13 bucks.
thanks for the response CTS. I'll go and put the fuel rail and check em. If they were dirty, would it affect the fuel pressure any? cause when i hooked the fuel pressure gauge to it, it all checked out good while driving. i even left it hooked up after i pressurized the system, and came back 20 mins later, and it only had dropped 2 psi, from 45 to 43. could that mean a leaking injector or is that about right for the pressure to leak off? the car isn't hard to start when hot though.
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u said you put a lock up toruqe converter in. you mean you pulled the trans?? if so did u pinch a wire? just an idea i know its not hard to do wires always find there way to were they dont belong when your working on a car.
naw on the 4t40, the torque convertor solenoid, and all the shift solenoids are in the valve body located behind the side cover. So I just removed the tranny mount, and dropped the trans/motor enough at an angle to take the side cover off. replace the solenoid and put it all back together. didn't even have to drop the sub frame. Now I'm not throwing any transmission codes. Before I was throwing 3. And the dealership said they all pointed to the torque convertor solenoid going bad. So i think that problem is fixed.
I did pull the fuel rail, and the injectors were spotless. I went ahead put it back in, and sprayed some contact lube in the injector clips. No change though
Still a part throttle miss. I'm about to say forget it and do a 3400 DOHC swap
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talked to a mechanic friend, and told him what it was doing, and everything i've done/replaced. he's thinking it could be a bad knock sensor, or egr valve. would either of these cause part throttle missing/hesitating, but other than that perfect idle, and wot performance? AND not set a code?
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Seach for a message I posted a short while ago "2.2 stalling - final fix". The sysmptoms you describe are exactly how my problem started out. Crusing or light acceleration stumble or miss. OK at idle, ok on moderate to hard acceleration, ok during parked idle or parked reving. After many months it eventually worsened until occasional stalling started to happen. I also spent a fortune on all the same parts as you - and more. Found a corroded wire connection for the injector power wire - effecting all 4 injectors, causing momentary power loss to injectors. Never gave a CEL code. An engine swap would not have fixed my problem. Problem was at splice where injector harness comes out of main engine harness. At the back of the engine, right on top of the transmission, near aft left side - just down below the fuel pressure regulator/EGR area - kind of near the coil packs. Very bad to get at - but might be a suspect as it seems you may have rescently disturbed the wiring in this area.
To try and prove or disprove - try what I did. With engine idling, use a long screw driver to poke and prode at the injector harness, wiggleing in all directions, from the left side of the intake manifold, all the way down to the main harness at the back of the engine.
Good luck. After I bypassed this wire - the car once again runs like a charm.
Thanks for the response Mike. I will defintely check out the injector wiring. I was kinda leaning towards it being a wiring problem. Especially since it's very intermittent. Some days it never does it, other days it might just be a slight hesitation, and then there are times when it just feels like it's about to die, then it speeds up, then it feels like it's going to die again. jerks you all over the place badly lol
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I too have a 98 cavalier 2.2 that started out just hesitating every once in a while. Within 6 months it got much worse. At least now I got 2 OBD-II codes PO335, and PO341. Both the crankshaft and camshaft position sensors. I replaced both of them and the car doesn't hesitate anymore. I hope this helps you out.
Oh one other thing, the longer I went, the more defining the problem was, it went from every once in a while to every right hand turn. Then, after replacing a ton of parts like you have, my computer finally gave me the right codes.
