89 Daytona Idle problem
 

Hello i am new to the fourms i have a 1989 Daytona ES base with a 2.5TBI vin k non turbo engine. the engine is stock and i got it about a year ago. just got a new floor and sub frame wielded in was rotted out. The engine runs good cept for when it idles. once it warms up it idles rough and sometimes stalls out but then starts right back up no engine check lights on, no error codes listed with the on-off-on-off-on ingition check. I have replaced the EGR, MAP, Vaccum lines, dist cap, rotor, plugs and wires, air filter, oil change, and all the sensors cep for internal ones and coolant temp and fan switch. there is a ticking from the top of the motor could be valves or wrist pin not sure but once your driving at 30+ it sounds and runs smooth as butter. just idles crappy. any ideas?

Did you pull the end of the wires through the dist cap with pliers?

Not real familiar with your particular engine, but I know of other fuel injected that employ a controlled vacuum leak to help the computer regulate idle speed. I believe it's called an Air Injection Solenoid? Should be on the throttle body with wires going to it. Perhaps it's failed or plugged. I would also try running a few bottles of fuel injection cleaner through it, worked wonders on my 94 Ram.

Yea the wires are fully inserted in the dist cap, i've run fuel cleaner thru it before, it does have a idle speed motor on mine which i havent replaced yet due to having to take the tbi off the engine. i did buy a tbi rebuild kit for when i do remove and replace it (one of the few eletronics i havent replaced) i also replaced fuel filter, and most the lines one the rubber hoses on the injector was cracked so now it has way better fuel pressure then before. Since i'm unable to rebuild the tbi at the moment i also ran carb cleaner thru it and the throttle plate and cleaned off the idle gate by the motor. it idles good til it fully warms up i read on the mopar website the major problem with the 2.5L vin K non turbo was it had a very bad air intake problem due to having to suck so hard to get air in. i'm thinking or putting a high flow k&n and rerouting the air pipe to be more straight since it runs so good cold.

Is vacuum constant and what is the reading?
Remove the brake booster and plug the hole. Re read vacuum.
If you cant find an open source gasket leak look for a device or sensor that calls for vacuum and see if its drawing air.

Next. Read the voltage at the TPS sensor. The computer is blind and cant tell throttle position unless TPS sends a specific voltage at closed throttle and then varies voltage with throttle openings. Should be three wire TPS. 12v, voltage (signal) out and ground. What is voltage out at closed throttle?

While you are there crack open the throttle blades and clean the lip that the blade rest at. If she is hanging open it will hunt idle.

If warm it runs rough? The computer works in different profiles. Start, run, warm up, etc... If the temp sensor is off, it will stay in enrichment cylce (warm up), then she will run fat with fuel when it doesn't need it. You didnt change that so test it.

my brother had a Daytona 2.2 i think it was a 2.2 and he replaced every thing with a mopar performance carb ignition intake kit totally eliminated the emissions systems check it out if possible

i replaced the throttle poistion sensor, i dont have tools to gauge the suckion or volts of anything just a 'backyard mech' so i dont know how to do alot of things. in park it idles perfect it's only when in drive it idles rough, i havent replaced the mass air sensor, coolant sensor or temp switch yet i'll porlly do those soon. could be the idle vavle starting to go out but i gotta take the tbi off the car to get to it which is a job for anorther weekend since i already got the rebuild kit with new seals to do it no point in taking it off and now fully cleaning it. it's started to cut out at red lights, and drive thrus but starts back up right away just very annoying and could be dangours with a moron who doesnt know your not moving yet and rear ends you.

so the only sensors i havent replaces yet i believe are Knock, Fuel Regulator in the tbi, Air charge, Coolant temp, temp switch, Oxygen. i also read there is a deceleration fuel cut off relay on the car I'm not sure if that could be causing it or not either.

have you cleaned the throttle body & ais ?

Yep i have, but right now car is sitting blew the engine. all the sensors say it's fine but loud rattling coming from upper cynlinder head by 3 and 4 and before that happened gave it a compress test and was 90 90 60 30 the top three picks are blew a cam bearing (but oil pressure is normal) Broke a valve which would go thru the piston also, or the wrist pin broke. I think tho i blew the vavle stem seal and it's bouncing around in the engine. But i'm taking it in at the end of the month and having the engine overhauled

there are no cam brgs in that engine , the cam just rides in the alum head
I am sure you will find the problem once the engine is torn down