Okay so I just rebuilt this engine and I am stumped to this point. I just replaced the IAC and TPS and air charge sensor. Engine will flood, has high idle, which my rpm tac is stuck on 2500 rpm and has been for a long time so I cant tell what rpm I'm running anyway but I know it's high. But it will also try to die when I give any amount of sudden throttle. I did not tamper with the screw on the throttle body that the tps goes on top of it is still at factory setting. I've tried resetting computer also. It is running rich too. Which I know the IAC is working correctly I disconnected it and engine died so it should be working. Anybody have any clue on this?

 

Did everything work correctly before the engine was rebuilt? If so pull codes and check fuel pressure, if not pull the pcm and look for blown capacators.

 

everything worked before I rebuilt it. Only reason I rebuilt it was because the rear main busted and my head gaskets busted too. Took the heads off and engine was nasty I could flip chunks of carbon and ring sealer off like hamburger patties from how the people treated it that I bought it from that stuff will ruin your intake apparently. But I honestly dont know how to check codes and I know I'm having an o2 code because I've just got it shoved in the exhaust because I havent put exhaust on it yet. Still tuning it and it has open headers. But that shouldnt cause that I dont think. Didnt start till I changed tps sensor. Before i changed the tps sensor. With the old one it would idle until I gave it any amount of throttle period after initial startup. After I put new tps on is when this started.

 

Get yourself an Equus 3145 code reader.. $20 on amazon. Also double check all wiring connections to make sure something isn't loose. Where did you disconnect the engine wiring when the engine was pulled?

 

disconnected everything from the engine and pulled the engine raw. So all the wiring stayed in the bay. The engine is my senior project and I believe this is the last problem I have at the moment besides an coolant leak and it's got me confused but I'm a little more worried about it running right now than the coolant leak. Is there any way I couldve put the tps on wrong?

 

Ok that is good. Did you change anything inside the motor or is it all stock? Did you set the distributor to TDC on #1 compression stroke before firing the motor the first time?

 

Put a 278 cam in it I believe I dont really remember. Not too big of a change to have to flash the computer since the stock is 248-254 or something like that. Timed it to spec. Turned crank so its 10 undersize. Honed engine and oversize rings. Everything checks out like it should. Deleted egr and completely removed smog pump and all components related to it. Capped the vacuums that were left over from deleting them and added the correct resistors to match the voltage the plugs needed to keep from throwing a code through the computer. Has brand new valve train also. I'm thinking there was some way that I put the tps on wrong somehow. But i have no clue how i wouldve messed that up, I only started having this problem yesterday when I put it on. The only sensor I havent replaced is the map sensor. Everything else is new. Disconnected the battery and let it set about an hour or so also to let the adaptive memory reset. So I'm completely blown as to what I did wrong.

 

Actually that is a hugh change. So this motor has been running "fine"? It's not going to idle like stock with that cam.

Resistors? You have a couple red flags there but it shouldn't stop the engine from running.

Could be the sensor is bad, electrical components are a complete crap shoot these days. Why did you change it again?

Map sensor could be a problem but at this age so could the PCM.. is it original or has it been replaced somewhere in the past?

 

original. Built it for my senior project just running into this last problem.

 

You built the PCM?

 

No I read that wrong I thought you meant the entire engine I just built the entire engine. The plugs that relate to the smog pump and egr are the ones I put resistors on, except for the plug to the egr itself, I bought a simulator and plugged that in. I think they call for like 5 watts. So I put 75ohm, 5 watt resistors on those plugs to keep from tripping the computer that's the only thing I put the resistors on and the only reason why I did too. I think it was just 3 plugs. But the engine was running before I replaced tps. Before I replaced it the mixture seemed good and when I would just start it and not touch the throttle whatsoever it would run and idle fine. But as soon as it got any amount of throttle it would just go straight crap shoot no matter if I was in park or in gear. Spit and sputter and then die after a minute unless I kept a constant throttle on it it would also sound like someone was tethering the throttle in and out when I drove it and gave it a constant steady throttle. And now that I've replaced it. It idles but it idles kind of high, and smells extremely rich. And any amount of throttle I give it, it will be fine until about half throttle and then it hesitates and tries to die, but if I let off the throttle that instant it tries to die, itll hesitate and then go back to the high idle. But if i give it any sudden throttle. Say I just give it a sudden in and out quarter throttle. Not even that really. Itll hesitate and sounds like a misfire or something. It sounds like it just shuts off and starts back instantly like within 1.5-2 seconds. But after that it's back to that high idle. Its parked kind of on a hill. And I'll give it about half throttle to climb it, itll hesitate and die. But if I give it maybe quarter if I ease into it itll climb right on up. But its same way on semi level ground also.

 

Also itll flood if it is shut off and I try to crank it right back up. And still has that extremely rich smell. Strong enough to make my eyes water and give me a headache.

 

I think you need to get at least some exhaust on it, and that TPS is probably bad so I'd suggest putting the old one back on. The cam you put in is going to cause a lot of problems but an exhaust will settle the motor down a bit, after about 30s to a minute of running the motor wants to go into closed loop and for that to happen the O2 sensor has to be present in a sealed exhaust that is long enough that no fresh air gets at it.

 

so it's not possible that I couldve out the tps on wrong is it?

 

Coolant temp sensor or fuel pressure regulator could cause flooding problem.