OK, here is the low down... Im just gonna explain everything I have done... Im so freakin fed up with this car. OK, ready.

THE PROBLEM... My car sputters when I give it any gas. When I start it up in the morning, it runs like it has a cam for the first 30 seconds I have the car on and in a gear. At idle its fine. After the 30 seconds it coasts good, I then give it any gas and it misses and pops with more than 5 percent throttle. I have power braked and there is a stead stream of power which from what I have always believed means that the plugs and wires are fine. I talked to a mechanic and they said that when I put the plugs in I might have fractured the porcelain in one of the plugs... There is no arcing, I have checked at night with a mist of a water bottle.
This is what I have done to correct the problem


93 Transam Automatic transmission.

Replaced: Within 1k miles ago.

OPTI
MAP SENSOR
COIL
Ignition Control module
PLUGS, WIRES
TPS SENSOR
IAC
COOLANT TEMP SENSOR
WATERPUMP

Mods...

Ported Throttle.
Home made ram air.

P.S. This happened about a week after I did the plugs and wires, since that I have replaced the opti, waterpump, iac, tps, coil, and ICM.

 

Do you have the ability to scan it for sensor readings? How old are the O2's? Scanning can tell you about them.
What's the fuel pressure especially after the engine is shut down? Does the FPR vac hose have fuel in it? It could be loading up from fuel leaking into the intake and it takes some time to burn off after it's been sitting for a while. That could be by a sticky injector or leaking FPR.

Another thing that you can do is look for a dead cylinder. An infrared thermometer on the exhaust manifold is helpful. Pulling a plug wire or injector plug can be a good substitute. If a missfiring plug is suspected, have the engine put on a scope. Doesn't cost much and is quick too.

I would test things before throwing any more money at the problem.

 

Did you think about that maybe you crossed a wire? I did that once. Marked all the wires and some how I still missed matched 2 of the wires. My car did the same thing that You are saying. Try looking into that. I swore I had them right and yet I still had 2 crossed.

 

Sorry, I thought I put everything in the first sunopsis..


I checked the FPR, it has no fuel. I checked the fuel pressure. It is at 38 and when I rev it up it stays right at 38 psi.

I will look with the infared thermometer.

Also, I just put Bosch O2's in there about 4k miles ago and that was after I seafoamed it.


Any other suggestions.


Tim

 

1 more question. Should I have a constant 38 psi when idle and WOT.

Tim

 

Pressure should go up at WOT and higher engine loads.

 

So what does the FP do when you shut the engine off?

 

The fuel pressure stays constant for 5 mins or so and then starts to release


Tim

 

Since the pump is no longer running, pressure eventually bleeds off. A check ball in the pump holds pressure for a time, but not forever.

 

here is my vote:
o2 o2 o2 o2 o2 o2 o2's!

 

I too would say O2's, especially aftermarkets. However his worst problem is during warm up and the PCM ignores them while it's in open loop. BTW, never use anything but OEM O2's, I never could get Bosch to work. I've been told that aftermarkets are made with a wide operating range and in a lot of cases, are too wide to work in a particular application.

So that leaves us back to WTH is the problem? Have to think about this for a while. Rob? what do you think?

 

If it started doing it right after you did plugs and wires, I would concentrate on them first. Your poor running at startup could be a leaky injector, too.

 

I will work on this and hopefully have an answer for you, or at least try to narrow it down to something else by this weekend. I plan on changing the plugs and wires this week and maybe getting datamaster on the car from a friend on a local message board here in tampa.

Tim

 

BTW, what are the Part numbers for 93 O2's. Keep in mind that they arent heated, or can someone give me jason kromer's number.

Thanks


Tim