minho78

MY money is on the TPS.

Richgreenster

I agree. I am going to test for boost leaks as well. I will keep you posted. I will have time tomarrow to test both.

max_boost951

There has been a previous thread on this condition and the problem was found at the battery cables. Positive battery cable insulation is prone to cracking and grounding itself on the bell housing from the stater. Heavy load running issues not enough amperage getting back to the battery. Worth checking and clean up your grounds on the bell housing.

cruise98

I had a friend with an NA that had similar symptoms. It would start sputtering at 3500 every time you ran it. Turned out to be bad speed and reference sensors.

Richgreenster

I am doing a pressure test and have a leak coming from the oil air separator. Is this normal?

Richgreenster

Here is a pic of the way that I am pressure testing my car. It cost me all of $2 for this set up. I am testing from the J-boot. I do have a leak at the oil air separator. I am wondering if this is normal and if it is a big deal due to the fact that it is on the intake side.

Richgreenster

Bump. bump pidy bump bump

Richgreenster

Pressure tested the entire system and found a hose had come off at the MAP sensor. I thought that I hit the jack pot finding this but the car still sputters and back fires at full throtle. I tested the TPS and found a weird spot in the resistance at half throtle. This fixed the car acting wierd at the half throtle spot but still the car does not like load. I also have a good air leak at th ISV electrical conection and at the Oil/Air seporator. Also My Heater will not switch over from off of hot. I am trying to figure this out as well. I do not hear any air inside the cabin.
Any help would be greatly appreciated as I am going to work on the car this weekend.

2.5L Just Rebuilt
Vitesse MAF
SMT6 piggy back. I do not have the test plug and need one to check this out. Any one selling or renting one?

Scott H

ISV leak you can fix with some JB weld, spread it around the electrical connector and where the casing is pressed in on the cylinder section on the same size as the electrical connector.

When you say you have a leak at the AOS do you mean air coming out of the oil fill hole? I wouldn't worry about it, that is normal when pressurizing the intake track.

Heater issue: heater clips?

Richgreenster

Thanks for the info. I am planning on taking the ISV out and can JB weld it up. As far as the AOS, I am not sure but it seems to come from the top area of the unit. I did not think that an airleak in this area would be a big deal but maybe it is. I have not been too woried about the heater issue but maybe it will not switch over because of a vacuum leak? It used to work before the motor swap..

fast951

Do you have access to a different DME or KLR boxes to try (if you haven't already)?

Have you examined the dat ain the PB to make sure nothing is out of the ordinary? I just spent time with someone experiencing rich condition, it ended up someone set the PB to always richen the mixture..

The 3000RPM is a bit of mystery. Can you go WOT once above 3000RPM?
Is the problem related to boost? WOT?

Try to narrow it down as much as possible...

Richgreenster

My wide band got stolen. Long sad story there... I need to get another one to see where the car is at as far as AFR. The car will run under light load but anything from medium or full load it does not like. It back fires and stumbles. Medium load it will run to red line now but under full load it will stumble so bad that it will not even run past 3000 rpm. I did not change the PB or even open the floor area when I did the motor.
I am wondering if the air leak at the Oil/Air separator is bad enough to cause this. Also the leak at the ICV is fairly bad.
Can I run a hose from the intake manifold to the intake pipe directly bypassing the ICV? In other words totally bypass the ICV to test this leak.

Also in the SMT6, I am running map A and map B which I can switch very easily. In map A and B, most of the boxes had a '3' in them. It seemed to run the best with this adjustment. Now I have '0' in all of map A and left map B alone still with the '3' The car still seems to run a little better with map B. Map A with the 0's makes it worse. If I change the boxes to 5-7-9 etc it still will not run any better. 3 seems to be the magic number even in its current sick condition.

fast951

Rich, You have multiple issues. One is a voltage drop on MAF signal between sensor and DME. More than likely due to the wiring or the solder points, seen it many times, no big deal.. The "3" is compensating for the voltage drop. BTW there are better ways to do accomplish to accomplish this.
Ideally you want a clean path to the DME, but this is not the main issue you are battling now.

Considering the car ran fine till you performed some engine work. Did you double check ALL the wires to make sure nothing was damaged by mistake? Take a data log in the PB (keep it short), maybe it shows something to point us in the right direction.