hesistation at wot

[stevexr7sc]

hey guys what do you think? just put got the car from the exhaust shop and it sounds awsome but driving it home she bogs off the line and burns rich. there is a hesitation but kicks right back up. could it be the wrong sampling tube for the mass air? also the check engine light is on. if you have any ideas please let me know.
Thanks, Steve

[Bill McNeil]

Is exhaust the only thing they worked on? I'm thinking they may have damaged an O2 sensor possibly?

Tell me what colour sampling tube you have with what injectors and what size meter, and I'll tell you if it is the right size or not.

Do you have an EEC tuner? If not, you could be dumping fuel under WOT.

Could be a bad reading from a sensor, TPS, IAC, ECT?

Give us some more info.

[tbirdsc357]

also the check engine light is on

I say get it scanned to see what codes it's sending out.

[stevexr7sc]

Bill thanks for the response. I forgot to metion that I rebuilt the motor and then I brought it to the exhaust shop. As for witch colour the sampling tube is; is that I ordered it from scp and specified that I had 42# injectors. My car is an 89 cougar xr7 and has an egr fitting wit two O2 sensors. When I bought my Kooks headers they did not come with the egr fitting so I had to make my own on the headers. Would the placement of these fittings make a difference? Oh by the way the motor seems to shake a little but does not miss. What do you think?
Thanks, Steve

tbirdsc357 I will get the dealership to scan it for codes
Thanks, Steve

[Tazer999]

What is the sampling tube anyways? I was just wondering if I have the right one for my car

[SeanMatteson]

You mentioned the car seems to shake a lot. Did you replace the motor mounts at the same time that you rebuilt the motor? Perhaps you've got weak or broken mounts.

Regards,

Sean

[stevexr7sc]

Sean, I did not replce the motor mounts. They looked alright to me. I was going to chain/strap the motor down to see if it helps.
Steve.

[Bill McNeil]

Steve,

Scanning for codes should be first and foremost. As Sean mentioned, the shaking is most likely the motor mounts, regardless of what they look like. You may find if you jack the motor up a little from the pan, the mounts will actually seperate. They get weak from age, and weren't good quality to begin with.

If you have a 76 C&L, the sampling tube in your MAF should be colour coded PURPLE on the tip of the tube to make sure you have the right one. As for the exhaust work, if the EGR components were damaged during installation, that will effect the way the car runs, and will spit a check engine light.

VERY IMPORTANT: Does the hesitation/running rich happen only when cold, or all the time?

Tazer,

Unless you have an aftermarket C&L MAF, then ignore what I was saying about sampling tubes. Your stock MAF (if that is what you are using) is already calibrated from the factory and does not use sampling tubes.

[Tazer999]

Bill: I have a 76mm C&L and it has yellow on the tip of the tube. Is that correct for 30lbers?

[Bill McNeil]

Yeaup.

[stevexr7sc]

Bill, the colour is redon my sampling tube. I hope this is right for 42# injectors.

Steve

[SeanMatteson]

I thought the 42lb tube for the C&L 76mm MAF was coded purple.

[Bill McNeil]

That depends. Is your C&L the 76mm unit or the 73mm unit? Find out ASAP so we can confirm. This may be your problem.

[stevexr7sc]

Bill I have the 73mm C&L.

[stevexr7sc]

Bill the car does not seem to be running rich anymore, but the hesitation is still there. I'm going to bring it to the dealership tomorrow.
Steve.