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iTrader: (11)

The Main ECU can cause a variety of issues. From small things like running rich, to rough transmission shifts. Repairing the ECU will rule out an handful of things.

Ali SC3

iTrader: (10)

yes there is a sure way to tell if its your fuel pump ecu or not.
Test 1. does the car start.
if the answer is yes then your fuel ecu is working.
Test 2. does it drive/idle well
if the answer is no but it runs then its main ecu or a dozen other things.

tftimm

UPDATE and a question:

Last weekend, I put in Chevron Techron Fuel System Treatment when I filled up. Last night, took it out for a drive on the highway, cruising along at 75-80mph. Here are a few things I noticed:

1) Cruising, it is fairly smooth. It is accelerating on the on-ramps is when you can feel the hesitation. The hesitation doesn't seem to be as bad since I put in the Techron, but that definitely isn't the main problem.
2) The hesitation is only on acceleration. The idle is more noticeable in Drive and when stopped then when I shift it to park.

In reading other posts, here are a few other things that make me think it is the engine ECU and not the fuel ECU or other problem.

1) Randomly, when shifting the car from Park into Drive, the shifts would be hard. This has been going on for a couple of months and randomly, definitely not all the time.
2) The car always starts right up. In reading, usually the fuel ECU causes problems starting, etc.
3) When revving the engine while in park, you hardly notice the hesitation. It is almost always when driving and when acceleration, more at low RPM's.

Before I go spend $100 on an ECU, where do you recommend I can get a credible re-built or reliable ECU? I have checked E-bay and that is probably my best bet, but any recommendations? How much more is a new one?

Thanks for all your help!

Ali SC3

iTrader: (10)

there are a few online places to have it done for you, or you can pick up a spare ecu in the classifieds, but I wouldn't send it off without looking inside to see if that is the problem. it could be something like a tps if its just hesitation, or even a clogged inector, so in short it could be alot of those things but its not your fuel ecu.

tftimm

Fuel ECU is out. How about the TPS? Is that something that can be checked by DIY?

I'll take out the main ECU and take a look. It should look a little goey from what I read...not clean, correct?

I thought maybe a clogged injector which is why I bought some of the Techron. It isn't nearly as rough of a bad idle or hesitation under acceleration but it is still very noticable.