Question to help solve a minor problem

2.5mazda · Post by **2.5mazda** » May 25th, 2006, 7:16 pm

Sometimes on my ZE when I start it up it wants to idle rough and die inless I tap the gas. After a minute of driving it is normal. Durring that minute though it bogs a little, feels choked up and then goes away.... It only happens every couple starts. Any ideas?
Are the DE injectors and fuel rails the same as the ZE? I doubr that is the problem (I used DE ones, but also have ZE's)? Anyone else have this problem ever?

hgallegos915 · Post by **hgallegos915** » May 25th, 2006, 7:57 pm

nah check your vacuums and check the tps and throttle body. Iac usually makes it do that.

jschrauwen · Post by **jschrauwen** » May 26th, 2006, 2:16 pm

Cold engine starts are a function of the ISC Solenoid located at the bottom of the TB. It senses the coolant temp residing in the bottom of the TB. That is however, if you haven't disconnected the coolant lines to the TB in the first place. The ISC will sense the coolant temp and will generat the aplicable signal to the ECU to bump up the idle. As the temp in the TB increases the ISC readings will change and therefore send new signals to the ECU to cut bqack on fuel and idel speed settings. That's why on cold morning engine starts, the engine will go to approximately 1,400 to 1,600 rpms and then from there gradually drop down to a normal 700rpm. As Hector mentioned, a confirmation of all vaccum lines would be first. This will also include the main intake tract tubing. There can be absolutely no cracks or fatigue on any part of that intake tubing between the VAF anf the TB. A good cleaning and complete setting of the TB may also be necessary, and I've posted a handy "How to" in the FAQ section for that. After you've tackled all of that, then we can revisit this original problem and see if it has migrated to something new or has been solved. Post back your findings so as to help the next guy please.

Post by **Custommx3** » May 26th, 2006, 2:28 pm

Dont forget also..
if you coolant temp sensor is bad, the IAC will not get a proper reading, so check your codes.

2.5mazda · Post by **2.5mazda** » May 26th, 2006, 6:37 pm

I have had a check engine light on since I owned it, now, 2nd engine and it still has one. It's weird, comes on, goes off, no real rthyme or reason to it. Coolent lines were NOT bypassed on this swap, and I have tryed adjusting the IAC.... It isnt on cold starts, I can shut it off and come back half hour later and its choppy for the first minute or so, seems sluggish and has a bit of a miss, (or so it sounds) then it goes away and the car runs fine.