MX-3.com

Hey all,
I have a ZE install that's giving me some trouble. It ran fine for a couple of weeks, then it starting choking out under load. It runs a little rough on startup, but accelerates ok under moderate load to about 4k and then chokes out down to an idle. As it gets warmer, the choke point gets lower and lower until the car almost won't accelerate at all. It's possible to baby it up to 50 or 60 on a flat road, but that literally takes a minute or two. A CEL also comes on after about 15 minutes, but if I shut the car off and turn it back off the light goes away for another 15 or so. I had a mechanic read the codes; he said it was the VAF but I tried switching that out and it didn't help and the VAF seems to act normally. I think he was probably guessing, he seemed to be talking out of his butt a lot. Does this problem sound familiar to anyone? Any pointers would be much appreciated.

Looks to me like a vacuum problem. Check your vris/vacuum connections

There are a few different things, some are common, some aren't so common.

The first thing I would do is eliminate the maintenance sort of thing. Do a good fresh tune up if you haven't already. New plugs, new oil, new wires, disty cap and rotor, new pvc valve, new fuel and air filter, check and set your idle, tps, timing, and check the IAC. Then you can check your vacumme lines to make sure they are all correct.

After this is all eliminated then you can really start looking at other things, like doing an HEI mod, or getting a new distributer. It could be a few other possible things, but like i said, check these first because they are easy and relitively cheap to fix or replace.

If you still have the oem black rubber intake hose to your throttle body, check it VERY carefully for the tiniest of cracks. This is a very common cause of hesitation issues. I experienced the exact same symptons, and realized my hose was cracked, changed it and ran perfect.

This also may sound stupid, but when I first got my ride I was washing it constantly, including the engine. One day I started getting those same hesitation issues, and actually got a CEL. Turns out water got into the spark plug wells when I washed the engine, and was shorting the spark to the heads. Ran REALLY bad.

Just some ideas.

Oh yah, the washing thing is a bad idea. It will really mess with your electrical system. Basically you have to tape and bag everyting or wash it with a tooth brush and a hose.

I am having a very similar problem. I thought it was my set-up. ( I am running a ze with je50 vaf and a kl-36 ecu with a millenia IM and TB), but now after reading this I think it is the intake -I will check my air intake b/c I do have a custom made one that is all taped up and air might be getting in. Let me know if changing fixes your problem.

Unmetered air getting into your throttle-body, by by-passing the MAF or VAF

= = = = = =

Car runs like crap, if it runs at all.