Rough Engine

fifty$240 · Feb 9th, 2006, 06:16 PM

I just bought a '91 300zx TT and love it. only 59,000 miles.

Anyway. there are two problems I have. One the Boost guage does not work and sometimes the engin feels as if it has one bad cylinder (not firing). then after a while the engine runs perfect.

Since this is my first Turboed car i do not know what it might be. I am mechanicaly savy, but just don't want to take the engine apart to find the problem. If anyone has any ideas, please share them. Thanks

Outkast · Feb 9th, 2006, 06:28 PM

Check the coils and plugs for spark for the second question and as for the boost gauge I'm at a lose on that one. If it's like an aftermarket one check all the vacuum lines. Cause I have never seen that problem

**Spongerider** · Feb 9th, 2006, 06:55 PM

If it's a intermittent problem it could be a number of thing, loose connection and or fuel injector on it's way out.

Are you using a stock boost gauge or a aftermarket? When you say it does not work does it not move at all?

Big-Reese · Feb 10th, 2006, 10:48 AM

I agree with outkast. But if it is an aftermarket one it could be crap since some times when you buy things new they still dont work. Also you could have wired it wrong. Check the wiring and vacuum lines and all that crap.

fifty$240 · Feb 10th, 2006, 07:07 PM

Thanks all for the input. it is a stock boost guage. When I turn the car on it goes from the Left to center (-14 psi to 0 psi). and then it stays there.

Big-Reese · Feb 10th, 2006, 10:24 PM

The needle doesnt move from there? If thats the case I think Im not for sure but I think its your vaccum lines.

fifty$240 · Feb 11th, 2006, 09:41 PM

I fixed the boost guage. It was a cracked and disconected vacum line to the sensor. I cut the hardend part, spliced in some new hose and hooked it up the sensor. Works great, I Love to see my boost guage work. Lets me know that my turbos are working. I LOVE IT!!!!.

As for the Rough Engine, It is acting normal but once in a blue moon ( usualy after acceleration) it goes back to rough for about a minute and then goes back. I Checked to see if the coil pack connectors were loose and they were ok. Any ideas??

Thanks for the responses so far. I like the input.

Luis

Big-Reese · Feb 12th, 2006, 01:13 PM

it could be alot of things your timing might be off just alittle bit. Your belt could be bad or your pulleys could be bad as well. If it does it after acceleration and then your rpm drop down and it is rough for a min sounds like maybe you pulleys or something.

mgh · Feb 12th, 2006, 07:43 PM

Your rough engine idle sounds like a injector going bad or a bad or corroded connector. These engines are bad at having corroded connectors.

If you know someone that has a ConZult program, this will show engine and sensor fuctions.

If you haven't done the 60K maintenance yet, don't put it off passed 60K. Timing belt break = lunched motor.