jkurtz831

Hey guys, looking for a little help here on my 1990 2+0 N/A Z32 coupe 5spd with 85k miles.

Background: I bought the car about a year and a half ago but travel all the time for work so I have been slowly working on fixing her up while driving her when I can (I've driven 3kish miles since I bought it). The previous owner didn't know when the last timing belt had been done and I have wanted to do it for awhile but never found the time. Driving it about a month ago it started running real rough and when I stopped I smelled some burning rubber which I assumed was the timing belt slipping. With winter coming I figured there isn't a better time to get it done than now so i got all the parts and am at the tail end of finishing it (broke the harmonic during disassembly so I'm waiting on a Unorthodox Racing pulley to replace it). When I started the car to drive it in the garage onto a lift it ran fine.

Anyway, I pulled the plugs and found my number 5 spark plug fouled (dry and black). All of my other cylinders look good. I also noticed that the passenger exhaust is depositing a significant amount more carbon on my bumper than the left (the car has what I'm almost certain is a HKS Cat back exhaust). With the car being down and no idea when I will have the parts to get it fixed I was wondering if anyone had any input on what it might be. I can't test the plug or coil pack without starting the car and those are what I'm thinking (hoping) are the problems. I tried uploading pics but it isn't working, any help or input would be great.

Cap

Actually you can test the Injectors and Coil Packs.. Pull the CAS ( The Crank Angle Sensor.. the Funny Drive thing on the Left Cam Pulley ).. and with the Switch on, Spin the Drive for the CAS.. the Coil Packs will fire, and the Injectors will squirt.. Just as if the Car was running..

You have a '90.. check the Spline Drive on the CAS and see if it's chewed.. if it is, you will need to do some surgery to fix it.. Here is a link

http://www.jimwolftechnology.com/wol...SALIGNMENT.pdf


#5 carboned up.. thinking you might have a Bad guide.. after the assembly of the belt goodies, do a compression check, and toss in new plugs.. check them every few thousand miles.. see how they look.. Post the Compression Numbers..

Other stuff to read..
http://www.jimwolftechnology.com/wol...INJFAILURE.pdf

Cap

jkurtz831

Awesome thanks, I just had the CAS out for the timing belt change and the splines looked fine. Do you think I need to take it out and test the TIR on it or should it be pretty clear? Also, I put these plugs (NGK G-Power Platinum tips) in about 3k miles ago, do you have a better recommendation for plugs?

Cap

I'm not up on what plugs are what..

If you had the CAS out, and nothing looks 'Off', then I'd not do the TIR as the Pucks need to come out to get it right.. PITA..

If you read the Injector 'Scare', now you might want to do something about it.. There is a write-up on how to disconectt the +12 from the Injectors, by swapping a wire at the ECU harness ( Under the Passenger Floor ).. look into it..

If you are keeping the Car.. you will want to swap the Injectors to the 93-96 type ( New Style ).. they will last longer.. there is a kit to do it.. Except you need the Injectors..

When you finally get the car on the road.. GET AN ECU.. you will love it.. JWT sells Chipped ECU's.. and on TT net there are a few people that sell them.. It's your ECU that has been 'Chipped' with a New PROM.. There are options, so it's not 'One Chip Fits All'..

MAKE SURE YOU TIGHTEN THE CRANK PULLEY BOLT... if it wiggles it will Fubar your Crank.. The '91 I took care of had a pulley eat the Crank. Likely from a Timing belt Change, where the Bolt was not tightened.. ( NOT ME ).. I ended up JB Welding the Pulley back on the Fubar Crank..

Cap

jkurtz831

Okay, just ran the CAS check (thanks a lot, very cool). All of the coil packs and plugs are firing so it does sound like an injector. I'll do the compression check first, post the numbers and let you know. Thanks again.