By on January 23, 2012

 

C.V. writes:

I am a mechanical engineering student looking to learn how to work on cars.

My friend has given me the opportunity to take his 1988 Mazda B2200 extra-cab 5-speed. When I drove it, I saw why. The catalytic converter has broken off, and apparently pieces of it are in the exhaust. Would it be possible to just replace the catalytic converter, or should I replace the whole exhaust?

Also while driving it, there is a weird problem. About 10 or so minutes after startup and driving, it starts bucking back and forth as if I was engaging and disengaging the clutch. Any idea as to why that is happening? Theoretically the truck could drive even with this problem, but I don’t think it’s safe or good for the truck. What should I do?

Sajeev answers:

It wasn’t long ago that I was an mechanical engineering student looking to work on cars.  Hell, it’s way more fun than a semester of Thermodynamics, Solid and Fluid Mechanics! So what’s my advice?  Join the Society of Automotive Engineers (SAE) as a student and join the local chapter in your college.  The SAE chapter at the University of Texas changed my life, in a good way. And if you don’t have a chapter?  MAKE ONE!

Oh wait…you wanted advice on the truck, not your career. My bad.

The first problem is pretty easy, replace the convertor. Or not: eventually the loose bits of honeycomb inside will stop playing Super Breakout with itself, exit stage left, and it still might pass an emissions test.  If not, any exhaust shop can slap in a new one, and I just Googled one for $270 that’s a direct replacement.  I am sure you college kids use Google all the time, why not for a sweet little truck?

The second one is usually a combination of a poor gear change technique and a lack of fuel.  Or maybe too much fuel.  Does it buck less if you give it more gas and take more time to let out the clutch?  Problem solved. If not, I’d recommend rebuilding the carb, seafoaming the motor (at your own risk, see YouTube for reasons why), and testing the fuel pressure.  Actually not in that order: start with fuel pressure, then maybe learn how to work on a carb.

Or convert it to a later-model EFI setup! Or even better, LS1-FTW!!! You are an engineer for a reason!

Send your queries to sajeev@thetruthaboutcars.com . Spare no details and ask for a speedy resolution if you’re in a hurry.

Get the latest TTAC e-Newsletter!

12 Comments on “Piston Slap: Playing Super Breakout by Itself?...”


  • avatar

    Seafoam…

  • avatar
    tedward

    Bucking coming on and off throttle while in gear? The drivetrain could be moving around inside the car if you have worn or broken mounts. Could be flywheel related also.

    Your shifting isn’t causing it directly, but someone’s harsh shifting probably contributed to the wear sometime in the past. On the other hand, this truck is old and all that stuff needs replacing anyway.

  • avatar
    Feds

    Sorry Sajeev, the proper swap for a B2200 is the F2T 12 valve turbo our of a probe/mx6/whathaveyou. This engine swap offers the right combination of deceptive difficulty (It’s the same block, how hard could it be?), incredible costs (a new turbo costs WHAT!!!???), and lack of results (All that, and it’s only putting 180 hp to the wheels!?!?! I should have done an LS-x).

    If you do the right thing right away, how would anyone learn anything?

    • 0 avatar
      smokingclutch

      The most interesting swaps for these is a 13B. Mazda engineered the 86-92 trucks to take a rotary engine. The Frame rails are set wider apart than the earlier trucks, which makes the swap easier than on the earlier trucks. (The REPU had wider set frame rails as well.)

      A 12A drops right in, but is a bit low on power for these trucks. A 13B will also go right in, as long as you make sure to procure a front cover from an 84-85 RX-7 GSL-SE for the correct motor mount position. The manual transmission (Type-M or Type-R, I forget which) is shared with the RX-7 – just need to swap the bell housing. You can keep your driveshaft, and if you want an LSD, the pumpkin out of a GSL-SE will supply it – just keep the truck axles as you’ll need them to keep the track correct and the 6-lug pattern.

      Since these trucks came with a carb, you can easily stay carb with the 13B which will make the whole project much easier. With the right bits, you can manage 160-180 hp without porting the motor, which isn’t earth shattering but is almost twice what the truck came with, and is just about right for a truck that weighs 2500-2800 lbs, depending on configuration and options. The 13B is lighter than the F2 engine it came with.

      FWIW, the F2T is actually a bit harder to fit since the firewall on the truck is where the distributor wants to be. If you want to stay with that engine series, an FE3 out of a Kia Sportage (yes, really) is a good starting point. I you can get a genuine Mazda FE3, even better, as they have forged internals and are good for 170hp naturally aspirated, but they were never sold in the US and not particularly common engines in any case.

      The LSx gives the best bang-for-buck, to be sure, but the 13B swap is about as painless as it will get.

      Back to your original question… If the truck is in ok shape, a new cat is a no-brainer. $300 parts and labor should do it. These have Nikki electronic carbs that are notoriously difficult to rebuild. If you have a carb issue, I would go with one of the Weber downdraft kits they make for these 32/36DGEV or something like that.

      I had one of these with the Weber, a header and a glass pack, and it sounded remarkably like an old British sports car. Very rorty. Those mods woke it up but it was still fast by no means. These can be made to handle pretty well, too. The tin worm ate mine, like most of them. I would love to find a nice, low mileage, rust free example from out west to do the 13B swap!

  • avatar
    GS650G

    Oxygen sensor is most likely shot. You can check it with a voltmeter, it should switch from 5 volts down to .45 when running, or you can retrieve codes from the computer.
    Black plugs and poor mileage, along with black exhaust are a giveaway.

    The converter is a common problem with Fords from that era, if you don’t have emissions you can try a test pipe in it’s place.

  • avatar
    texan01

    If I remember correctly from my brother in law’s 87 B2000, the cat is directly bolted to the exhaust manifold. Not difficult to change really.

    All I remember of that truck was it was fun to drive, slow as molasses, had the weirdest emission controls and sported a 2 or 3 barrel carb. The 2200 was a bigger version of that 2.0. He kept it till the clutch wore out and traded it for a 95 C1500 in 99.

    The 2600i was where it got interesting and everything swapped sides.

  • avatar
    wstarvingteacher

    Can’t say about your state but in Texas you become exempt from emissions testing next year. My guess is that you can’t pass. Have had to read some about it recently and the cat could be broken up by periods of excess fuel in the exhaust. They only process so much and how much time that takes depends on the engine and it’s tune. It can go fast. Replacing it is a good idea if you have checked for underlying problems. If you have excessive hydrocarbons I think it’s throwing good money after bad.

    If you basically have good engine internals you have found something you can consider a keeper. It’s probably cheaper to keep than to buy new if you know a good independent mechanic. If you don’t – you need to. My 87 Nissan now sets in a back pasture with a frozen engine. It had over 300k on the odometer before it decided to croak.

    For a college student you have one of two things here. It is either an economical answer to long term transportation while you are becoming a well comphensated member of society, or, it’s a money pit. Depends on the truck.

  • avatar
    greaseyknight

    The bucking almost sounds like the exhaust pipe/muffler is clogged with bits of the catalytic converter, and is creating alot of back pressure. We had a Nissan Quest that did something similar when hot, it got worse to the point where it wouldn’t move. Took the exhaust apart and cleaned all the pieces out.

    • 0 avatar
      fincar1

      +1; same thing happened with my 1999 Accord when it had 150k or so miles on it. It had given a check engine light that I ignored because of a year’s worth of spurious indications before that.

  • avatar
    millmech

    I had a Nissan truck, 1983, with a carb; anyway, that + a number of other 80s vehicles would “jerk off” if trying to coast with ANY amount of throttle. The only way to coast in gear smoothly was to take foot OFF the throttle.
    Having said that, something made the converter come apart; better find out what.


Back to TopLeave a Reply

You must be logged in to post a comment.

Subscribe without commenting

Recent Comments

  • Re: Last First-Gen Volvo XC90 Rolls Out Of Torslanda

    Chicago Dude - What exactly are you scared about with the new engines? Volvo has been boosting engines since just about the beginning of time. The...
  • Re: Toyota May Kill V6 Camry

    28-Cars-Later - Because that sort of behavior p*sses off customers, GM has been guilty of such stuff for decades. So say Toyota does this and disenfranchises the 15% or so of the...
  • Re: Toyota May Kill V6 Camry

    bomberpete - The V-6 is a great engine and I doubt the Highlander or Avalon will lose it. Toyota’s strategy is to make the cheapskates pay for the privilege, whether in...
  • Re: Junkyard Find: 1986 Buick Somerset

    ChiefPontiaxe - The C5 Corvette also spells it this way
  • Re: Toyota May Kill V6 Camry

    Astigmatism - @jc130 This wins. EVERYTHING.
  • Re: Junkyard Find: 1986 Buick Somerset

    ChiefPontiaxe - The Regal Somerset Edition started out in 1980, not 1985. My Cousin Stanley had one in two-tone navy and manila (both interior and exterior were...
  • Re: EPA Mandates Real-World Testing For All Automakers

    Land Ark - Well, I certain am not calling for the abolishment of EPA (they don’t refer to themselves as “The”) since Mrs. Land Ark...
  • Re: Toyota May Kill V6 Camry

    jc130 - People are “Fans of the Toyota Camry” in the same way they are fans of stainless steel refrigerators.
  • Re: Toyota May Kill V6 Camry

    Frantz - On of many reasons leases are on the upswing for new cars is consumer concern for all the new technologies out in cars. Turbos have been used on long life vehicles for...
  • Re: Toyota May Kill V6 Camry

    VoGo - 28-cars-later, I hear you, but why should Toyota offer you a V6 Camry for 27K, when they can force you into a 37K EZ or a 32K Avalon? If the rest of the market is...

New Car Research

Get a Free Dealer Quote

Staff

  • Authors

  • Brendan McAleer, Canada
  • Marcelo De Vasconcellos, Brazil
  • Matthias Gasnier, Australia
  • Tycho de Feyter, China
  • W. Christian 'Mental' Ward, Abu Dhabi
  • Mark Stevenson, Canada
  • Faisal Ali Khan, India