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A little background info first...My father recently purchased a 93 R1 with 39k miles on it. The car has only been driven about 600 miles since 2008 . The car does start right up and can be driven, however, it does not appear to be making much (if any) boost. The wife of the original owner said she did take the car to the Mazda dealer and they said it needed new turbochargers and gave her an estimate of $4,000.
So far we have drained the old fuel, and put in fresh 93 octane with premix as well as a new fuel filter.
Today a fellow FD owner and myself pulled the UIM off, to do the vacuum hose job. So far I have found the following:
The clamps on both Y pipe connectors were extremely loose...you could have probably taken them off by hand.
The blue plug in the center of the picture was not attached to anything. I do not have all items removed to complete the vacuum hose job, but at this point, I have not been able to locate the other end of this connector.
The vacuum hoses appear to be original and actually seem to be in pretty decent shape. I have yet to find any that are brittle.
Nice car Matt.
*The rubber 'Y' pipe to cross-over coupler is exposed to a lot of heat and fails eventually. There was a later re-design that eliminated it...and flowed a little better. Replace the coupler with a good silicone version...or look for the latter 'Efini' 'Y' pipe.
*Don't try to re-use the upper intake to lower intake manifold gasket. Get a new one. Early production 93's actually had a cheezy-thin gasket which was also replaced by a much better redesign. So don't be surprised if it looks different. A vacuum leak there is a PITA.
*If your car still has the pre-cat, get it off and replace it with a quality downpipe as soon as possible. They had some reputation for collapsing and taking out the main cat. And it's a hellish source of heat that bakes all those under-hood plastics, solenoids and hoses.
*Don't be like the previous owner's wife and take it to a dealership...even if you can afford it. Most technicians have never seen one of these cars, let alone worked on one. Find a reputable rotary specialty shop near you.
*Don't be like the previous owner's wife and take it to a dealership...even if you can afford it. Most technicians have never seen one of these cars, let alone worked on one. Find a reputable rotary specialty shop near you.
Thanks! My current plan is to replace the vacuum hoses with a high quality silicone and also test all solenoids while I have it apart. Then install new plugs, wires, and belts followed by a re-assemble using new gaskets and Samco couplers on the Y pipe. The car is completely stock, so once I get it boosting properly I planned to do the downpipe and AST.
^Nice plan.
It sounds like you know what you're doing. But at the risk of insulting you, be careful not to over-torque the fasteners on the UIM during re-assembly.
Thank you, that is a good reminder. I still need to find the torque spec and sequence for those bolts. I had a little more time to work on it tonight and I have found a few more surprises. It looks like some rodents were living in the air box, and as a result about half of the filter material was chewed away. I took the air control valve off and it is 100% packed tightly with what I believe is the filter material. Next I plan to remove and inspect the intercooler and also try to inspect the turbos,then install silicone hoses and test solenoids.
Welcome an good luck. Keep the twins alive you'll be very happy and if you decide to go single turbo in the future at least you had the twins.
I just got done with the vac job on my car. Since you're there replace the fuel pulsation damper, remove your injectors and send them t RC engineering to get cleaned, tap your water pump housing for a temp gauge. I personally also cleaned up and fixed the wiring harness, I had it completely removed. I also found that the easiest way to route a vacuum hose for the boost gauge is if you run it through the shifter hole on the bottom and route it along the transmission wiring harness. That's if you're mounting a gauge on the DIN pocket
... tap your water pump housing for a temp gauge. ...
I absolutely agree that he needs an aftermarket temp gauge if he doesn't already have one. The stock gauge isn't linear and is worse than worthless.
But IMO there's a better alternative than taping the WP housing. On a stock car there's a MUCH easier place to source accurate temps and you get readings immediately...no waiting for the t-stat to open. ---> https://www.rx7club.com/3rd-generati...d-idea-392910/
See post #37 for list of the fittings for <$10 from any hardware store.
A picture of mine from years ago when I still had the accelerated warm-up system (AWS) in place.... disconnect AWS line from back of throttle-body, insert one hose barb, add a short section of hose to the other barb and re-connect to the t-body. Done. And unlike the drilling and tapping method, it's completely reversible.
Even after a rebuild some years back when AWS and all the other emissions were deleted, I still use the same line for the sensor...just looped it:
I absolutely agree that he needs an aftermarket temp gauge if he doesn't already have one. The stock gauge isn't linear and is worse than worthless.
But IMO there's a better alternative than taping the WP housing. On a stock car there's a MUCH easier place to source accurate temps and you get readings immediately...no waiting for the t-stat to open. ---> https://www.rx7club.com/3rd-generati...d-idea-392910/
See post #37 for list of the fittings for <$10 from any hardware store.
A picture of mine from years ago when I still had the accelerated warm-up system (AWS) in place.... disconnect AWS line from back of throttle-body, insert one hose barb, add a short section of hose to the other barb and re-connect to the t-body. Done. And unlike the drilling and tapping method, it's completely reversible.
Even after a rebuild some years back when AWS and all the other emissions were deleted, I still use the same line for the sensor...just looped it:
I actually taped the water pump housing on the back. The readings are very accurate and fast acting. I agree that the thermostat housing isn't the best spot
Thanks for all of the info and link to the FSM...it has already been extremely helpful! I tested all of the solenoids and actuators this past weekend and I did have one bad rack solenoid. I am now in the process of upgrading all hoses to silicone and cleaning all of the stock parts before they get reinstalled. The acv was packed full of filter material and took about 2 hours to get cleaned out completely. I'm hoping that the plugged acv, bad rack solenoid, and loose hose clamps on the couplers were playing a role in the boost issue...fingers crossed!
I got it all back together last night and fired it up. It instantly starts surging with the idle constantly bouncing between 1k and 2k rpms like it was doing previously. I have not road tested the car yet, to see if it is boosting properly or not. I was hoping that that the completely plugged ACV and bad rack solenoid had something to do with the idle surging, but I guess not.
Tonight I plan to adjust the TPS, and then I'm not sure where to go next if that does not resolve the issue.
Given everything that you did, my first suspect is a vacuum leak. Does the loping idle change once the car warms up?
I let the car run for almost 10 minutes last night and the idle never changed. Before I did anything to the car, it idled the same, but usually after a few minutes of running. I thought it was a vacuum leak as well, which is why I dug into the hoses. I did not find any issues with any of the stock hoses, and I replaced them all anyway and triple checked them.
I don't see it being the issue, but you might pull the idle air control valve and clean it. They will carbon up over time. It's easy to do, a couple 10mm nuts and the connector IIRC. I just use some brake parts cleaner.
I was thinking of trying that...I just had the car running and disconnected the idle air control valve and it made no difference at all. I also turned the lights on and the idle would then raise to around 2500 and fluctuate from 2400-2600...much tighter than its usual 1000-2000 range.
Saturday morning update...I finally took it for a small (10 mile) road test this morning. This is where I can finally see improvement...before the car did not seem to have much power at all, and it would basically hit a wall at 4500-5k where it simply seemed like it did not want to go any higher. Now it seems to be making power and will rev up freely. I have yet to install a boost gauge, but the car does appear to be making boost. While driving the car feels good and revs smoothly, it only seems to have the issues at idle. Even after my 10 mile drive the car will constantly rev between 1k-2k rpm at idle. I feel pretty confident that once I get that issue corrected, it will be a properly running FD.
I'm going to go put it on ramps, and replace the last few hoses that were not visible from the top of the motor.
I don't see it being the issue, but you might pull the idle air control valve and clean it. They will carbon up over time. It's easy to do, a couple 10mm nuts and the connector IIRC. I just use some brake parts cleaner.
I just pulled the idle air control valve off and found that the valve is not fully closed because there were 2 items in the way keeping it open...one looked like a seed, and not sure of the other one. The items have been removed, but the valve did not close as I was expecting. When 12v is applied it clicks and moves slightly, but seems to go back to its original position, which is partly open. Can anyone confirm that the valve should be closed when off?
05-23-15, 04:01 PM
Can anyone ID this connector? (FD)
