Major transmission problems

[rubydist]

519 = PSP circuit open
158 = mafs shorted to power
542 = fuel pump secondary circuit issue
556 = fuel pump primary circuit failure

Those codes do not line up with the symptoms you are describing - in my experience, the engine will not run right with that mafs code, and the only other time I have seen 556 the car would not run at all because the fuel pump would not run. In any event, none of those say anything about a transmission issue.

 

[Ty Paladino]

I believe I caused some of these when I was cleaning injectors, the two fuel pump codes are my main concern, since I can’t get a fuel pump reading at all, the car barely primes. I’m going to drop the tank and clean the whole system back to front.

 

[rubydist]

Now we are more confused, because in your first post you stated that the engine runs well. Now you are saying it barely primes. Which is it?

 

[BaySHO Performance]

Connect a voltmeter to the fuel cutoff switch in the trunk (red button). Turn the ignition on so that the pump primes the rails. If you get voltage at that point, bad pump. If not, bad CCRM.

 

[Ty Paladino]

Well here’s the situation
The car is hard starting without ether. When I get it running, it’ll idle poorly, extremely hesitant to rev. Then it’ll all of a sudden run really good for about 30 seconds and then start running poorly. Always hesitated to rev unless I spray ether in it. It’ll run really good with extra “fuel”. That’s why I believe there’s a fuel issue not a spark issue. It will run on the pump alone but I believe I either have a clog or a bad pump.

Another thing that has come up today is I found a 94 SHO in the wrench a part today with a manual and I’m going to get the trans to swap my car, what all will I need for the mtx swap to a 3.2 atx car?

 

[luigisho]

Transmission, shifter, I would get the wiring harness and computer but others have tuned/worked around it. Maybe center console. I think there are write ups on here and/or the internet on doing this. Also probably have to look at how it mounts and might have to change that a little. How bad is the parts car? It's so much easier to swap a 3.2 into a MTX car. If you have fuel issues check pump, sending unit, pressure regulator, injectors....

 

[Ty Paladino]

The car is near perfect, it’s one of the cleanest I’ve seen, but unfortunately I cannot buy the car, once it enters the yard it cannot be bought whole

I plan to try to get nearly everything from it, and drop it into my car

 

[luigisho]

Check if you need the cv axles also. I don't remember the differences, if any, for atx vs mtx

 

[BaySHO Performance]

what all will I need for the mtx swap to a 3.2 atx car?

To add to Luigi's list of parts needed for an ATX to MTX swap: pedals (3 instead of two), subframe (ATX sits 2" further forward to make room for the transmission), motor mounts and mounting brackets, Y Pipe (yards are prohibited from selling used cats so you will need to get a new one), flywheel, clutch, clutch cable, (which is why the engine needs to be moved back 2" as it won't reach), Center Console for sure.

There's probably other parts I can't think of. This is something I would never try to do. A lot less hassle to junk the ATX and buy an MTX instead.

 

[BaySHO Performance]

Check if you need the cv axles also. I don't remember the differences, if any, for atx vs mtx

Yep, those too. The drivers side may be the same but I doubt it, but the passenger side is vastly different as the transmission reaches almost all the way to the wheel with no intermediate shaft.

 

[luigisho]

There's probably other parts I can't think of. This is something I would never try to do. A lot less hassle to junk the ATX and buy an MTX instead.

I agree I would not either. Not worth the work for me. It's not a quick mix and match. Some people like this kind of thing.

I wonder how the ac lines up once you move the underside around.

 

[RonPorter]

Yeah, it's easier, cheaper, and far less grief to get your current ATX issues corrected. Because if it's about anything but ATX-related, the problems still exist after the MTX swap.

Plus a whole bunch of new issues that crop up after that kind of swap.

 

[BaySHO Performance]

I wonder how the ac lines up once you move the underside around.

Yes, another gotcha. The Accumulator is by the firewall in an ATX, at the front in an MTX.

 

[luigisho]

I think someone still around had done one fo these. rubydist maybe?
yep here's the thread
https://shoforum.com/index.php?threads/atx-mtx-conversion-information.95183/

 

[rubydist]

Yeah, I've done it a couple of times and I would not do it again on a 20+ year old car. It takes new subframe, axles, engine wiring harness, dash wiring harness, computer, new a/c lines, mtx coolant overflow system, mtx cooling fan parts, battery tray/hold down, clutch cable, etc.

It is possible to rewire the atx pcm to work with the mtx so you don't have to change the dash wiring, but if you do that you get all kinds of weird things (like the engine rpm automatically kicking up as you get to about 10 mph as you slow down because it thinks the atx is about to shift down into 1st) that will be happening that I found annoying.

You will definitely spend more than the car is worth to accomplish this.

 

[Ty Paladino]

Thanks a bunch, when I found the car yesterday I knew already that I was going to eventually do it, I plan to grab a lot of the parts off that car and keep them with me until the auto goes south, then I’ll yank it apart and mtx swap it. There’s also a few things weird about that car that I want as well, it has a rear tower brace and what looks like sub frame connectors, plus it’s the cloth insert interior which is near new. I’m going to grab everything and probably try to make the best of both cars.

 

[Ty Paladino]

Also today I will be trailering my car to a new place so I can actually work on it without annoying my coworker. I’m grateful that he let me borrow his garage but I need to be able to get mine going sooner than later.

I just came across another atx for 1k but he said it’s runner driver. Wouldn’t that be the best auto?

 

[RonPorter]

If the ATX works well in the latter car for $1k, pick it up for parts. Although it doesn't seem like it's been determined that the actual ATX is your problem on your current car.

Getting all of the MTX parts off that green one (including subframe) isn't a bad idea, for resale if nothing else. Same with that rear strut tower, sell it to someone who thinks it actually works!

Subframe connectors are nice to have, and do work. But they are always welded on, so getting them won't be an option. You could measure them, to get your own set made.

Does anybody sell the full length subframe connectors anymore? Coupled with AL subframe bushings, they really helped.

 

[Greg Corcoran]

Well here’s the situation
The car is hard starting without ether. <snip> Always hesitated to rev unless I spray ether in it. It’ll run really good with extra “fuel”.

Just a thought - if you have anywhere close to proper pressure at the schrader valve, you're describing a fairly significant vacuum leak rather than a fuel pump or pressure regulator issue. Ether "richens" the mixture enough to overcome the lean condition.
With the little red straw on the spray nozzle (so you can precisely "aim") spray a little at every joint and flexible connector and see where the rpm picks up. Just had to do this 2 weeks ago on a non-SHO after nothing else explained a sudden onset poor running lean condition. I found an intake manifold gasket had failed. Strange but true...

 

[Ty Paladino]

I’ve tried with non chlorinated brake clean and found no such leaks. However I did not do every little thing so I’ll retry that as soon as I’m able to get to the car regularly