RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   URGENT:: 1987 Turbo II Overheating!! (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/urgent-1987-turbo-ii-overheating-868408/)

XenonRT 10-13-09 08:21 AM

URGENT:: 1987 Turbo II Overheating!!
 
I recently blew the engine in my 1987 Turbo II. The previous owner had done some modifications that I was a little leery about: Removed EGR Valve, BAC, and most emission controls. After blowing the engine, I put all the emissions control back on, and replaced the engine block with a rebuild from Atkins Rotary.

However, after putting in the new engine and getting everything working again, it is running hotter than hell! I let it run at idle for around two minutes and the downpipe and catalytic converter glowed red-hot, so I shut it down immediately. I don't want to risk driving it with this problem, for fear of blowing the new engine as well! Especially with the amount of time and money it took to get it running again! (car's been out of commission since April 2009)

If anyone has any ideas as to why the engine might be overheating so badly, please let me know! If you need more information or pictures, I will gladly supply them to help!

lastphaseofthis 10-13-09 09:51 AM

check to see if your original injectors are in there. should end with -1370

barnett87rx7 10-13-09 10:34 AM

you got coolant in there?

TwEaK 10-13-09 11:10 AM

check the timing.. timing could be off making downpipe glow red... if not possibility that cats are clogged up

at what tempature is the motor running? when looking at the temp gauge around where does it sit about 1/4?

TwEaK

eage8 10-13-09 12:19 PM

I would guess that cats are clogged.

XenonRT 10-14-09 10:34 PM


Originally Posted by TwEaK (Post 9559326)
check the timing.. timing could be off making downpipe glow red... if not possibility that cats are clogged up

at what tempature is the motor running? when looking at the temp gauge around where does it sit about 1/4?

TwEaK

I'm not sure, but I'll look into it and get back to you.


Originally Posted by eage8 (Post 9559445)
I would guess that cats are clogged.

Ack! I hope not! Although, if they are, that gives me an excuse to hollow them out. Who needs functionality in emissions controls?


Originally Posted by barnett87rx7 (Post 9559265)
you got coolant in there?

Yes, but I didn't put it there, so it's possible that it isn't a 50/50 mixture. Gotta Check that.


Originally Posted by lastphaseofthis (Post 9559204)
check to see if your original injectors are in there. should end with -1370

Another good thought.. I thought they were original when I put them in during the rebuild, but now I'm not entirely sure... I'll have to go back and double check.


Another related question: Is it possible to tweak ECU settings for the injector pulse-width? If so, could that possibly be my problem? The previous owner used it as a track car, so I don't think it would be terribly far-fetched an idea...

WonkoTheSane 10-15-09 11:44 AM

Cool, Another State College rotary! Not cool, another state college rotary with problems!

I'd start with TwEaK said... I'd lay money on timing or plugged cats, unless your injectors are just shot/clogged...

The only way to really control the injectors is to have the computer chipped, but that's not too common even with a track car, due to the fact that the 1980s ECUs kinda sucked. They're not like the more common ECUs where you could just plug in a re-programmer and flash an upgrade, you have to physically remove and replace the chip with a newly programmed one for these guys. Most people would just get an RTek or sAFC or something to control if they went that way.

How is the idle when it's doing this?

Digi7ech 10-15-09 06:34 PM

Most likely timing related. May be a tooth off.

Re-stab it and check with a timing gun.

XenonRT 11-14-09 01:32 PM

Holy shit, I can't believe it's been almost a month since I posted this problem originally... I've been retarded busy between two jobs and full-time classes, so I haven't had time to update you guys on my progress! Anyway, here goes.

I got a chance to do some work on the car shortly after my second post in here. I took the exhaust off to see if the catalytic converters were clogged, but no such luck. I pulled the Crank Angle Sensor to check the timing on the engine, but that wasn't it either. After a few hours of fooling around with various parts, sensors, and other doohickeys (thats a technical term, there) I was all but three steps away from giving up and calling it a lost cause.

I took some time to sit and think about what the symptoms were, and this is what I came up with:
-The car would run just fine as long as it was moving. However, once it came to a stop and had to idle for any period of time it would overheat and shut down completely.
-After this shut down, it wouldn't restart for a short period of time unless I was lucky enough to be on a hill. (thank god I was testing it out on backroads, eh?)

I thought about what could cause these sypmtoms and about a week ago, I had a breakthrough. I had narrowed it down to one of two things. Either the Mass Air Flow sensor was getting a bad reading at idle, or the ECU was going bad.

As I type this right now, I'm on a break between my two jobs, so I won't be able to jump on it and tell you guys exactly what the problem is, but I have the MAF ready to go on the car. Hopefully that fixes it. If it does or does not, I'll be sure to let you know here.

Thanks to everyone that gave me some insight towards this problem! I hope to have the car back on the roads by Friday!


All times are GMT -5. The time now is 02:23 AM.


© 2024 MH Sub I, LLC dba Internet Brands