FD Seeker

Okay, here's what just happened to my FD. Very strange!

I took the car out after it sat in the garage for a week or two. Did a 5 minute warm up in the garage and started to drive it around the block. After a minute or so I begin accelerating moderately from a stop light... suddenly when the car hits around 4K rpms:
1. the engine light goes on
2. I smell burning electronics (you know the smell, right?)
3. The car loses all power

I pull the car to the side of the road and I notice smoke coming from my glove box area - along with more of that burning electronics smell. I shut the car down, and checked under the hood and found nothing unusual. The car still runs and the smoke stopped and I was able to limp the mile or so home as long as I didn't hit 4K rmp. When in neutral I tried revving the engine a little to confirm - the engine starts bogging at 4K rpm! WTF???

Anyone have an idea what's going on?

FD Seeker

I just started the car up again to see if I could narrow the symptoms a little more...

It appears I CAN get the car to rev slowly past 4K but at ANY RPM if I punch the gas hard the engine bogs.

I also now notice a slight belt slippage squeel when I rev it. This may have been there before, but I really never noticed it (and I probably would).

By the way, ALL guages read normal and no fuses under the hood appear to be blown.

Lost Time

Check the ecu behind the kick panel and see if that's where the smell is coming from. If it is, try to narrow down which connector. We'll go from there.

FD Seeker

The ECU is behind the passenger side kick panel?

spooledUP7

Glove box? Yep, bad Flux Capacitor.

Have you checked the engine light code yet?

GsrSol

Yup, do you know if the previous owner did the "fan mod"?

FD Seeker

OK, I found the site describing how to check the engine light code, and I'll try first thing tomorrow:
http://www.jayspec7.com/errorcodes.html

I seriously doubt the fan mod was done (but not 100% sure).

Seriously guys: What electronics are behind the glove box area that could burn out?????

downwinddave

1991 vert New to me. I also have the 3800 bog/ intermittent death. I have checked the ground to the engine, run one tank with injector cleaner, and checked the engine code - only one:17 (may be O2 sen-which looks new) Reseting code tomorrow AM. Next checking ground to ECU. If I go over a speed bump - runs fine. Something is loose!

skunks

go to
http://www.ScuderiaCiriani.com/rx7/engine_codes.html

to check the engine codes.

and yes the ecu is behind the passenger kick panel, the only other thing inback of the glovebox is the ac blower i think.

anykinda burning smell is bad, don't drive your car untill you fine what is smoking unless you want one dead car!

FD Seeker

While I don't believe my car has the "fan mod", please explain how this might affect the situation.

FD Seeker

OK, just checked the engine light codes... here's what I got:
26 - Metering Oil Pump Stepping Motor open or short circuit
27 - Metering Oil Pump Sensor open or short circuit or MOP sticking

What does this mean?

Lost Time

Have you checked the ecu yet?

Hyperite

Yeah, i dunno if i'd trust anything the ECU engine codes are telling you if the thing is catching fire. Smoke out the glove box can be from the ECU, smoke goes up, glovebox is above ECU. Take it out and look for scortch marks. Hell, check the OMP too.

~Tom

GsrSol

The fan mod consists of a few wires, switch, and sometimes a relay next to the ecu. I was thinking maybe a bad install on that.

maxpesce

The center speaker amp is also next to the glovebox in the center consol - not that frying the amp would affect the engine - the 4k bog sounds like the ecu has gone into a limp-home mode - a lot of the wiring runs behind the glovebox you may have a short in the main ecu harness or your ECU may have self destructed, The FAN MOD involves splicing into some wires at the ecu connector, a potential source for short circuits

A Bad OMP/ompSensor will cause the ecu to go into Limp Mode

FD Seeker

Well, I removed the kick plat to look at the ECU... that is definitely where the burning electronics smell is coming from. After removing the ECU cover all I can really see is the back of the circuit board - nothing looks burnt or unusual. It doesn't look easy to remove the entire unit for further inspection. Suggestions?

Lost Time

To be perfectly honest with you, the easy thing to say here, would be to just get a new computer. Unfortunately, unless you find out why this one fried, you may end up doing the same thing to your new one. And since I don't know all that much about wiring I'm going to let someone else in here. Just don't go throwing another ecu in there before finding the problem.

FD Seeker

I reset the engine light by disconnecting the battery. After a couple of minutes the light came back on. They check out the same at 26 & 27.

I called TriPoint for some insight. They never really heard of anything like this happening to the ECU. Obviously they can't render a good opinion without looking at the car ($150). They said based on the codes that there could be a problem with the Oil Metering Pump. They said if that needs to be replaced: $2200. If it's the computer... around $1000. Both??????

Anyone have any experience with the OMP?
How much are they?
Can you get them rebuilt?
How difficult to install?

Lost Time

If it does come down to replacing the computer, which if you smell burned wiring it probably will, you can either buy a used reprogrammed unit ($400ish) or a stand-alone ($1000ish). You would NOT buy another stock ecu. As far as the metering pump..... I don't think a bad OMP would fry your ecu. Worse case let's say it did. Others have just ditched their OMP and premix their gas. That'll save you the OMP money. I do recommend at this point you do take it to a pro for troubleshooting.

Rx7aholic

iTrader: (22)

Or your engine ecu harness that goes to the engine is creating a slight short or the omp harness. I find very hard to believe that the omp is dead. But id it's u can always grab one for $50-$150 from the partstrader.Don't forget that your ecu harness run next to the downpipe and into the engine. Also I don't if u r mechanic inclined if u r great u can replace your omp but u need to removed the turbos in order to get to it. If u live in NJ I would be glad to help u out.

maxpesce

From your posts it sounds like you have a FSM - follow the procedures for checking the harness connectors and circuts - eliminate any wiring problems first before trying to plug in a new ECU - you should be able to find a good used ecu for >$300 or get a PFC, JUST MAKE SURE YOUR HARNESS is GOOD FIRST! An OMP replacement is expen$ive because its a Bitch to get off the motor - its down under the airpump

FD Seeker

Tripoint told me that aftermarket computers aren't good at controlling a lot of stuff that the stock ECU takes care of. Therefore, a computer upgrade is usually in addition to the stock ECU (my car is totally stock). Therefore, I would probably want to keep (fix) my stock ECU.

Anyone care to comment on this?

rynberg

Well a reprogrammed or add-on ecu (M2, Pettit, etc) would obviously control everything correctly.

A stand-alone ecu like PowerFC controls everything. The Haltec doesn't control the OMP (prob other things as well) so you have to pre-mix. I don't know about other ecus.

All in all, their point is not very valid.

GsrSol

The ECU is very easy to take out (3 bolts). DO NOT pay someone else to swap it, it would be a huge waste of money.

Also when ECU's go bad, they sometimes tend to throw codes that doesn't mean anything is wrong. Only replace the OMP if you fix the current problem and with a different ecu you still get the codes.

djantlive

I would just get a used stock ECU but buy it from someone trust worthy. It's hard to tell whether they are busted or not so becareful. I would get it from someone local, swap it in and pay for it if the car runs okay.

The reprogrammed ecu are not designed for your stock setup so I don't recommend it unless you can get one w/ stock programming.