Hei. First time here as a member. I have a V6 Firebird ('85 or '87, I always forget, no major difference, I assume). It ran fine until last week. On the next trip I noticed that the engine was very powerless. On a steep, but not extremely steep long hill for example I have gradually lost my speed all the way down to under 30 mph despite flooring it all the way. Engine revved high, transmission in the appropriate gear. The car just didn't produce the power. Also on the way every time there was even the slightest incline, the car could not maintain its speed without significantly more accelerator input, transmission going to lower gear (by 2) and engine revving accordingly. At the same time the fuel consumption has increased greatly. The car used at least 3-4 times the usual amount for the trip. Also, the engine had a harder time to stay cool, probably as it had to work harder for every bump on the road. It didn't overheat, but it was definitely warmer than usual and very hot up the long hill (but without overheating). Also, when starting the car (warm) the engine often idles very low, struggles to keep going, indeed did cut out on a few occasions. It can also happen when going to N and therefore idle. Struggles to keep going. Then either after a while by itself, or be pressing the pedal, the engine recovers, revs up to ca 1500 rpm, stays there for a second or two, and then slowly returns to normal idle.

I really have the feeling that the computer is fighting some imaginary daemons. I am not a mechanic, but I live in Norway (Europe), so there is no mechanic in a 6000 mile radius who has ever seen an old Firebird or have any idea what is what under the hood. There are just so extremely few USA cars around here. ...also for the same reason parts are non-existent here. Everything must be ordered from over the pond, and it takes weeks and the taxes and duty plus shipment always costs several times more than the parts theirselves. ...so I can not exactly grab some parts from the local shop and try testing which solves the problem. I assume that it is either a sensor, or maybe position of distributor/timing, or the computer itself.

You Guys have obviously far more experience with these cars than anyone around here. Anyone came across same set of symptoms? Suggestions as to what I should try, what sensors/parts I should order (best to order all of the possible ones at once, the parts theirselves are very cheap compared to shipping and associated costs, so makes sense to order them all at once, especially as it takes 2-3 weeks for each shipment to arrive).

I am desperate, as I know that no workshop can fix or diagnose it here, but they sure as hell charge Norwegian prices for trying (120 USD/hour). ...so whatever it is, I will have to attempt to at least diagnose it myself.

Thank you so much for your help.

Janos

 

Update: took off the air intake plastic part and looked in behind the butterfly valve. All surfaces I could see are covered in black soot. Don't know if that is normal and/or if that has anything to do with the problem I am experiencing.

 

The soot behind the butterfly is normal as it is from the EGR system.

As for the loss of power, the cat-con may be clogged. Or there may be a fuel or ignition issue.

RBob.

 

Thank you for the answer, RBob. In fact I had a significant blowout in the exhaust, so blockage is definitely not an issue. This is now fixed, making no difference. Since the fuel consumption is also increased, I assumed it can not be a fuel delivery issue (it takes more than enough). Can I still be wrong? Ignition I also considered, all cylinders work (removed wires one at a time) and checked that the distributor is still firmly fixed (could not have turned). How else can be the ignition the problem?

Thank you!

 

"Engine revved high, transmission in the appropriate gear. The car just didn't produce the power. "

Sounds like the engine is running fine?


If your engine is revving but you are not going, I would look at the trans.....could be not enough fluid or its slipping?
if you are revving it to go etc... and the trans isn;t puttign out, then that could explain the higher temps, and increased fuel usage too...


i

 

Thank you, 1989karr for suggestion.

I don't think the issue is with the transmission. The engine doesn't rev like it has no or little load, it revs as the transmission throws it back a gear or two as the engine is unable to maintain speed otherwise. The engine feels and sounds as it is working hard and not just revving with little load. Also this would not explain the unstable idle and tendency to cut out at idle. It definitely feel like an engine problem, in fact it feels like a problem related to the engine controls.

I have ordered a thingy to read out the service port, so once I have it, I will try to see if any values are odd.

Looks like this is not a common problem people knows the answer to.

Thank you once again.
Janos

 

Which reader did you get?


OBD 1 readers are hard to find.


Try disconnecting the MAF and see if it runs better...if it runs better then the MAF is sending a bad signal...totally possible / easy to check.

 

Hi. I bought it on ebay: https://www.ebay.com/itm/11370392875...53.m2749.l2649

According to the description it should work. Will see.

Thank you for the tip! This is very useful, something I can actually check. This is the kind of tip I am after, as I don't know how different sensors behave and how to diagnose them. I must locate the MAF, don't really know which one it is, but I trust I should be able to find it. Can only be around the air intake.

Thank you!

 

Check the fuel pressure regulator, if the diapram ripped it could be sucking gas into the intake causing it to flood out. it would also give you high fuel pressure. The regulator is under the upper intake manifold with a vacuum hose on it if you disconnect it at the intake port with it running and see fuel coming out then you know it is bad.

 

Dear Dana! Thank you very much for a good suggestion. I just have to ask to clarify, is it the vacuum line I need to disconnect (or somehow the entire regulator, if that even makes sense) to check? ...and is the fuel supposed to appear at the vacuum line connection if damaged? Thank you very much.

 

The regulator is hard to get to it is on the fuel rail under the intake. There is a vacuum hose attached to it and it goes into the intake. If you disconnect it and see gas coming out then it is bad. If it is leaking then it is sucking raw gas into the intake and could case alot of the problems you are havving.

 

You are a genius, Dana! No, there is no leak when I remove the vacuum line, however, I discovered, thanks to you, that the rubber L pipe that connects the vacuum line to the regulator has a hole in it! Look like a mouse has chewed on it. I don't know what the symptoms are of a damage like this (ie no vacuum at the regulator), but it is an excellent candidate for troubleshooting. I am going to fix it with a bit of tape and see what happens.

Does anyone know, btw, what the symptoms are of a 'disconnected' fuel pressure regulator? It may be that this is just a coincidence and the hole was there for ages. After all, the car has been ravaged by mice many years ago, not recently. Just curious.

Thank you for the great input!

 

A bad fuel pressure regulator hose shouldn;t give you that many issues.


Did you try the MAF? Just unplug it and see if it runs better...if it does then the MAF is sending icorrect info to the computer.


Easy free test too!

 

The leaking vaccum hose will give the engine full fuel pressure all the time, and a vacumm leak as well. I do agree that the MAF could cause the same type off issues. But a vacuum leak is unmetered air after the MAF it will try to richen the fuel mixture, and with full fuel pressure all the time would also make it run rich.

 

@1989karr and @dana0330 , thank you for your answers. Yes the MAF was suggested earlier, and I tried driving with it disconnected. It made no difference. Also the little hole on that little pipe would surely not result in any significant extra air, I would assume. ...all my vacuum lines are old and crumbly, so if that sort of thing is a major issue, well, maybe I need to somehow replace them all first.

I got now the gaskets for the exhaust leaks, it was suggested that it too could have an impact on the O2 sensor, now this hole is also fixed, will see if after changing the gaskets would improve the situation. ...if not, then I really don't know what else I can try... I so wish I could visit the US with the car and go to a garage where they have seen these types of cars day in day out and have parts for them on the shelves. Life would be so much easier.... Trying to fix an old American in Norway is as hard and as expensive as trying to fix a Mars lander anywhere....

Thank you for your help!

 

It'd be throwing parts at it. but you could start with a good tune up...plugs, filters, fuel filters, wores, cap / rotor.......


a new ignition control module. and coil....... its pretty cheap and if its original, worth a shot!

 

Most of the things are actually pretty new (2 years). Plugs, wires, distributor. First I will see what it does after the exhaust is fixed. What is cheap in the US is definitely not cheap in Norway. I am never able to order everything from the same warehouse, so postage shoots up, and, I have to pay tax and customs on both the part price and the postage. I often pay triple the price of the parts or more before I can get my hands on them. So, unfortunately, I really can't just order everything. ...but, will do, eventually, if nothing else helps.