I was driving home yesterday, drove over a speed bump and as I stepped on the gas after going over it the car died. Couldn't get it to start back up, I would turn the key and it would fire and then die instantly. I had it towed home and I go out this morning and try to start it it fires up and seems ok so I put it in gear and idle out of the driveway and when I get to the street I step on the gas and it dies again. I have a hard time staring it again and it doesn't want to idle and only stays running if I keep my foot on the gas. I back up down the street back into my driveway, put it in park and it idles fine again. I put it in gear and step on the brakes and give it some gas and no problem, tires start to spin and it's still fine so I idle out of the driveway again and as soon as I hit the street and give it some gas the same thing happens, car dies and won't idle. Get it back into the driveway and it starts idling ok again.

Within the last 500 miles it's had new plugs, cap, rotor, fuel filter, air filter, catalytic converter and o2 sensor. I'm really not sure where to start so any help would be appreciated.

 

Coil.
Close the plug gaps to about 1/3 of what they are now.
If it appears the problem has gone, replace the coil and wires.

 

Tried a new coil, still doing the same thing.

 

Check and/or replace the wires.

 

Plug wires are fine too.

 

Checked the codes and I'm getting code 33 and 34.

 

not sure on the codes but had the same problem with my Bird a year ago. I replaced all kinds of crap on my own like it sounds you have. Had too finally cave in and bring it to the shop, which very seldom happens....
In my case turned out to be the "fuel pump relay". $20.00 part that I could have easily changed on my own. Had I knew that was the problem........ Good luck!

 

Those codes are vacuum pressure at the MAF sensor. When I got those, I had a loose vacuum line. Never heard of one dying because of a vacuum leak though. Usually it is hard to start and idles rough. Ok. I'm absolutely no help.

Steve

 

what about your injectors? when have you had those replaced? also your icm could be going out on you mine did something similar. if you put it in drive and just hold the brake and no gas does it idle under the loaded tranny?

 

Since this car is a 90 it is speed density so codes 33 and 34 are for the MAP sensor. Check the connections at the sensor, especially the vacuum line.

If the connections are good then the MAP sensor could be bad.

 

Also, any vacuum leak will affect the MAP signal, so check all vacuum lines and connections before replcing the sensor.

 

The car idles fine in and out of gear and I can rev the engine in and out of gear while sitting still in my driveway and it's fine but as soon as the car is moving and I step on the gas it dies. It will start to go for a split second and then sputters and dies. I checked the vacuum and get a steady 19" at idle and all connections including the map sensor look good. The injectors all measure between 16 and 17ohm.

 

Maybe try checking fuel pressure kinda sounds like a dieing pump.

 

Try a new coil and then check distributor, It might be 180 degrees out

 

Fuel pressure is steady at 34psi at idle which is the same it's always been. Already tried a new coil and not sure how the distributor could be 180 out since I've never touched it except for changing the cap and rotor a year or so ago.

 

If you can, tape the pressure gauge to the windshield and watch it or have someone else watch it. If the pressure drops right before it dies then it is a fuel delivery problem.

 

No fuel pressure drop when it dies. I put a stethoscope to all the injectors and can hear them all firing too so I really don't think it's a fuel issue.
I was finally able to get it to stall in the driveway but only in gear and not nearly as easily as when it's moving.

 

Ok if its getting airfuel when it dies then go with the flow and check if its losing spark.

Kinda gotta just make a personal flow chart to check one system at a time fuel/timeing/compression spark.

Your local parts store (advance ect) will test your ignition module for free just gotta pull it out of the dizzy if its getting gas and injector pulse kinda sounds like a a module issue but still could be a vats issue.

 

Ca90ss, I was reading your original post and all the rest that we've all posted, and I'm thinking that the whole problem started (acording to what you said) when you hit the speed bump, correct me if I'm wrong. So, if that's the case, you probably hit and/or smashed and/or cracked a fuel line or electrical connection under the car. I would jack the car up and secure it properly then get a nice and bright light and go underneath and check everything real carefully, following the fuel lines, checking the fuel filter for ANY kind of anormality or breakage, crack, or anything that may cause this. And then check all the electrical connections, including the wires conected to the starter, remember that those are main conections to the electrical systems as well. Maybe something is just loose and causes this intermitent problem. Good luck! Keep us posted, we'll help you here!

 

Yeah, it was pretty much as soon as the rear tires came down off the speed bump I hit the gas and that was when the problem started. It wasn't a large bump and I went over it pretty slowly. I did spend quite a while earlier today checking connections under the hood and jacked it up and crawled under it but couldn't find anything but I'll crawl under there again and look around once more just to make sure.

 

As I said before, check all the electrical connections, especially the wires conected to the starter, remember that those are main conections to the electrical systems as well. Maybe something is just loose and causes this intermitent problem.

 

Crawled under the car again and still couldn't find anything out of place. Connections at the starter look good and no crushed fuel lines or anything.

 

Still haven't figured it out. The car has started backfiring through the exhaust now and idling rough. Unplugged the brown and black wire to check the timing and the idle smoothed out and it stopped backfiring. Checked the timing and it was at 6 degrees btdc, turned off the car, cleared the codes from the computer and plugged the wire back in and it started idling rough again and backfiring. I've also replaced the egr valve, plug wires and all the vacuum lines but that was after the backfiring started. Not sure where to go from here.

 

Put a timing light on it for two reasons.
1. Make sure it keeps flashing !! If not, weak or dead spark.
2. Timing. Does it look reasonable ?

in NORMAL running mode. Don't pull the timing jumper.

I'm still thinking spark.
If it was fuel, you would lose pressure. If you have fuel pressure, you have flow.

 

Ok, I'm an idiot and forgot to reconnect one of the air injection hoses when I put everything back together after doing the egr valve so I reconnected that and now the idle is better but it's still backfiring. With the timing jumper connected the timing is steady at about 18-20 degrees btdc at a 1k rpm idle. Not sure of the exact timing since it's a little off the timing tab at that point.

 

Sounds like reasonable timing at 1K, more or less.
Watch the light when it backfires. Still steady ? No misses, or extra flashes ?
A weak coil, or a tracked dist. cap will usually show if you watch the light.
( so do dead plugs, if you go through the trouble of watching the light on every wire )

 

Just a quick thought. I've been having similar issues with my car, seems my Mem/Cal keeps coming loose. Something may have come loose with the ECM or Mem/Cal. I'd try pushing the Mem/Cal onto its pins and/or give the ECM a good tap. It's worked before. Good luck.