Putter

My90 L98 was running great. I stopped to eat. When I got back in the car to drive on the highway, it would not fully accelerate. It sounded as though there was a miss in the engine. It would take a long time to build up speed. It would have a rough idle and seemed as though it was going to die when I slowed to a stop. I changed wires, distr. cap, rotor, and rechecked all the plugs. It starts right away, has a rough idle, and when I try to rev up the engine hard, it just shuts down. I have now checked the fuel pressure from the pump. It is 39 lbs & does not drop. The catalytic converter is not plugged up. I guess it is time to check the fuel injectors. Any more ideas?

[Modified by Putter, 8:41 PM 9/29/2002]


[Modified by Putter, 8:42 PM 9/29/2002]


[Modified by Putter, 8:43 PM 9/29/2002]


[Modified by Putter, 4:29 AM 10/9/2002]

Vette9d1

Its the ignition. Is the timing properly set? When mine wasn't (after replacing the cap etc.) it did just like you have said.

madwolf

I'd say converter. Easiest way to check is to cut a hole in the exhaust before the converter and run the car like that. You'll know for sure then.

I've been through this not too long ago.

MrNuke

I vote cat too.
had the EXACT same problems you described about 3 years ago. Had a brick in teh converter from running too rich.. :D

Putter

Sorry guys, I have been out of town. I removed the cat. I can see through it. I am installing an 18" piece of pipe with a downturn on it to see if the car runs any different. I don't want all that hot exhaust blowing directly against the floorpan. Hope the local authority is on coffee break! Could it be that I have a clogged injector? I was conversing with a former 89 owner. He suggested the fuel injector idea. He said that his car just started to run poorly, until he replaced the injectors, then ran like a striped sss ape!

Raistlin

check your timing

65Z01

Don't foreget about the two pre-cats, either of which could become clogged.

c4cruiser

Possibly a clogged fule filter.

Putter

I pulled the fuel pump assembly. I installed a new inlet strainer. The fuel pump is pumping. I pulled the fuel filter off and checked it. It is o.k.. The car starts and idles for a short period of time. Then as I try to rev up the engine, it revs, then just shuts down. It does restart after a few cranks of starter. But, then it does the same sequence, again. I have installed a new computer & rechecked the timing. I am going to check the fuel pressure, as soon as I can get a pressure guage. I am :confused: and :mad . I can't take it to a mechanic because it won't run long enough to get there!

Raistlin

when it rev's up, is it smooth and just dies? or is it sputtering and missing then dies.

Kendall

Mine acted like that when the fuel pump started to die. When you get your pressure gauge it will tell you. On mine it would pump up to pressure but when I shut it off the pressure would drop like a rock instead of holding. A new pump and filter and she was good as new.

Putter

I have edited my original thread to show all of the items that I have either replaced or have tested. Nothing has improved :confused: :confused:

Raistlin

fuel:

you have pressure
you're gonna check the injectors

spark:
ignition module is not on your list
i think you said you checked timing

compression is the last thing to check. have a leak down test done and a compression test.

the computer may also be bad. hooking up a scanner may help find the problem as well.

Putter

I have replaced the ecm (computer) & the ignition module. No difference. I have filled the tank with fresh gas, added a fuel injector cleaner & rechecked the fuel filter. I always buy my gas at Quiktrip. This is a very busy place, so the gas is not in the storage tanks for extended periods of time. I am going to add a can of Heet to disipate the water, if any, in the gas tank. The last thing I will do is check the fuel injectors this weekend. Unless, more than 1 injector is bad, shouldn't the engine run? It starts, rough idles, then when I try to rev up the engine, it starts to rev, sputters, then dies. Starts again, starts to rev, then dies. :confused: :confused: :confused: :confused:

Raistlin

yes, i think the engine would run if only 1 injector was bad.

ok, sounds like you went through everything except compression.
do a compression and leak down test.

i had a '68 nova with a worked over LT-1 350 ('70's style) that i could not find a missfire. finally took the heads off and found a pie shaped piece of one of the exhaust valves broken out.

Putter

I changed the fuel pump. The car starts. When I hold the throttle to say, 2000 rpms, the engine will then drop the rpms down, then back up, then down, then the engine dies. I start it back up, then it does the sequence over. I have ordered a set of injectors. I don't know if there is something I missing, but I think I have replaced everything else!
:confused: :confused: :confused: