So, I've got this '92 Prizm... and I hate it. It's your normal 4A-FE / 3spd sedan, 92K on the clock.
I got it from an old man who parked it in the driveway when his elderly wife died... seven years ago, so it's a little odd. The problem with it is that it's unsafe slow. It's doesn't take off from a stop, and at times you can only get to 20mph, it doesn't have the power to go faster. It does have more power the higher it revs.
Things I've replaced:
Head Gasket (showing ~155psi now)
Fan Fuse
Fuel Pump
Fuel Strainer
Fuel Filter (twice, including multiple backwashes on the first one)
Air Filter
Things I've done:
Changed oil (10w-30)
Cleaned fuel tank (muriatic acid)
Cleaned and gapped plugs (0.40")
Checked wires (very good)
Checked cap and rotor (clean)
The car seems to bog very badly, and if you can get it to second gear it seems to like light throttle more than heavy throttle. This screams fuel system problems to me, but I can't find a place locally to buy an Actron banjo bolt adapter for my pressure guage so... kinda guessing.
The kicker is I cleaned the fuel tank today, and it ran great, for about two blocks. It had good power and I'm sure that with careful planning and situational awareness it'd be a great traffic warrior... which is what I want it for. It just won't go.
What can I test to figure this out? Oh, and I have the '90 FSM from when I had a '90 in high school.
EDIT: thinking about it more, the thing that changed to slow it this time was putting five gallons of gas in it. And no, it's not bad gas, I only buy from one station and none of my other cars randomly lose power.
Last edited by Rabbitbunny; 07-30-2011 at 06:14 PM.
Reason: I'm retarded.
It kinda sounds like the timing is off. I'm not sure which way, maybe to advanced since you don't have any low end but good high end. Perhaps the timing belt if off by one or more teeth? I assume that you had to take it off when doing the head gasket as it would be impossible to do without. Check the ignition timing also, that could be off as well.
Good luck.
In addition to timing check for vac leaks. In particular vac line from MAP sensor that is mounted on firewall and runs to intake manifold. Might want to check coil and pickup coil in distributor to see if in specs. Possibly someone makes an adapter you could purchase to allow you to hook up fuel gauge. Would be good to see if your fuel pump is putting out proper pressure. Maybe the strainer on the pump has some crud on it hampering flow. That seven year sit developed some serious gum/varnish buildup. Another thought if your engine has an egr valve it may be sticking or not metering properly causing it to bog. My 90 doesn't have one but your 92 may. Have you replaced thermostat? If not the engine may not be reaching operating temp causing computer to asume it's in cold operating mode. If your bog occurs only with cold engine check the idle air bleed. It elevates idle speed with engine cold to prevent bogging . Remove rubber air intake and look at square shaped opening on bottom of throttle body. Spray it with carb cleaner. When you put finger over hole should feel vac. When engine warm shouldn't feel vac at the port.I have same engine in a 90. It's not a nosebleed special but seems pretty peppy . Can easily get up to speed on highway.No lag at all when accelerating.
The mechanical and ignition timing are perfectly spot on, I just checked both.
Vacuum looks good and passes the carb cleaner test, it didn't once idle up the whole time I sprayed around it.
I'm not seeing any specs for testing the MAP sensor, but it's there and has good hosing.
My pickup coil doesn't match my FSM, the dist has a 6 wire and 2 wire connector. The book tells me to measure a 4 wire connector.
My ignition coil tests good hot and cold.
This fuel gauge is becoming... problematic. Pinching the fuel return hose from the FPR to the tank doesn't improve performance, so I know that's not dumping fuel back into the tank.
The EGR is working great, it passes the tests with ease.
The thermo is a new 195*F unit, with two 5/32" bleed holes.
And while I was at it I cleaned the idle air bleed.
So, Seems like low pressure from the pump due to the pump or a blocked strainer (both new). Good thing it only takes me about 45min to drop and strip the tank.
My pickup coil doesn't match my FSM, the dist has a 6 wire and 2 wire connector. The book tells me to measure a 4 wire connector.
Look at that picture again. The diagram is pointing to spaces not pins. I believe you are looking at the same picture I am looking at. I got confused before also.
Look at that picture again. The diagram is pointing to spaces not pins. I believe you are looking at the same picture I am looking at. I got confused before also.
6D4-5, Figure 4?
Quote:
Originally Posted by RogueMoog
Could the fuel injectors need a cleaning?
I don't know, I've got them on my cleaning bench running kerosine through them with the ultrasonic right now.
Interesting clue, It did it to me quite badly today. It stalled, and when I restarted it ran at about 50% of normal power, quite well considering.
Here's what I'm thinking...
That tank is quite hard to see into, so how much crap is really left in there? Say there's something in there that plugs the pre-filter/screen and turning off the pump let some of the debris fall... therefore allowing power. Lean engine do get hot, and this is one hot headed little car.
I'm not quite sure of that because I've never had to deal with a car that sat before, I normally only work on cars that run, or just died.
Have you tried disconnecting fuel line at front and at the back and blowing out the lines with an air compressor? Another thought is the ignitor (inside distributor) and a bad distributor rotor (could have a small crack not visible to eye).
That tank is quite hard to see into, so how much crap is really left in there?
You can see into the tank quite easily if you pull the rear seat cushion, and take the screws out of where the sending unit mounts to the top of the tank and pull the sending unit out.
I'll try to remember to look when I get home at the diagram.
The thing that's bothering me is that the engine runs fine at the higher revs right? So most of those problems would affect the range of engine operation, which it doesn't? I dunno. You know I've been having a similar problem with my 4AFE, when warm and at idle, it idles rough, but off idle everything is fine. I haven't been able to figure it out yet... Oh well, I was just hoping to replace the engine before having to fix it.
Have you tried disconnecting fuel line at front and at the back and blowing out the lines with an air compressor? Another thought is the ignitor (inside distributor) and a bad distributor rotor (could have a small crack not visible to eye).
Yup, I always blow out the lines when I replace a pump. I'll check those two.
Quote:
Originally Posted by blb
You can see into the tank quite easily if you pull the rear seat cushion, and take the screws out of where the sending unit mounts to the top of the tank and pull the sending unit out.
Well, yeah, but the problem is that old gas makes this... I don't even know how to describe it. It's like mud with a thick honey covering, allowed to bake in the sun. I bet it's not only on the sides, it must be on the top too. Dumb hands are too big to get in there.
Quote:
Originally Posted by SuperRA
The thing that's bothering me is that the engine runs fine at the higher revs right? So most of those problems would affect the range of engine operation, which it doesn't? I dunno. You know I've been having a similar problem with my 4AFE, when warm and at idle, it idles rough, but off idle everything is fine. I haven't been able to figure it out yet... Oh well, I was just hoping to replace the engine before having to fix it.
Well, It runs fine at high revs... when it runs fine. Sometimes restart it, sometimes wait a few hours... sometimes a day. One day it ran perfect for over 80 miles.
When it doesn't run fine, it doesn't do high revs. Assuming the redline is at 8Krpm or so, it doesn't go over 2Krpm.
Well, It runs fine at high revs... when it runs fine. Sometimes restart it, sometimes wait a few hours... sometimes a day. One day it ran perfect for over 80 miles.
When it doesn't run fine, it doesn't do high revs. Assuming the redline is at 8Krpm or so, it doesn't go over 2Krpm.
OOooh ok, I misunderstood your first post. So this is an intermittent problem correct? Hmmm..
With all the parts you have put in it your best bet might to be to replace that fuel tank. Sounds like in spite of cleaning it particles are still falling off and clogging strainer and lines. If nothing else it would eliminate it from the list of possible culprits and help to protect your new fuel pump from damage.
"Well, yeah, but the problem is that old gas makes this... I don't even know how to describe it. It's like mud with a thick honey covering, allowed to bake in the sun. I bet it's not only on the sides, it must be on the top too. Dumb hands are too big to get in there."
If that's the case, I agree with 90 GP. Need to replace the tank. Even a small amount of that sludge will give you problems
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