Timmie

Have this problem now for quite a while now.
when my car is cold, it pulls very good ( specially for a v6 )
this is for like 6 minutes or so.
after that all the power is gone and I think I even have a problem holding on to a prius.
think about 0 to 60 in 15 secs or so.

if you would check it on idle. you can really hear the engine drop a couple of rpm after 6 minutes or so. I have this problem on gasoline as on propane. and I really don't have any clue where to look at.

its like i'm king of the streets for 6 minutes after start. and after that its gone.


ow, the car is an enginewise completely stock 91 camaro RS V6 3.1 with th700R4 transmission and stock rear

zs&tas

hey, any changes to it recently?? service or anything?? try checking temp sensors?? ecu maybe sending wrong signals if it thinks its still cold could be overfueling which would make you really slow.
and o2 sensor maybe not working when hot??(unlikly)
does it actually run smooth? just short on hp?

Timmie

the car had this problem from hen I bought it. 2 years ago :$
havent checked temp sensor. do know that my temp gauge does show all the values. altough on highway speed its more leaning towards the 100 degrees than towards the 220 degrees. and when hot its gong above the 220. before the fan kicks in.
ecu, dont know, dont even know how to check this.
overfueling, i would find that weird, since he runs great when cold ( first 6 minutes )
o2 sensor, was thinking about that 2, but they say that when you switch to propane, it uses somkind of other sensor that always gives 0.5V. not shure about this.
on propaan the car runs very smooth, but when you drive it you can feel the engin trying, making noice, you can see it tring to speed up. but just no go.
on gasoline, it doesnt run wel for a tank. ( switching from propane pack to gasoline is a change in octane levels from 108 propane to 98 gasoline ( 93 in USA) wich makes the car make small backfires for a while till the computer learned the new values. after that it does the same thing as on propane.
( same problems )

Derickab

Check the fuel filter. I hope you changed it when you switched your grade of gasoline. You might even want to look at the pump later but the filter for now should be fine if it sthe problem.

Timmie

iw ill check on the fuel filter. god knows how long that thing is underneath there ( could be a matching number part). btw, would also be a bit weird since when I start the car when its still warm, like waiting 15 mintes or so. I still got the problem of moving like a turtle.
but that doesn't explain why he is holding back on me on propane ?
more ideas are always welcome.

83camaro86

iTrader: (1)

when you are runing propane is the carb frezen up. Cause as you know propane is cold and will freze up on some cars/trucks. I work for a propane company and use to drive a deliver truck that did that sometimes. IT would just kill the motor like it was out of propane. Can i get a pic of the setup for propane

Timmie

nope, freezing of the carb only happens when its really cold outside ( freezing temps ) and I would hit the gas when its still cold then.

BLACK ICE

Ok I gotta ask! How did you end up with a grey dash and center console???

Timmie

hehe. wel I originally had a grey leather interior, with a black dash completely stock.
problem is. the front seats were really ripped. plus during hard cornering I went from left to right in my seats.

I found sombody on the forum. with a broken down completely custom firebird. ( flashy green with purple exterior, zz4 block, and the white interior )
only thing the builder didnt change was the rear axle. 400 hp + v6 axle = no good. so his wife drove the car around and against 40mph the rear end drilled its way into the interior. ( he bought that firebird for 20000 euro )
due he needed money pretty bad he sold all the parts seperatly.
I bought the interior for 400 euro. + he helped me installing i.
so the white vinyl seats are from the firebird. the T-roof and everething comes from the firebird. problem is. some parts from the car like the dash werent the same. so we used the camaro dash again. but since everething was out of the car. we could first paint it white/greyish.

you can also see on the pic that the upper plastic door part ( against the window) is made out of somekind of fake wood material. also used on the center console.
on the original car ( was a 84 firebird ) the same kind of wood was around the shiftplate.
( note , even center consoles dont match, so we repainted mine . then took the white vinyl clothing of his center. en put it around mine. ( under the vinyl you put a bit of mush to give it the softer feeling.


ow, before you ever go for white. do note that sometimes due to reflection i can see my own dash into the front window so I advice while driving you put a black towl over the dash.


got anymore questions, just ask private. want to keep this topic strictly for my engineproblems.

Street Lethal

iTrader: (16)

... your running a carbed 3.1 lol?

All factory engines run better during Open Loop, in fact, may people run a strictly Open Loop tune....

Timmie

nope, but the LPG works trough carb, it is connected by a pipe to the intakemanifold. and it works on vacuum that the engine sucks.
the carb of the lpg sits near my coolant tank. ( ****ing weird setup but i bought it like that) if i could choose myself would have taken a gas injection setup that would spray straight into the manifold.

Street Lethal

iTrader: (16)

^ Can you post up a picture of the engine....?

Timmie

its not exactly a great picture, will post a better 1 tomorrow ( after my exams ) = its dark now outside. on the black piece of pipe almost in the middle there is a T-connection made to the underside of the pipe. trough this it sucks the lpg trough a pipe that ends up at somekind of carb located between the silver pipe, the watertank and the alternator.



( note about the black silver pipe ) I already lost 2 original airpipes ( they broke in 2 or something ) those things cost 50 euro's new and if i'm got bad luck they break down again.
this piece of pipe is 90mm endable pipe costs 10 bucks in your local hardware store, its hasn't got any leaks and it does its job much better than the orignal piping.
( its the kind of piping thats used to suck air away abouve your kitchen fire ) don't know how its called in english.

Street Lethal

iTrader: (16)

^ Yeah, I'd definitely like to see some more pics, as I've contemplated the switch many times. The problem with propane though is that you'd have to burn more of it to make the very same power as you would with regular gasoline (especially with the stock 3.1's compression levels)....

Timmie

yups, I know about that part. but i also know there are some very good type of installations ( i know there is 1 where your original injector are put on top of the propane injectors) so when you switch over from gasoline to LPG, you stil have the same type of injection as witch gasoline. almost no losses.

nutcase-mark

That what my 3.1 firebird did before the water pump went out

Timmie

mark, i would find it weird that a bad waterpump would make your car run bad.

nutcase-mark

i known, but the same thing that is happening to your car happen to mine and right after I put a new water pump on it, it stop doing it. And you can also take your radiator cap off and see how good the water is going done, if it is not going down good it is the water pump.

Timmie

other question, do the moments your transmission shift change during temperature climbing.
I have the feeling that when the car is getting hotter, the transmission shifts up a lot later then when its cold. ( both times kicking the pedal to the ground)
when hot it looks like the engine is going over its top power before shifting.
its like shifting to slow/late on a stick car.

Kevman

Plugs, wires, cap and rotor... First thing to change when something goes wrong.

Timmie

already done that

nixon5

if you figure out what was wrong let me know cuz im haveing that problem also. when i go out in the morning and its like 30* it runs great and feels pretty powerfull until the engine heats up then it feels sluggish compared to all the other cars around me.

Timmie

still don't know it. i meant , I already changed the spark plugs, the wires 2x, the rotor, cap and ignition module.
still havent found a solution.

zs&tas

any news on this? did you get the codes???

Timmie

havent done anything yet due to the fact that I'm in the middle of my exams.
I let you know something when I checked out my sensors.
temp, throttle position, and so on.

jstrdn90rs

Does it still have the Cat Convertor on it?..almost sounds like a plugged exhaust?..if so unbolt it and drive it ?.possible Propane too rich for Catty Convertor? if no change there might be a torque convertor wanting a vacation to the junkyard beach?..just my

Darkshot

iTrader: (4)

Just a guess but maybe O2 sensor? Sounds about right that the engine starts running bad once it enters closed loop and is using the O2 sensor. Just a guess though. I am slightly intimidated about giving advice on a propane engine I know nothing about

Timmie

I'm thinking that way 2.

but I guess im gonna hav to search the lines 2 since you actually have 2 )2 sensors.
1) is your normal in the exhaust sensor. ( this 1 was not connected when I bought it ) I reinstalle 1 with my second hand exhaust.

2) the second 1 is when you drive on propane, its somekind of unit that always gives 0.5V to the computer. Now I have the problem on gasoline and propane.

I just hope they put somekind of switch between the 2 sensors and they didn't just put them parallel to eachother on the same line. since that would explain a lot.

on the other hand, the question why I asked about the transmission shift points is because every time my engine is hot it feels like I can rev it higher then when its cold before it shifts. but to check this i'm gonna order some nordskog gauges since from my original gauges only the speedometer can be trusted. my gauge says my battery is giving close to 18V when alternator is running ( 13.5V )
my oil pressure can go from 60 psi ( if you disconnect the wire ) instead of 80.
to way below -20 psi instead of 0 psi. ( a car that can suck vacuum on the oil system :P )
my temperature gauge ( oh wel don't know if its running correct but I find it hard to read if between the first half of the meter its 120 degrees range ( 100 to 220 ) and the the second halve its only a 40 degrees range ( 220 to 260 )
my fuel level can sweep half a tank when I brake or take a right turn.
and my tach, well lets see its says 2000rpm when I'm actually running 800rpm.
and on the speedway against 120km/h ( 80mph ) it says 7000rpm instead of 2200rpm ( it aint very hard to redline my car )




ow about the sensor problem, forgot to mention 1 thing. I suck fuel like there is no tomorrow. i think I will go close to 20L/100km
if you know that a camaro tank is only 60L. that would mean 300km on a tank or 200 miles on a tank of gas.

ScottieB

i assume this is a 2nd or 3rd hand car? make sure it is properly burning the gas. mine ran great for a couple of mins when it first started up... it turned out that i needed to advance the distributor some. now it runs like a champ again! when i cleaned out the intake i had to take out the dizzy, and i didn't put it at the right angle... so that was my problem. check it imo.

Blue1989RS

A while back ago my V6 car did the same sort of thing. Ended up being the EGR vacuum control valve was stuck open. If you have a vacuum (non-digital) EGR valve, try disconnecting the vacuum hose and plug the hose with a golf tee or bolt.

Hope this helps.

ohiotemplar

Try running it with no thermo on the highway for awhile. If it doesn't lose power at all you'll know you're losing power b/c of closed loop operation. Then you know it's prolly that o2 sensor. Also, in some cars the radiator cap is spring-loaded and matters very much in the running of the car. I don't know if that's true with our cars but it's something to think about.

Timmie

ok, I just detached the o2 sensor, and he still has te problems.
to blue89rs, I have a digital EGR.

just a quick other question.
I know where the temperature sensors is located ( the one for the ecm ) gront of engine next to thermostat housing.

but the 1 for the gauge, where is that one located? its suposed to be a dark green wire that goes to it. but I don't know where that sender is located.

Travis&camaro

Does any on know?? I Have them same problem.

Timmie

yes , I'm a bid further now.
it on my car it has something to do with code 43.
so or my ignition module is bad. could be but i doubt it
or more likely my knock sensor is not giving any knocks. anyway, I ordered another knock sensor together and I'm building myself an ALDL cable.
if my ecm still doesn't give a knock then ( also while check my wiring )

I will have to advance my timing a bit. I'm running on premium and E84.
so it could be that the octanelevels are to high to even get a knock.
so by advancing the timing a bit I want to try to let him pas the knocktest wich will make him not go into limb home mode.

BlueShark

i have a 1990 V6 3.1L and mine runs very good when cold, but not for long, same as yours. basically its like having a cold air intake on your car, for that short amount of time. My suggestion is to buy an intake for your car, it will make your car run like it did in those 6 minutes. There shouldnt be anything wrong with your car.