87 tona, wont rev past 4500, now is dead.

[kermit]

My money is on a bad injector/dead cylinder. What you should have done is cool down all of the way, start it, and reach back and feel the exhaust manifold. Put your hand on the runner for each cylinder and you should feel them getting warm within a few seconds. If one doesn't then that's your missing cylinder.

Dumb question, but you did check for spark across ALL four.

[TurboDoctah]

Quote:

Originally Posted by kermit My money is on a bad injector/dead cylinder. What you should have done is cool down all of the way, start it, and reach back and feel the exhaust manifold. Put your hand on the runner for each cylinder and you should feel them getting warm within a few seconds. If one doesn't then that's your missing cylinder. Dumb question, but you did check for spark across ALL four.

Yes i have spark on all 4. but #4 fuel injector wasnt spraying at all. that plug was clean and from the vid it does sound oddly like a 3 banger lol.. i pull the plug wire and it makes no diffrence on how it runs.

[tmoney]

when i bought my 89 daytona shelby the knock sensor was cracked and dangling. it was acting the same way. i replaced it and it was alot better. i think it was running retarded all the time . but let is know what the shop finds.....

travis

[TurboDoctah]

Quote:

Originally Posted by tmoney when i bought my 89 daytona shelby the knock sensor was cracked and dangling. it was acting the same way. i replaced it and it was alot better. i think it was running retarded all the time . but let is know what the shop finds..... travis

Will do man. there posed to call me today, i drove past there aw the door open on my car still in the shop bay... so they had to of done something to it lol... just waiting on the call. hopefuly they can get it fixed before my tags expire cuz i still have to put a cat in it to pass e-check. :P

[TurboDoctah]

ok the temp sensor was reading -67* and the map was just saying f u.. he also thinks there mite be some misc wireing problem, so hes putting on a 3 bar map, and a new temp sensor, and if thats all it needs then ill have the car on the road tomorrow for 140 bucks CHEAP! i like this place. ill update tomorrow. now i just need to find 140 bucks laying around lol.

[91CSdaytona2.5]

Quote:

Originally Posted by kermit Dumb question, but you did check for spark across ALL four.

No such thing as a dumb question... I'll take any and all ideas at this point... Mine has no misfire at all at idle so they all fire and get hot until I rev it.
I'll start pulling plug wires when it is rev'd to see if it's consistently one cylinder.

maybe I can close in on the culprit. Anything is worth a try.

TDoc: I'll really be curious what else they might find... I have had a temp sensor code before, although not currently throwing code now. I just figured it was because I had it unplugged checking the timing???

I'll go down and buy a new sensor and give it a try. Using my laser temp pointer thingy, I've got ~190 degrees at the thermostat housing, so I know its getting warm & T-stat not stuck open.

[91CSdaytona2.5]

Quote:

Originally Posted by tmoney when i bought my 89 daytona shelby the knock sensor was cracked and dangling. it was acting the same way. i replaced it and it was alot better. i think it was running retarded all the time . but let is know what the shop finds..... travis

Travis,

that is something I haven't thought about... Where the heck is the knock sensor located???

[1991shelby]

I have a 91 daytona and it also goes flat at 4500. One answer I got was the ignition and cam timing. I have checked the ignition and it is fine. I also think it is in the cam timing. Might have slipped a tooth on the belt. I also got the spark plug answer but I don't buy that. It does not miss just won't climb. If you figure it out before me please post what fixed it and I will do the same. But my money is on the cam timing

[tmoney]

its right between the 2nd and 3rd injectors on the intake manifold. It didn't even set faults either

Travis

[gerbot_3000]

I'm having freaky misfires at 3300-4000 and that's all i can get of the engine, it feels real good when its revving, but when it gets to that point, it just feels like it's doing nothing and sounds like shooting a machine gun... i dont know if that is what is called misfiring

[tmoney]

Quote:

Originally Posted by gerbot_3000 I'm having freaky misfires at 3300-4000 and that's all i can get of the engine, it feels real good when its revving, but when it gets to that point, it just feels like it's doing nothing and sounds like shooting a machine gun... i dont know if that is what is called misfiring

thats what mine is starting to do now. im gonna get an hep. thats the only thing i havent gotten yet

[speedfreek09]

i also got a question mine runs great in the morning, no missfiring boosts great all through the powerband, but after it gets warm after driving it for a while, it starts to do the same thing starts missfiring at 3,700rpm and wont rev past 4,500, also wont boost the same morning 16-18 after a while 13-15 and unsteady, little backround 87 daytona TII FM E2 turbo, computer and fuel mods to work with it. i should be able to do a couple more things and run 25psi like i want to. but i gotta figure out the problem first. oh yeah, it was doing this before and after replacing the hep

[91CSdaytona2.5]

Quote:

Originally Posted by FFWD The only time I had something like that happen, my cam timing was off. I think a tooth retarded. Check that.

Well, I have had my head completely up my A$$.
Using a timing light to check cam timing is NOT accurate! There is way too much tolerance between the hole in the cover and the mark on the pulley. I was a tooth off (And have been for a long long time apparently unless it slipped a tooth somehow). I pulled the thing all apart, got out my straight edge and lined up all the marks... Bottom end was good, but the top was off.

She'll rev to the moon now. Only thing left I have to figure out is why my tach is intermittently not working. I can turn my boost back up and go for a ride

Thanks to all who have chimed in and at least got me headed in the right direction. TDoc, what did that shop figure out on yours???

[91CSdaytona2.5]

Quote:

Originally Posted by 1991shelby I have a 91 daytona and it also goes flat at 4500. One answer I got was the ignition and cam timing. I have checked the ignition and it is fine. I also think it is in the cam timing. Might have slipped a tooth on the belt. I also got the spark plug answer but I don't buy that. It does not miss just won't climb. If you figure it out before me please post what fixed it and I will do the same. But my money is on the cam timing

I'd bet $$ on your cam timing too... I went thru the entire process as if I was putting a new belt on it (Mine was pretty new anyhow so I didn't change it)
Took it all apart so I could see the marks... The top one is deceiving unless you have the valve cover off.
Mine's running great now! Keep us posted?

[Adam]

Ah yes the 4500 rpm spark scatter... I fought this same problem for 2 months. The car sat over winter and when I brought it out I coulda swore some one stuck a two step on it and was ****ing with me. After much agony wasted money and wiring harness teardown I went to drain my oil for a trip to carlsile and found a interesting gold metal flake color to it. I pulled my pan and got to looking around and found that the oil pump drive gear was damn near worn off. this gear also drives your dist. play here causes massive spark scatter. i put a new mopar pump and intermediate shaft in it. problem solved.