Another 4200 RPM stumbling/cutting out question...

[93turqxj]

I also have a titan 4.9..... I know wish i would have done some research...

Mine cuts out at about 3800 rpms, like its hitting a studder box

so is the consensus on the hittting the wall issue always valve float?

[93turqxj]

So talked to chuck today...

He said it sounds like my timing is off. I don't see how but I will triple check and get back to him

He said valve float is unlikely... But possible. Idk ill check timing and update

[SilverXJ]

You can check your timing, but if it runs at all other points I doubt that is the problem. Valve float is likely. However, I would check your fuel pressure first. You may want to drive with a gauge taped to the windshield as some fuel issues (like a weak pump) won't show up at no load/idle conditions.

[93turqxj]

well i checked at idle all good but i do have a code 13, no signal from map at start up

map sensor could cause this?

i think it is going bad cause i can barely keep t running now

[SilverXJ]

Yes it could. When in open loop the MAP is the primary factor in determining how much fuel to add.

[93turqxj]

Replaced map sensor, will idle now.... But still hitting a wall at 3800

Not the fuel pump because in park it will hit a wall as well and the frp was 40 wot hitting the wall

I'm running out of options other than valve float.

[JeepFamily]

My son and I are building a 97 ZJ stroker and we are stuck choosing the cam. I would like to inquire a bit on the conditions your mileage dropped when changing to the 232 cam.

1. What were the driving conditions, all highway, combine in town highway, off road, etc?
2. What is your engine rpm at say 65 mph?

[SilverXJ]

Nice that it does it at idle.. at least its easy to diagnose. Have you checked the TPS? I wonder if a failing/weak CPS could cause an issue like this.

[93turqxj]

how do you check a tps?? resistance i guess?
i thought a crank sensor worked or didnt work, nothing in between because it reads on pulses.

so are you thinking not valve float if it does it in park?

[SilverXJ]

I don't know if valve float would happen in park or not, but i wouldn't rule it out.

See here how to test TPS http://www.quadratecforum.com/showthread.php?t=72101

Basically, conned a multi meter between the ground and out to PCM and watch the voltage change from ~.4 volts to ~4.8 volts. If it jumps or stops its bad. An analog meter is best for this.

[93turqxj]

Yea i went ahead and replaced it.. no dice still hitting that wall.

what else cps? im pretty much at my wits end, im trying to rule out all possibilitys other than valve float

[93turqxj]

replaced cps still no dice

idk whats up... wtf

[F1boats]

You are having valve float do not go any further! Titan has stepped up there game in the last 2 months I think new management and at least 1 new guy in the shop Worthy he is great! Chuck seems like a nice guy but kept telling me there is no way it's floating the valves. I changed everything electrical part that you could with no change, valves would float in park at 4200! I Sent the motor back Worthy went thru it BINGO bad valves springs no seat pressure they said they got a bad batch. Only have 250 miles on the motor but it seems very strong! Still have a bad lean issue above 4400 now but that has nothing to do with the motor they built. One strange thing I have now is when the motor is cold pulling out of my driveway it will pull hard to the redline to the first stop sign but not to the second stop sign ???????????????????????? Any help with that would be great. Ordering wide band air/fuel data logger with a OBD2 plug to log codes as well. When I get this tuned I believe it is going to be bad ass!
One last thing Titan and Worthy did come thru they warranty EVERYTHING except the motor coming in and out put all new bearings Ect. like it was a fresh built motor not something they through together even gave me a new crank balancer paid for shipping very cool !

[Cheromaniac]

Still have a bad lean issue above 4400 now but that has nothing to do with the motor they built. One strange thing I have now is when the motor is cold pulling out of my driveway it will pull hard to the redline to the first stop sign but not to the second stop sign ???????????????????????? Any help with that would be great.

The engine runs richer when it's cold so that would explain it.

[93turqxj]

Got titan to send me springs, he sent me some last week... had the jeep apart to find the valve springs he gave me were too small.......

called him (chuck) he said "ohhh you have conical springs... i know what you need"....

got the supposed right ones today, the same damn ones he gave me the last go around...

stilll waiting on the right ones its been over a month since i put the motor in, can hill climb off road cause i cnt go over 3750 and the tranny wont shift unless i get off the gas and by that time ive lost all momentum and cant get up the hill.... i cant do anything off road with my titan monster.........