|
#1
|
||||
|
||||
I swapped ALL of the drivetrain and electronics from a '89 Daytona Shelby in to my '87 Daytona Pacifica. It all works, no fault codes, passed emissions, runs strong, but it acts like the fuel is being cut off when engine RPM reaches 4500-4800. Tach has been verified accurate. Any clues?
Thanks, Clair |
#2
|
|||
|
|||
Clair; You didn't say how much boost you are making. The computer will shut you down at around 14 psi, and you can make over 18 if the wastegate isn't working. It could also be a weak coil, plugged fuel filter, weak fuel pump, exhaust restiction (cat ?),etc.
|
#3
|
|||
|
|||
JUST A COUPLE THOUGHTS: DIRTY INJECTORS TRY SLICK 50 F.I. SYNCHRON CLEANER. ALSO POP YOUR DIST CAP AND P/U COIL LOOK AT SHUTTER WHEEL(4 BLADES METAL) SEE IF ITS LOOSE , ABSOLOUTELY NO MOVEMENT ALLOWED. ALSO P/U COIL IS MOST LIKELY ELECTRICAL COMPONENT IF IT RUNS OK COLD BUT ACTS UP MORE WHEN HOT.ALSO TURBO HOSES LOOSE OR LEAKING, FLUCTUATING BOOST GAUGE WILL TELL YOU THAT.ALSO CHECK TIMING BE SURE TO UNPLUG COOLANT SENSOR FIRST AND ENG MUST BE WARM WHEN SETTING TIMING GOOD LUCK ...PRO..
|
#4
|
|||
|
|||
These cars a notorious for bad grounds to the ecm / sensors and actuators espescialy easy to over look when changing over. Check the wastegate for freedom of movement, check the vacuum hoses for integrity and proper routing disconnect both ends of vac lines and blow through them they fill with crud over time espescialy when not in use.Scan tool to ATM mode and operate wastegate and other solenoids while blowing through or have a vacuum source to check operation. Goto iatn.net for the best resource of auto technicians I have found on the web. Good Luck
|
#5
|
|||
|
|||
check your vacum hoses big problem with turbos
|
#6
|
|||
|
|||
Quote:
|
#7
|
||||
|
||||
I have since been able to force it in to recording an overboost code, and the gage on the dash reads as high as 12-14 psi (just under 15, the max on the gage). A while back, I replaced the oil and coolant lines to the turbo bearing, and I had to disconnect the wastegate pushrod from the gate lever. At that time, I checked the wastegate lever for freedom of movement, and it seemed fine. I'm starting to wonder if this is maybe a faulty MAP sensor? Is there a supplement to the FSM that goes through a troubleshooting process like the one I had for my 86 Shelby Charger?
Thanks again, Clair |
#8
|
||||
|
||||
Welcome to overboost shutdown. Check your wastegate solenoid, and all vacuum lines. If the wastegate can doesn't get enough positive pressure, it stays closed. Could be a leak somwhere. Although, not many people complain about TOO much boost.
Greg |
#9
|
||||
|
||||
Problem is still there, but I've refined what I know about it now. It will rev easily to 6K at part throttle, croaks at 5K now at WOT. Since my last post, I have de-gapped the plugs from a loose .040 to a tight .030, replaced cap, rotor, and plug wires, and added a 2.5" converter and 2.5" pipe all the way back with a 2.5" Super Turbo. I'm waiting on the 89 tech manual from DaimlerChrysler which should narrow down the problem. I am nearly convinced that it is a faulty MAP, just from the way it acts. Dash gage never gets much over about 12 PSI. I'd still appreciate any further input, though. I just bought my first Grainger and it's gathering dust waiting to get this sorted out...
Thanks, Clair Quote:
|
#10
|
|||
|
|||
Hey Clair,
I'm in Killeen, practically neighbors. Don't trust your dash boost guage to be accurate. In fact I'll bet it's off and your 12 psi is actually more. The computer uses the MAP sensor to determine manifold pressure. When it sees 14 psi or so it cuts the engine off to prevent damage. The dash boost guage is a neat gadget but not as acurate as it should be and it is not what the computer usues to determine boost levels. maybe you could beg/borrow/buy a real vacuum/boost guage to compare to your dash guage's readings. if you were closer I'd loan you mine. BTW, I believe that 4.7V at the output of the MAP sensor will trigger overboost shutdown. maybe, if you are handy with wire and have a digital voltmeter you could wire the voltmeter in parallel to the MAP sensor output and verify this voltage level is reached when you experience your problems. If so, and you verify that your actually have 12 psi only, then yeah it's your MAP sensor. I don't think it is though, I think it's a poor boost guage accuracy issue. Steve ------------------ 38 Plymouth P6 65 Plymouth Barracuda 87 Dodge Diplomat 89 Plymouth Caravan 96 Dodge Neon "No quarter asked, none given" - Thunderstruck Racing |
#11
|
|||
|
|||
I just remembered, it's 4.7V for the MP computer (higher boost cutoff level) and 4.3V for a stock computer. Hope this is of some use.
Steve |
#12
|
|||
|
|||
geez, i went off on a tangent. While I described what causes an overboost shutdown I didn't tell you how to fix this. There are several ways to do this.
Boost levels are controlled by the wastegate solenoid. The computer cycles this solenoid, which in turn controls the wastegate. This is what sets your boost level. Basically, there is a vacuum line from the intake to the solenoid, then from the solenoid to the wastegate vacuum pot. If the lines are broken or unhooked you have no wastegate control. If the solenoid is faulty you have no control either, but that usually sets a code. Wiring to the solenoid from the computer can cause this too, but it usually sets a code. Maybe you have a bad line, when they get old they can crack and maybe pop off. Another possibility is that the rod from the wastegate vacuum pot to the wastegate itself is disconnected, that would cause a loss of boost control without a code being set, other than overboost that is. This isn't too uncommon. You could do the hot rod method and eliminate the computer control method by using a bleed or a grainger valve. I use this method (grainger) myself for a constant 12 psi. This will allow you to run closer to the cutoff without triggering it and you'll be making more power with more boost. Check out this site for info: http://pages.cthome.net/gus/ Steve |
#13
|
||||
|
||||
I'm looking at getting a "real" boost gage like the Autometer 30/20 I mounted in my 86 Shelby Charger. I need to do that and get an A/F meter, too. This swap took me a long tome to complete... it could be that I left the 87 T1 MAP & solenoids on the firewall, assuming that they were identical to the 89 T2 parts. They LOOK and hook up the same... Do you happen to know if there is a difference? Maybe in the output?
And you're right about Gus - his site, and his minivan, ROCK! Thanks for the tips, Clair Ft. Worth, TX 87 Pacifica T2/A555 74 Swinger 440/727 69 Valiant 340/A833 67 Barracuda convertible ?/A833 Quote:
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
High rise manifold is too high for throttle cable! | gagfitz | Performance Talk | 2 | 07-30-2005 04:16 PM |
High pressure or high volume oil pump | toad490 | Performance Talk | 7 | 12-12-2004 05:12 AM |
3.3 dies | kenkarner | Front Wheel Drive Chat | 3 | 08-10-2003 03:55 PM |
High Pressure of High Volume oil pump? | TwiZtiD440 | Performance Talk | 17 | 08-10-2002 09:27 PM |
Mopar Performance Turbo Computer for '89 2.2L Turbo II (manual trans) | tornqvis | Front Wheel Drive - Parts Wanted | 0 | 09-06-2001 05:29 AM |