2.9L HELP!
2.9L HELP!
i recently just purchased my 87 ranger about 2 weeks ago, it has the 2.9L and 5 speed manual transmission. yesterday was the first day i really got on it besides the test drive, and it seems to be super low on power, and sometimes right after shifting it just bogs down and goes no where, when taking off from 1st or reverse, its almost like you HAVE to ride the clutch for it to go or it dies.. also at first start up it idles high, like 1700-2000 high.. and then fails to drop down to 1000 before 5 minutes, and while driving its basically idling at 2000.. any help would be greatly appreciated!
Last edited by ranger_redneck; Nov 5, 2014 at 11:36 AM.
Sorry missed it the first time.
2.9l is a good engine, the 1987 fuel injection is a Speed Density system/computer which is OK, but can have problems.
On the upper front of the intake will be the IAC(idle air control) Valve, it looks like a can, inside is an electric motor that opens and closes a valve that lets more or less air into the intake, the computer controls this motor/valve, this is what sets the idle RPMs.
When engine is warmed up unplug the wires from the IAC valve, RPMs should drop to 500, or engine may even stall, either is OK, but it means the high idle is being caused by the computer.
If idle stays high then you have a vacuum leak, start checking the hoses, or IAC valve may be sticking, these can be cleaned.
Speed Density uses a MAP(manifold pressure) sensor to control the flow of fuel.
MAP sensor is on the firewall(passenger side towards the middle) usually behind the main wiring harness, it has a Vacuum line from the intake manifold, find the MAP sensor and check this vacuum line, remove it and make sure it is air tight.
MAP sensor itself rarely fails, check its connectors wires, unplug it and make sure contacts are clean and dry.
Next stop will be TFI spark system, it will have problems at 27 years old.
Good read here on testing it's parts: Ford EEC-IV/TFI-IV Electronic Engine Control Troubleshooting
Your symptoms could be wrong fuel/air mix or bad spark advance
2.9l is a good engine, the 1987 fuel injection is a Speed Density system/computer which is OK, but can have problems.
On the upper front of the intake will be the IAC(idle air control) Valve, it looks like a can, inside is an electric motor that opens and closes a valve that lets more or less air into the intake, the computer controls this motor/valve, this is what sets the idle RPMs.
When engine is warmed up unplug the wires from the IAC valve, RPMs should drop to 500, or engine may even stall, either is OK, but it means the high idle is being caused by the computer.
If idle stays high then you have a vacuum leak, start checking the hoses, or IAC valve may be sticking, these can be cleaned.
Speed Density uses a MAP(manifold pressure) sensor to control the flow of fuel.
MAP sensor is on the firewall(passenger side towards the middle) usually behind the main wiring harness, it has a Vacuum line from the intake manifold, find the MAP sensor and check this vacuum line, remove it and make sure it is air tight.
MAP sensor itself rarely fails, check its connectors wires, unplug it and make sure contacts are clean and dry.
Next stop will be TFI spark system, it will have problems at 27 years old.
Good read here on testing it's parts: Ford EEC-IV/TFI-IV Electronic Engine Control Troubleshooting
Your symptoms could be wrong fuel/air mix or bad spark advance
i will try a few of those things! i did the KOEO, and KOER tests and got a dtc 33 for egr valve, i have yet to check that any farther. i have the new egr its just too cold to change it out right now. i also found one broken vacuum line, and did a simple fix for now, and that helped, but it still idles pretty high, (1200-1700). Also, every once in awhile i smell gas pretty bad. i unplugged the battery for awhile after fixing the broken vacuum line while hooking my lights up and still got the same dtc code after that. so the egr i will try next. any other suggestions? also, yesterday, i was leaving for work, i backed up in reverse, and it just quit on me and then would not start again. i had to let it sit for 4-5 hours before it would start again.
Yes, EGR system could cause some of the symptoms.
This system has 3 parts, + the computer, that make the system work correctly.
1. EGR solenoid/modulator, this is an electric valve that controls the vacuum going to the EGR Valve, computer controls this solenoid.
It will have an electrical connector and 2 vacuum hoses, one to EGR valve and one to Intake manifold.
2. EGR valve sensor, EVP or DPFE, this tells the computer if EGR valve is opening and how much it is opening, on your year there will probably be an EVP sensor on the EGR valve, it will have an electrical connector.
3. EGR Valve, this opens to let exhaust gas mix with air/fuel in the intake manifold, but only when engine is under load, this cools down the cylinders which reduces NOx emissions and also reduces pinging(pre-ignition).
Code 33 doesn't mean EGR valve is bad, it means computer can not read that EGR valve is opening.
So it could be EGR modulator has a vacuum leak and can not open EGR valve as much as it should, or is stuck open causing vacuum at EGR Valve all the time.
EVP sensor is not telling computer EGR valve is opening
EGR Valve is stuck open, which would cause sluggish performance.
Couple of tests
Unhook EGR valve's vacuum hose and plug the end of the hose.
Start engine
Remove the plug on EGRs vacuum hose, there should be no vacuum present, if there is then EGR Modulator is bad.............or computer is.
Put another vacuum hose on the EGR and suck on it, opening EGR valve, engine should start running rough and eventually stall, if that doesn't happen the EGR valve is stuck, clean or replace.
If engine does run rough or stall with above test, leave EGR's vacuum hose disconnected and plugged up.
Go for a drive and see if engine runs better, if it does then EVP sensor or EGR modulator is the problem........or computer, system is opening EGR Valve when it shouldn't or opening it too much for engine RPMs
This system has 3 parts, + the computer, that make the system work correctly.
1. EGR solenoid/modulator, this is an electric valve that controls the vacuum going to the EGR Valve, computer controls this solenoid.
It will have an electrical connector and 2 vacuum hoses, one to EGR valve and one to Intake manifold.
2. EGR valve sensor, EVP or DPFE, this tells the computer if EGR valve is opening and how much it is opening, on your year there will probably be an EVP sensor on the EGR valve, it will have an electrical connector.
3. EGR Valve, this opens to let exhaust gas mix with air/fuel in the intake manifold, but only when engine is under load, this cools down the cylinders which reduces NOx emissions and also reduces pinging(pre-ignition).
Code 33 doesn't mean EGR valve is bad, it means computer can not read that EGR valve is opening.
So it could be EGR modulator has a vacuum leak and can not open EGR valve as much as it should, or is stuck open causing vacuum at EGR Valve all the time.
EVP sensor is not telling computer EGR valve is opening
EGR Valve is stuck open, which would cause sluggish performance.
Couple of tests
Unhook EGR valve's vacuum hose and plug the end of the hose.
Start engine
Remove the plug on EGRs vacuum hose, there should be no vacuum present, if there is then EGR Modulator is bad.............or computer is.
Put another vacuum hose on the EGR and suck on it, opening EGR valve, engine should start running rough and eventually stall, if that doesn't happen the EGR valve is stuck, clean or replace.
If engine does run rough or stall with above test, leave EGR's vacuum hose disconnected and plugged up.
Go for a drive and see if engine runs better, if it does then EVP sensor or EGR modulator is the problem........or computer, system is opening EGR Valve when it shouldn't or opening it too much for engine RPMs
Last edited by RonD; Nov 13, 2014 at 09:12 PM.
tried all those tests, nothing happened, so i replaced the egr, cleaned the IAC, and found a wire that kept shorting out on my powersteering pump, so that fixed the dying problem i had while turning.. but it is stillspitting and sputtering under load :/ What next?
update: i replaced the egr, no difference, it doesnt die anymore which is a big +, but it still smells like gas bad, and is getting horrid fuel mileage. i hooked a fuel pressure gauge up to it, and turned the ignition on, it jumped right up to 35-40 pounds, but after about 3 seconds it looses all fuel pressure.. would this be a pump issue?
update: i replaced the egr, no difference, it doesnt die anymore which is a big +, but it still smells like gas bad, and is getting horrid fuel mileage. i hooked a fuel pressure gauge up to it, and turned the ignition on, it jumped right up to 35-40 pounds, but after about 3 seconds it looses all fuel pressure.. would this be a pump issue?
And wouldn't be a return line issue since pressure went up to 40psi, and if FPR was bad you would get may be 10psi at rail.
I think the '87 had 2 fuel pumps, low pressure pump in tank and high pressure pump in the frame under drivers seat area.
Fuel line from high pressure pump to fuel rail is leaking, if you are losing pressure that fast.
Check at fuel filter first, those connections can leak.
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