Code 41 Is this the ECM or the injectors?
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Tuned
Joined: Aug 2007
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Code 41 Is this the ECM or the injectors?
1988 F250 351 5.8
I've worked for months on this truck and I now have it in the shop. The truck shows a 41 code and has a lean miss at idle that get worse during acceleration and cruise. The injectors were refurbished 6 months ago and the ECM was replaced 3 months ago. All sensors are new and within specs. Fuel pressure is good and there are no vacuum leaks.
The mechanic has verified that the condition is not electrical related. The O2 sensor will react if carb cleaner is sprayed into the throttle but other wise shows constantly lean. He's now checking all pins at the computer for any off condition. He is suspicious of the refurbished injectors. I'm wondering if the computer somehow went out again.
Any thoughts on which way to go or what/how next to test?
I've worked for months on this truck and I now have it in the shop. The truck shows a 41 code and has a lean miss at idle that get worse during acceleration and cruise. The injectors were refurbished 6 months ago and the ECM was replaced 3 months ago. All sensors are new and within specs. Fuel pressure is good and there are no vacuum leaks.
The mechanic has verified that the condition is not electrical related. The O2 sensor will react if carb cleaner is sprayed into the throttle but other wise shows constantly lean. He's now checking all pins at the computer for any off condition. He is suspicious of the refurbished injectors. I'm wondering if the computer somehow went out again.
Any thoughts on which way to go or what/how next to test?
Fleet Owner
Joined: Aug 2005
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From: Easton,Ks
Originally Posted by jemini
Yes they are the original injectors that came with the truck in 1988 - just refurbished.
The injectors can do this also if they were rebuilt with the wrong parts (changing them to a lower rated injector).
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Tuned
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The FPR reads 34 idle and 39 without the vacuum line. The pumps are all new. If I snap the throttle wide open with the vacuum line off the FPR, the fuel gauge doesn't show any reduction in pressure - stays at 39 PSI.
The mechanic checked all pins out of the EEC. Everthing checked out within specs. He said he was reading a 5 to 6 millsec pulse width at hot idle. The specs sheet said 4 to 5 millsec was normal so if anything the engine should be receiving a little more fuel than the ideal.
The refurbishing of the injectors consisted of ultrasonic cleaning, new filter, O rings, spacers and pintle caps. They were also pattern and flow tested to within 2% of each other. They seem to work great a few months ago.
The EEC ran the truck perfect for several months before this condition started. Since the computer is under warranty, I've ordered a replacement which will come in in a few days. If this works great, otherwise what else could it be but the injectors?
The mechanic checked all pins out of the EEC. Everthing checked out within specs. He said he was reading a 5 to 6 millsec pulse width at hot idle. The specs sheet said 4 to 5 millsec was normal so if anything the engine should be receiving a little more fuel than the ideal.
The refurbishing of the injectors consisted of ultrasonic cleaning, new filter, O rings, spacers and pintle caps. They were also pattern and flow tested to within 2% of each other. They seem to work great a few months ago.
The EEC ran the truck perfect for several months before this condition started. Since the computer is under warranty, I've ordered a replacement which will come in in a few days. If this works great, otherwise what else could it be but the injectors?
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Tuned
Joined: Aug 2007
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Thanks Bill
The EGR has a temporary block over it to eliminate any possible air leak. The TPS is new and reading between .9 and .95 DCV.
The condition is almost identical to what I've felt with bad wires or a clogged fuel filter. It feels like an electrical miss which is why I replace the new wires and coil and plugs without success before bring it to the shop. The mechanic checked everything electrical out and is certain that the condition is not ignition related but is the lean miss. He felt that carb cleaner, sprayed in the TB, which cause the engine to smooth out and the O2 sensor to temporaraly register something other that constanly lean was the telling indicator.
The EGR has a temporary block over it to eliminate any possible air leak. The TPS is new and reading between .9 and .95 DCV.
The condition is almost identical to what I've felt with bad wires or a clogged fuel filter. It feels like an electrical miss which is why I replace the new wires and coil and plugs without success before bring it to the shop. The mechanic checked everything electrical out and is certain that the condition is not ignition related but is the lean miss. He felt that carb cleaner, sprayed in the TB, which cause the engine to smooth out and the O2 sensor to temporaraly register something other that constanly lean was the telling indicator.
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http://www.autozone.com/autozone/rep...96b43f8038ecd6
ECC IV code 41 i just chased this on 88 ranger the HEGO O2 sensor 3 sensors all got this error after a week or 2 the problem was the heater circuit to the HEGO i traced the power from the key to a fused link the link was good but the wire to it was corroded in half so no power to the heater side of the O2 sensor see if your getting power to heater on the O2 sensor on a Bosch O2 they are both white but they hook to a gray/yellow on a 87/88 ranger Autozone has some good wiring diagrams that will tell u witch wire to chase
I just looked it up F250 same wire gray with yellow stripe here is the link to the wiring diagram for 88 F250
http://www.autozone.com/autozone/rep...96b43f8038ecd6
ECC IV code 41 i just chased this on 88 ranger the HEGO O2 sensor 3 sensors all got this error after a week or 2 the problem was the heater circuit to the HEGO i traced the power from the key to a fused link the link was good but the wire to it was corroded in half so no power to the heater side of the O2 sensor see if your getting power to heater on the O2 sensor on a Bosch O2 they are both white but they hook to a gray/yellow on a 87/88 ranger Autozone has some good wiring diagrams that will tell u witch wire to chase
I just looked it up F250 same wire gray with yellow stripe here is the link to the wiring diagram for 88 F250
http://www.autozone.com/autozone/rep...96b43f8038ecd6
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