When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Alright, I'm a new OBS Ford owner coming from almost exclusively GMs and Im having an issue with this Truck's EGR system.
Long story short: I got this '93 F150 with the 5.8 EFI V8. It has around 200k miles on it. The previous owner deleted the EGR system by what looks like cutting the down pipe and using a block off plate. The truck ran and drove okay but it had the CEL it up. I go to replace the EGR components, including a new valve, down pipe, pigtail, evp(?) sensor and vacuum lines. The check engine light goes away, but as soon as I shift the truck into drive, it immediately stalls and dies. I can't even it drive it around the block. The only way for it to stay running now is to unplug the EGR, but then the CEL comes back on. The previous owner won't answer my questions about whether or not he messed with the ECU so I'm really not sure what's going on here.
My questions are: 1) is this common on these old Ford's? 2) How can I diagnose the issue properly, and 3) if anyone has a clue what's going on here, how can I fix it? Like do I need the ECU programmed some kind of way or anything?
What little I know, when you say unplug, do you mean the electrical(plug), or the vacuum line, if vacuum line then you either have a bad solenoid, that is letting vacuum by, or the wrong solenoid, 5.8L had 3solenoid by the ignition coil, make sure you have the correct one, and there was 2 EVp valves, one was white, one was grey/lite grey, also caused issues, with knock offs stem is too long and pushes it open. I would get a vacuum gauge and check the green tube coming from solenoid, should be 0 inches of vacuum, at idle, on green tube.
p.s.he could't/didnt do anything to ECM, to turn it off, or on
Where did you connect the EGR vacuum line? If it was directly to manifold vacuum that is your problem, it has to be connected to a control solenoid (EVR) which is usually right next to the ignition coil on the same bracket.
What little I know, when you say unplug, do you mean the electrical(plug), or the vacuum line, if vacuum line then you either have a bad solenoid, that is letting vacuum by, or the wrong solenoid, 5.8L had 3solenoid by the ignition coil, make sure you have the correct one, and there was 2 EVp valves, one was white, one was grey/lite grey, also caused issues, with knock offs stem is too long and pushes it open. I would get a vacuum gauge and check the green tube coming from solenoid, should be 0 inches of vacuum, at idle, on green tube.
p.s.he could't/didnt do anything to ECM, to turn it off, or on
I meant to say unplug the connector, not the vacuum line. But I will get a vacuum gauge and test it. Out of all the tools I've acquired in my garage, that's one I don't have. Thank you for the suggestion.
And if I'm understanding you right, you're saying that whatever the problem is, it *cannot* be ECM related?
Where did you connect the EGR vacuum line? If it was directly to manifold vacuum that is your problem, it has to be connected to a control solenoid (EVR) which is usually right next to the ignition coil on the same bracket.
My EGR line is connected right to the EVR unit where the green line is in your picture
The EGR normally has no perceptable effect on engine operation so something isn't right. Can you pull codes and if so what codes are stored? If you get no codes or no response from the PCM it has a problem.
I have no idea what is wrong with your engine, but if the EGR valve is on [vacuum applied] all the time, the engine will run bad.....real bad. Basically, it's allowing exhaust to enter the intake. A little bit solves some emissions issues, but too much is really going to hinder the combustion cycle.
I suspect you might have electrical issues, but it's also possible that the vacuum lines/hoses are not routed properly. A vacuum test at the EGR valve should shed some light on your issue. Usually, there should be no/very little vacuum at the valve at idle. As the throttle is opened, you should get a higher vacuum reading.
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
