Hello,

I am brand new to the list and, following directions, I stopped to read the first two messages.

In the second second message I was referred to the Technical Information section, where I found some info I needed badly regarding the cruise control on my 87 4wd B2, but I went down to the EVAP and the EGR and EGR Troubleshooting info and can't get the links to work or I'm told the information has been moved.

Can someone tell me where to find this information (which I hope includes diagrams for us visual learners)?

I getting at best 15 mpg from my 2.9L and I have some exhausts leaks that I strongly suspect are throwing the EGR and computer fuel delivery out of whack. I need a diagram of the EGR system because I have what I believe to be an exhaust feedback tube that has visible pinholes in it and I suspect larger holes on the underside.

Over the past several months I have replaced the EGR valve, the mass air flow sensor, the IAC, the IAT, the FPR and the oxygen sensor.

To add insult to injury, I can't find my Haynes manual now that I'm ready to return to the scene of the crime and try again (the spousal hide-the-manual trick, I suspect).

Any thoughts other possible causes of my poor gas mileage.

All suggestions or thoughts are greatly appreciated.

Thanks,
Dwight

 

hello welcome to the forum are you sure you have a mass air flow sensor and not a map sensor. only bronco2's that came with maf are from california.

ask for ken00 or mr.shorty

 

Monty,
Unfortunately the manilla envelope with parts receipts was tucked inside the Haynes manual which is MIA, but I suspect you are correct since this B2 came from NYC when I saved it from a slow, rust-related death a year ago.

At this point the depth of my intelligent conversation on the subject stops at "lots of pretty, shiny new parts on the top and back of the intake manifold". I could be more specific with a labeled picture to go by.

Thanks,
Dwight

 

Welcome to FTE!!!

I replied to your PM.

Have you tried pulling the codes? Also check the vacuum line going to the fuel pressure regulator for gas after it has been running for a few minutes, gas means the FPR is bad. A fuel pressure test would be a good thing to run too.

 

Ken - Thanks for responding to the PM and the post.

Monty, et. al.,

I pulled codes this morning and the only one I get is a continuous memory code of 18. This brings up another question. What is the SPOUT circuit?

I have had a short that has been running down the battery, but while tracking that down this morning, I found that the main plug (2 big wires, 1 little wire) on the alternator is shorting on the middle wire, and the post for the little wire on the end is broken in the alternator plug housing. I'll be buying an alternator tomorrow, but can one buy a replacement plug other than at the dealer or a junk yard?

Anyway, I feel reasonably certain that this will fix my code 18. Am I wrong? And if I'm not getting any codes in these tests, will an exhaust leak throw the O2 sensor off enough to cause the computer to over-supply fuel in the mixture? I know that certain Jeeps are susceptible to cracks in the exhaust manifold and I'm wondering if B2s circa 1987 are known for specific problems with the exhaust system that causes leaks? What kind of gaskets are there between the manifold and the pipe back to the cat?

Yeah, I know, I ask alot of questions.

I'm taking the B2 on a roadtrip to New York on Friday, and I'd far rather get 20-30 mpg than my present 15. I haven't even had time to worry about the cruise control but I'll be troubleshooting that before weeks end.

All input gratefully and graciously (in the event of my stupidity) accepted.

Thanks,
Dwight

 

The code 18 is an ignition code, do you feel the engine missing? I don't the alternator issue is relayed. If you don't have an engine miss I would clear the code and see if it returns.

An exhaust leak can screw up the O2 reading.

I have a link on cruse control in the tech info thread, it's my link.

 

Thanks Ken,

I cleared the codes between running the scan completely twice and twice got "Scan Successful" on the KOEO and KOER codes, only the Continuous Memory came up with 18 both times. I'm not hearing any noticable miss to the engine; however, it does tend to idle a little high at 1000 to 1100 most of the time.

I printed out the cruise control info yesterday (thank you so much for that, it is precisely what I was looking for) and planned to follow the step-by-step until I pulled out the alternator plug and couldn't get it back in. Somewhat put a damper on things today.

Things are at a standstill until I get to the junk yard tomorrow and find a plug, or get one at the dealership, that I can splice into the loom.

Any input on the exhaust manifold or potential leak locations?

Thanks,
Dwight

 

I really can't help with the exhaust leak since it's been a while since I worked on a 2.9 and mine didn't have an EGR system.

Can someone help with this????

I have the pinpoint tests for the code 18, I'll drop you an email.

 

Thanks Ken.

 

egr ( exuast gas recirculation) wont hurt your mpg too much at all sence it only work at highway criusing speeds to save on gas during longer trips so ive heard.

If this holds true then the egr should be closed during local trips where you stop and go often and go up and down hills. Perheps it may be stuk open check the egr control soloniod and egr valve see if anything is messed up