88 bronco 5.0 starts but wont run

[fv333]

I replaced the in tank fuel pump today . It didnt fix whatevers wrong . I dont have the time to do much more so I guess Ill have to give it to a mechanic and hope it wont be too expenxive .

My intuition tells me its the egr .

Maybe Ill try to pull codes again

 

[miesk5]

yo,

Engine Coolant Temperature Sensor (ECT)

read about it and how to test @ http://oldfuelinjection.com/index.php?p=28

 I know you replaced a coolant sensor;  here is a diagram showing the ECT and instrument panel TEMP gauge sender locations

http://www.supermotors.net/getfile/265237/original/GT-40%20lower%20intake.JPG

EGR ;

Ford EGR systems "...PCM will not operate the EGR valve unless it sees: The engine warmed up to normal operating temperature. TPS at partial throttle. TPS not at Wide Open Throttle (WOT). MAP/MAF must be indicating light or moderate load. A certain amount of computer clock time has to be elapsed..."

Stuck open will act like a vacuum leak and cause a rough idle and stalling

Testing; "...There shouldn't be any vacuum at the EGR valve at idle, except for perhaps a very light residual vacuum from the EVR. Check ALL of your vacuum lines FIRST, and the vacuum reservoir for leaks..."
Source: by SigEpBlue

Here are some DTCs that apply;

DTC 332 "...Insufficient EGR flow detected. Atop the EGR valve there is a sensor called the EVP (EGR Valve Position) sensor. It detects movement of the pintle iside the EGR valve. You can apply vacuum to the vacuum barb on the EGR valve and observe through the holes in the casting whether the valve is moving or not. It may just be dirty which requires some careful scrubbing. Otherwise, if the EGR valve is functioning and moving when vacuum is applied, the EVP sensor is suspect and the electrical connections to it should be checked first. (Computer needs to know the EGR valve position for emissions control)..."
Source: by greystreak92

DTC 34- EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the ****** side of the EGR by mouth. the egr is not closing properly which can cause detonation. remove the egr and clean off any carbon built up on it with carb cleaner and a brush if necessary.
Source: by miesk5 at Ford Bronco Zone Forums

Failed sensor, & as rla2005 (Randy) wrote; carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the ****** side of the EGR by mouth. the egr is not closing properly which can cause detonation. remove the egr and clean off any carbon built up on it with carb cleaner and a brush if necessary. read more
Source: by rla2005 (Randy) & miesk5

TUBE Removal Tip in an 89 5.0; "...BE CAREFUL HERE. USE PENETRATING FLUID HERE PRIOR TO REMOVAL. i BROKE ONE ON MY LAST BRONCO AND I HAD TO BUY A NEW ONE FROM THE DEALER FOR ALMOST $100..."
Source: by Waltman

 

[fv333]

Ive already changed the coolant sensor so Im good there . I was thinking about this today and simce the truck starts and runs for a second the computer is seeing the sensors as ok but when it checks the sensors required to keep it running when cold (remember it will run longer the warmer the engine gets and it will run perfectly when spraying starting fluid in the TB)it craps out . The TPS is one of those sensors so Im going to check prices and procedure . . I still havent checked codes but Ive never seen the check engine light come on so I doubt there are any but Ill check this weekend

Thanks Again

 

[miesk5]

yo,

I can't recall if I asked you if you see the CEL lit while first  starting?

Check Engine Light (CEL) comes on when the electronic engine control system is not working properly. The check engine warning indicator comes on briefly when the ignition switch lock cylinder is turned to ON, and should turn off when the engine starts. If the check engine warning indicator does not come on when the ignition switch lock cylinder is turned to ON or if it comes on while the vehicle is moving, the system is malfunctioning
If the CEL does not light up at all when starting it; then suspect that bulb is burnt-out or loose, socket was damaged by PO or shop, etc. or someone removed it, which does happen, unfortunately.
 

Throttle Position Sensor Testing, Replacement and Adjustment by Seattle Bronco

 

[fv333]

It comes on like it should with key on . I dont recall ever seeing it come while it was running . I looked again gfor the single wire and its nowhere to be found so I gues if I want to check codes Ill have to locate pin 48 on the computer . .Unless you know anohter way

I reread some of the replies and I missed the fact that theres something between the rear fuel pump and the front one . Im going to try to check it tomorrow if I can find the time . By thr way when I replaced the in tank fuel pump I noticed the sock on the end of the pump was ripped and not doing much filtering . I hope the injectors arent plugged with junk . I dont think they are since I cant imagine all eight getting plugged up at once

 

[miesk5]

yo,

Yes, Find Pin 48 (STI) and see the diagram on my prev reply; wire is White/ Purple

================

'88 Single-Function Reservoir

Used on '88-89 Broncos & F-series/E-series/Rangers/others with single tank dual-pump EFI. In this version, the only moving part is the tank-side inlet check valve. The return ports flow freely and are NOT connected to the reservoir. The engine-side supply port is open to the reservoir.

To test it, unplug the frame fuel pump, disconnect the engine-side supply (large) line, and cycle the key. If fuel flows out of the reservoir ******, the reservoir is working normally. If not, disconnect the tank-side supply (large) line, and cycle the key. If fuel flows out of the line, the reservoir check valve is probably stuck, or its internal filter is clogged.

A reservoir marked "DO NOT REMOVE CUP" does not contain a filter. For a replacement O-ring for the cup, buy a NAPA 3268, Fram CG3862, or equivalent filter.

READ MORE in post #14

============

Injector Test; "...With eveything connected normally & the key in RUN, pierce the OTHER wire (not the Red one) on any ONE injector & tap it BRIEFLY to ground. Do you hear half the injectors click open & then closed? Put a finger on each one to feel which ones are working. If some of them don't open, repeat the test, holding the ground SLIGHTLY longer each time, but never more than 3 sec continuously...Repeat this for the 2nd bank of injectors (just one with a different color wire)..."
Source: by Steve

This is hard to do due to eng not running and injector location

Testing & Servicing, Chapter 11, from Ford Fuel Injection and Electronic Engine Control: How to Understand, Service and Modify, 1988-1993 http://web.archive.org/web/20130530140512/http://www.yunost.ru/docs/Ford-injectors-book/Part11/Part11.pdf

page 241 - 244

 

[fv333]

I called several ford dealerships today to try to talk to the shop foreman . Got lucky on the third one . SHop foreman says hes seen 2 similar cases that drove the mechanics nuts and both turned out to be the PCM . I checked sround and found one at a place called orileys for 109 plus 40 core charge . Tomorrow or wed Im going to pull the PCM and check for water or rust etc .

What do you guys think?

 

[miesk5]

yo,

Yes, PCMs do get water damage, capacitor leakage, etc.

such as;

Capacitor Repair, Failures Due to Age; "...(A9x and same years ECM's) The patient in question is a remanufactured A9L unit. This ECM is the one from a little notch project I'm working on. It started giving some problems starting up, engine flooding, random hesitation, missing and stalls. I opened up the ECM (the car is running with a A9S unit) after the owner brought it for a checkup.What you see is the typical electrolytic capacitors leak, causing intermittent shorts/opens to the neighboring circuits/components and symptoms as the ones explained. Worst case scenarios with this type of failure, is a permanent no start and permanent damage to the PWB preventing it could be repaired. As soon as I replace the capacitors I'll update with the pictures showing the repairs. The following capacitor does not show any leakage problems however, it will also be replaced as a preventative measure..."  Source: by Joel5.0 at sbftech.com

Capacitor Repair in a 90 5.8
Source: by seedpress (dolittle) at Ford Bronco Zone Forums

http://broncozone.com/topic/20788-fuel-delivery-problem/

 

[fv333]

Where is the pcm located ?

Merry Christmas and thank you for all your help

 

[fv333]

Well I got the PCM out and theres a whole bunch of the connector pins are green and the outside shows definite water corrosion . When I opened it up I found a large brown stain around one of the caps ,although it dosent look like a leakage stain ,. The biggest thing I found is on the side of the board theres 2 transistors that are standing up and theres severe corrosion around tham . One looks really bad . Hoping that this is the problem .

 

[miesk5]

yo fv,

Merry Christmas to You & Your's!

TY!

I have tried to reply for awhile now, but lost all of the following twice; once when Comcast Blast highest cost internet blinked and 2nd time when I got logged out due to the Link.

Since you found the corrosion, etc. I think that could be the issue!

Next, check the PCM harness connector for corrosion, bent or missing stuff, etc.

Watch for static charge on fingers, etc when handling PCM

For PCM removal can you comment on following removal info and make changes?

PCM  can be seen behind drivers side kick panel

This is for most years; differences could be the bracket location & type... some later years have an 11mm bolt

Remove the ignition key from the ignition cylinder.

Disconnect the battery negative terminal.

remove the driver side kick panel,

Disconnect the PCM connector with a 10mm socket from the engine bay @ driver's side on firewall

Remove bracket from inside cab

 .

You'll find EEC Program Code

on the case for ordering a replacement.http://oldfuelinjection.com/?p=17

Identification, Bronco & Ford; "Every computer has a main sticker on the 60-pin connector that identifies the computer and holds the most information about the computer. If you have an EEC in your hands and wonder what it came out of this list is for you. If you are looking for an EEC in a junkyard or swap meets this is for you too. If you just wondered what computers Ford used in which vehicle this is also for you. I would not be upset if you printed this page off for your records, in fact I recommend taking it with you so you have an advantage finding that special EEC..."
Source: by Ryan M (Fireguy50)

How the EEC Computer Connector Comes Apart

Source: by Ryan M (Fireguy50)''

Also shows the 10mm Bolt http://oldfuelinjection.com/?p=74

Esp if Pins are damaged or what Ford describes as "terminal back-out".

 

[fv333]

Removal was easy . Theres the bolt you mentioned im the engine bay and also one on the back of the PCM behind the kick panel

Some of the pins,as I mentioned ,are green so Im pretty sure the female half of the connector has some corrosion also . Any suggestions on cleaning it without disassembling it

 

[miesk5]

yo fv,

This is by Ryan M again in his adding a chip to PCM and cleaning the J3 Port, but similar to cleaning the pins

It is imperative that you clean these contacts, if there isn’t good contact in this area, you will have problems. Use a swab to wipe off the excess protective grease, and then scrape off the solder mask (usually green in color.) Super fine sandpaper, steal wool, scotchbrite pad, pencil erasers, and small screwdrivers will work. Make sure you clean both sides, there should be 15 contacts on each side. Wipe the connectors with an alcohol pad to remove any dirt after using the scotchbrite pad. Visually inspect the surface for any residue on the contacts, one good tip is to look at the connector with a light shining on it, any spot that does not reflect the light needs to be recleaned

http://oldfuelinjection.com/?p=77

 

[fv333]

computer is on the way

 

[fv333]

Happy New Year to you and your family

Now the bad news . The new PCM did not fix the problem . Does the exact same thing . My neighbor seems to think its because when I replaced the in tank fuel pump I didnt replace the whole assembly ,only the pump . Ill tell you this Im ready to pull whats left of my hair out .

Im going to call the ford dealer again and try to speak to the shop foreman again . After that Im either going to sell it as is or take it to a shop and bend over .

 

[fv333]

map sensor???

 

[miesk5]

yo,

MAP Sensor; Testing, Symptoms & Overview; "...Surging, Rough idle, rich fuel condition, which may cause spark plug fouling,Detonation due to too much spark advance and a lean fuel ratio, loss of power and/or fuel economy due to ******** timing and an excessively rich fuel ratio, vacuum leak will reduce intake vacuum and cause the MAP sensor to indicate a higher than normal load on the engine. The computer will try to compensate by richening the fuel mixture and retarding timing -- which hurts fuel economy, performance and emissions

Testing, Symptoms & Overview; "...a multimeter that can read frequency is normally required to check the sensor’s output. But you can also use an ordinary tachometer because a tach can display a frequency signal. Here’s the procedure: Connect the two jumper cables the same as before, (see diagram in site) attaching each end terminal on the sensor to its respective wire in the wiring connector. If you want to measure engine vacuum so you can correlate it to a specific frequency reading, connect a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose. Turn the ignition ON and note the initial reading. The reading on the tachometer should be about 454 to 464 at sea level, which corresponds to a frequency output of 152 to 155 Hz. Start the engine and check the reading again. If the MAP sensor is functioning properly, the reading should drop to about 290 to 330 on the tachometer, which corresponds to a frequency output of about 93 to 98 Hz. No change would indicate a defective sensor or leaky or plugged vacuum hose..." a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose.

Driveability symptoms that can be caused by a bad MAP sensor, grounds or opens in the sensor’s wiring circuit, vacuum leaks in the sensor hose or intake manifold include hard starting, hesitation, engine misfires, stalling, rough or erratic idle, pinging, black exhaust smoke (rich fuel condition resulting in high hydrocarbon emissions), poor fuel economy and generally poor engine performance.

READ MORE
Source: by wellsmfgcorp.com 

===  Have you tried to jump to the EEC & Connector to do the Self-Test for Codes?

 

[fv333]

I looked for the wire but at the time I was feeling frustrated and ******  and today I just cant motivated . Ill try again tmo . Thanks

 

[miesk5]

yo, ok,

I hear ya.

You can try to backpobe the eec connector as described in one of my posts on page 1 of your thread here. And insert a solid wire in there or str8 pin w/alligator clipped wire to it

connect the STI @ Pin 48  to the negative baty terminal

 

[fv333]

I had it towed to a sshop on friday . Today the mechanic called and said theres  no signal from the ecm to fire the injectors ,He says he checked for power to them and its ok . He thinks there a problem with the distributor sending a signal to the computer that the injectors should be fireing  . Supposed to replace the hall effect sw and let me know