1988 2.9L ranger sputtering.

[kyle1468]

hey everyone so I have a 1988 Ford ranger with the 2.9l. I have had a rough go with it finally getting somewhere. So I had spark issue turned out to be a bad ECM replaced that song with new coil new spark plugs new wires new distributor and a new ignition control module. I had the trucks ignition timed by a shop and it fires right up but idles kind of high about 1500rpms. It idles okay but when you get on the road it is fine till about 2000 rpm’s and then it will sputter and buck and then an occasional backfire. If you give it a lot of throttle it backfires and falls on its face. It he barely any power aswell. I replaced IAC due to shop saying it was bad and the PCV valve asking with the PCV grommet as it was bad. Nothing changed. I want to note that the distributor has a slight whine noise when given throttle very faint. And the truck also idles great when spout is unplugged around 8-900 rpm’s. when it’s sputters and bucks while driving you can see tachometer dropping and sputtering aswell. Any info on what would be cause the horrible bucking and sputtering and no power would be greatly appreciated. Thanks.

 

[tw205]

Have you pulled any codes. Even if the CEL doesn’t come on. See if you have codes.
TPS will make the symptoms you reported. As will loss of tach signal.

 

[kyle1468]

Have you pulled any codes. Even if the CEL doesn’t come on. See if you have codes.
TPS will make the symptoms you reported. As will loss of tach signal.

Pulled codes got code 18 I’ve tested the TPS with a multimeter it checks out okay but could it still possibly be bad?

 

[tw205]

That code 18 is an issue. That is the loss of tach. I’m dealing with that as well. When the system losses tach it reverts to base timing. Causing low power and poor acceleration.
Unfortunately it sounds like you have replaced all the components that generate and use the tach signal. Distributor to ECM to ignition module to coil.

 

[kyle1468]

That code 18 is an issue. That is the loss of tach. I’m dealing with that as well. When the system losses tach it reverts to base timing. Causing low power and poor acceleration.
Unfortunately it sounds like you have replaced all the components that generate and use the tach signal. Distributor to ECM to ignition module to coil.

Yea it seems to be that that keeps being my issue I’ve replaced all I know to replace I guess it’s just time to look through wiring harness again but it just seems so odd as to why it idled high and sputters and backfires like it does because when spouts unplugged it is like it should be besides no power idles fine revs up etc just no power but once plugged spout in idles high backfires when given a good bit of throttle and then just runs like crap after 2k rpm’s.

 

[tw205]

Sure sounds like the signal from the ECU to the TFI is corrupt. Mine runs idles fine regardless of spout. Unplugged lower rpm and runs at 10• base timing. Plug it in and idle increases slightly and timing advance. As it should. But I still get that code 18. I’m also getting a 63 TPS voltage too low. I’m trying to determine if that can initiate a code 18.
Have you observed the timing after plugging in the spout. Does it advance and stay stable at Idle or is it jumping around.

 

[kyle1468]

Sure sounds like the signal from the ECU to the TFI is corrupt. Mine runs idles fine regardless of spout. Unplugged lower rpm and runs at 10• base timing. Plug it in and idle increases slightly and timing advance. As it should. But I still get that code 18. I’m also getting a 63 TPS voltage too low. I’m trying to determine if that can initiate a code 18.
Have you observed the timing after plugging in the spout. Does it advance and stay stable at Idle or is it jumping around.

okay i have the Spout wire coming from ecu untapped because i was checking it before i replaced ecu would that have anything to do with it? i don't have a timing light i had to take it to a local shop who timed it for me idles at like 8-900 with spout unplugged it increases to about 1200rpms when plugged in but idles consistent. i have just code 18 and 11 but 11 shouldn't be anything wrong. i put in the accel TFI from oriellys as that is all they had i don't know if maybe that's my issue i have the old motorcraft one i can try but before it broke down and i replaced all these parts it would run great but every once and a while the tach would just drop to zero for 5-10 sec and then come back to normal so i didn't know if that was the old TFI.

 

[tw205]

I don’t think removing the tape will affect anything. New bad parts are a thing now days. China has production goals but not quality. I don’t have a tach in my rig but you having one can see when it looses the signal. Intermittently.
Are you running an automatic transmission or manual? Idle on a manual should be around 900 rpm. Automatic will be higher in park or neutral as it’s measured in drive. I think.
If you get consistent code 18 with accel tfi but old motorcraft unit only fails occasionally then perhaps the trouble is the TFI old one heats up and fails were the new one is bad outta the gate.
Are you clearing your codes after making changes? If you unplug the spout with key on it will code 18. Last thing I do after changing or swapping is clear codes.

 

[kyle1468]

I don’t think removing the tape will affect anything. New bad parts are a thing now days. China has production goals but not quality. I don’t have a tach in my rig but you having one can see when it looses the signal. Intermittently.
Are you running an automatic transmission or manual? Idle on a manual should be around 900 rpm. Automatic will be higher in park or neutral as it’s measured in drive. I think.
If you get consistent code 18 with accel tfi but old motorcraft unit only fails occasionally then perhaps the trouble is the TFI old one heats up and fails were the new one is bad outta the gate.
Are you clearing your codes after making changes? If you unplug the spout with key on it will code 18. Last thing I do after changing or swapping is clear codes.

I have a Manual trans. i cleared codes after changing parts aswell. yea i have heard about the problems with the TFI from auto parts stores just hard to find a motorcraft one in stock anywhere. is there a way to test and see how the signal is coming from the computer and how it is coming from the pip/ i guess there got to be a way to test to see how my ecu signal is and looking to see if its dropping spark or isn't steady like it should be.