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SPFI severe hesitation


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Now, I now that this has been asked before, but please bear with me. I checked the search for hesitation, but most answers were for the fuel filter. My car has no low end till about 2,500 where the power will suddenly kick in. The engine will pull to redline easily, so this makes me think that the fuel filter is fine, cause its not starving for fuel in the high RPMs. It might be a bad TPS, but wouldn't that show up in the codes? It just boggs and misfires when I floor it from a stop, then slowly gains RPMs till all of a sudden, wham, the power kicks in. Almost like when the accelerator pump gave out on my GL. The fuel pump has been making loud grumbling noises since I got the car, but still, it runs good at high RPMs. Any advise would be extreemly appreciated, I want this engine to run well till I get my EJ22 swap all set up.

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  • 6 months later...

1987 DL SPFI D/R wagon: I got my flashing LED problem cured by disconnectig the green connectors. They had been left that way before I got the vehicle.

 

Also thanks to this forum, I did an oil change with Seafoam and stopped the ticking. I still have the converter rattle and may finally have to spend some money.

There's a severe lag on acceleration, slightly better when it's warmed up. Also, when cold, it take a long time to come down to a slow idle from 2000 RPM, but idles fine when warm . There is no misfiring when accelerating, it just acts like it's running very lean, and changing the fuel filter made no difference.

Is there a second fuel filter somewhere? Finally, this thread suggested cleaning the TPS contacts, but my Chilton doesn't mention the TPS or tell me where to locate it.

Thanks, Ray Mac.

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in my 88 GL, if I drive it cold uphill from a start, I have to be gentle on the gas otherwise it tries to bog down.

 

I'll have to check out the TPS once it warms up outside again (was really nice yesterday, snow this morning and gone already :confused: )

 

 

To find the TPS, locate the throttle cable on the intake. The TPS is on the other side of the intake from there. It's arranged so the throttle movement opens the flapper in the intake, as well as moving the TPS. It's a black rectangular box about 1/2" thick with 3 or 4 wires in a bundle coming out of it.

 

 

To test it, we'll need to find the correct contacts, and make sure there is smooth resistance output throughout the range of motion.

 

Hope this helps

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TPS is on the right side of the throttle body when looking at it from the front - however, I don't think the internal contacts can be cleaned, just the external connector

 

Nobody has mentioned plugs/wires/cap/rotor - all of those things are very common causes of misfiring at low rpms, as the engine is most sensitive to their condition at low rpms - all should be OEM and in good shape - I have had a bad cap/rotor/wires give me the same symptoms before - check all first - I don't see a fuel system component being an issue here, though I may be wrong

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TPS is on the right side of the throttle body when looking at it from the front - however, I don't think the internal contacts can be cleaned, just the external connector

 

Nobody has mentioned plugs/wires/cap/rotor - all of those things are very common causes of misfiring at low rpms, as the engine is most sensitive to their condition at low rpms - all should be OEM and in good shape - I have had a bad cap/rotor/wires give me the same symptoms before - check all first - I don't see a fuel system component being an issue here, though I may be wrong

 

ya, i'd try the usual tune-up stuff.. mine bogged at low rpm until i swapped in some new NGK's.. now she gets agoin pretty well...it also seems to run best when i let it warm up for 3-4 minutes before driving... no "bogging" at all...

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I read a post by MorganM that said his SPFI spun the big tires on dry pavement, so I know there's something wrong with mine.. it won't spin the stock tires on wet dirt without a clutch dump. Its not throwing any codes, I found the other green connecter, it had gotten stuffed back down the harness, the air filter, plugs, wires, dizzy cap, and rotor have all been replaced since I revived the car. CTS was recently replaced because it had crapped out. It idles happy, sits steady at any rpm, but still falls on its face when put to WOT. Timing is set to 20 before with the green connectors together. I brought my legacy beater back to life and drove it out of the woods, and that thing feels like a rocket ship compared to my loyale. Its CTS is screwed and some other things are getting fuzzy, so its not even running right and it smokes the loyale.

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  • 2 years later...

OK, I know this is ancient history, seeing as you've gone EJ, but did you ever solve this? It's sounding almost exactly like where mine is right now.

New plugs, wires, cap, rotor, air filter, etc. Timing set correct. Fuel seems fine - lots of power after the bog (~2000 - 2300 rpm). MAF checks out, TPS OK, CTS OK, etc. I have not checked the PCV yet - might that be an issue? I don't have much oil in the intake.

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check/clean your IAC. Cleaning that, and lubing the solenoid part of it makes a good sized difference in my car noted above.

 

It's still not perfect after cleaning it, but it's much better.

 

I know my PCV tubes are pretty caked with junk, so I may change them out sometime.

 

I'm also probably going to go EJ as well, partially because of this :rolleyes:

 

-Dave

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check/clean your IAC. Cleaning that, and lubing the solenoid part of it makes a good sized difference in my car noted above.

 

It's still not perfect after cleaning it, but it's much better.

 

I know my PCV tubes are pretty caked with junk, so I may change them out sometime.

 

I'm also probably going to go EJ as well, partially because of this :rolleyes:

 

-Dave

 

Yup, cleaned it twice. Once with Seafoam (let it soak in good, then dumped out). Once with brake cleaner.

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OK, just checked the PCV: lots of vacuum at idle (not warmed up). Is it normal to have constant vacuum? I thought it should pulse, and not go constant until you revved it up more?

 

This is a very strange and perplexing problem. The funny thing is that so many people have this type of problem with the SPFI, and yet so few actually resolve it. Many people have found a number of things that help it, or lessen it, but so few actually completely resolve it.

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It's perplexing because every little thing under the hood can affect it. I cleaned all the sensors, electrical connections, did the tune-up stuff, replaced all the old vacuum lines including making sure the pcv hoses were tight, and finally changed the o2 sensor and after all that no more hesitation issues. It's a process of elimination I guess...

 

-Doug

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It was mostly the timing in my case. Someone had set it with the connectors dissconnected, and I had checked it with them disconnected. With them connected, the timing was way off, I dialed it back in, and it ran way better.

 

Still a sackless POS, but at least it had some throttle response.

 

The EJ22 running on 3cyls, with the dead cyl with a burned valve, had almost exactly the same performance as the EA82 did once I got it running good. Same top speed, same slow pulling through the gears to get it going, everything.

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OK, just checked the PCV: lots of vacuum at idle (not warmed up). Is it normal to have constant vacuum? I thought it should pulse, and not go constant until you revved it up more?

 

This is a very strange and perplexing problem. The funny thing is that so many people have this type of problem with the SPFI, and yet so few actually resolve it. Many people have found a number of things that help it, or lessen it, but so few actually completely resolve it.

 

Man man man tell me about it :-\

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id guess one of the timing belts is off a little

 

Wouldn't that lead to more consistent poor running? I have not driven it yet today, but yesterday it was actually running quite good.

 

EDIT: So, to satisfy curiosities, I checked the t-belt alignment today. It looks just about bang on, maybe slightly off, but not a full tooth (BGD syndrome? -ie: crank pullies reversed?).

 

Anyways, checked oil level and it seems high. I've noticed the same issue with the Forester. Let the oil drain really good, pull filter and let drain some more, replace filter, add 4 litres oil, and the level seems high. Anyone else notice this?

(yes, I did crank it a few seconds and then start it and check for leaks)

I'll be camping for a week or so, we'll see what turns up.

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  • 2 weeks later...

So, hesitation REALLY bites when you've got no low range and you're running 27" Swampers! I found a pretty epic trail while camping, and couldn't get to the top (~6-7 miles) because of the hesitation/bog and the steepness of the trail. Oh well, I'll have to start swaping out parts and throw my D/R into it soon.

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